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SIMetrix User`s Manual

1. a rt R7 ri3 IDEAL Jos yi 100k m 330u 100 P8 u Ra les IMEG ohh 4 70 RS t Ra ay m vout 28u 2s0u lco L 1u pulse 0 loa 0 03 1m i2 c8 c2 74o C1 oe Joes Rts R16 R14 R2 os L 100n ISE itt JL T2 provides a current that is switched on for 1mS after a short delay A multi step analysis is set up so that the load current is varied from 10mA to 1A The output for all runs is 281 User s Manual 282 I2 pos V 4 94 4 9 2 pos iload 1 49 28 30 32 34 36 38 40 Time mSecs 2mSecs div We will now plot the a graph of the voltage drop vs the load current This is the procedure 1 2 Select menu ProbelPerformance Analysis You will see a dialog box very similar to that shown in Plotting an Arbitrary Expression on page 238 In the expression box you must enter an expression that resolves to a single value for each curve For this example we use yatx vout 0 minimum vout yatx vout 0 returns the value of vout when time 0 minimum vout returns the minimum value found on the curve The end result is the drop in voltage when the load pulse occurs Press OK and the following curve should appear Chapter 9 Graphs Probes and Data Analysis 1001 yatx vout 0 minimum vout V S 2m 10m 20m 40m 100m 200m 400m 1 iload Histograms The procedure for histogra
2. SIMPLIS Models D 0O G go te S1 bi i _ PAN O S LEVEL 0001 MOSFET D n k G ur re T g O S LEVEL 0011 MOSFET 126 Chapter 5 Components LEVEL 1032 MOSFET Cc BC Ty IRBE d LEVEL 1 BJT Model 127 User s Manual icalphaF X I RBE FCB eC RB izalphaR X I RBC FEB E LEVEL 2 BJT Model Generic Components 128 As explained in the overview generic components are devices that are defined by one or more parameters entered by the user after the component is placed The following generic components are available Device SIMPLIS Page support Saturable Inductors and Transformer No 130 Ideal Transformer Yes 132 Inductor Yes 134 Capacitor Yes 134 Resistor Yes 134 Potentiometer Yes 136 Transmission Line Lossless No 136 Transmission Line Lossy No 137 Chapter 5 Components Device SIMPLIS Page support Infinite capacitor No 135 Infinite inductor No 135 Voltage source Yes toe Current source Yes 137 Voltage controlled voltage source Yes 137 Voltage controlled current source Yes 137 Current controlled voltage source Yes 137 Current controlled current source Yes 137 Voltage controlled switch No 138 Voltage controlled switch with Hysteresis Yes 138 Delayed Switch No 139 Parameterised Opamp Yes 140 Parameterised Opto coupler No 141 Parameterised Comparato
3. ccceeeeeeceeeeeeeteeeneeeees 353 SIMetrix Command Line Parameters ccceeeeeee 354 Using StartUp Mls aiaeei iair iaie 355 Configuration Settings cccceeseeeeesseeeeeeeeeeetsneeteeeeeaees 355 OVAN OW ar a E elas Ena aa A e a a EA 355 Default Configuration Location sesseeseeseeeeeee 355 Application Data Directory 00 cee 355 Specifying Other Locations for Config Settings 356 OPTIONS iiin e a E E telecon eves 357 OVOIVICW eee cs neserestigie inden a eiie eksi naa viene 357 Using the Options Dialog cecceceeseeeeseeeeeees 357 Using the Set and Unset commands 006 363 Startup Auto Configuration 00 eee 383 OVO IVIGW EAA EET 383 Whatis Set Up teins date ren eaa kines 383 Auto Configuration Options c eeeeeeeseeeeeeenees 383 Table of Contents Installation CUStOMISING cceeeeeeetetteeeteetes 385 Colours and Fonts ceeeceeeeeeeeeeeeeseeeeeeeeeeeeseaeeseeeeneees 385 GOlOUIS 2 2icvesvcpads steed E AS 385 FONtS iets dr duwhirn tate ai hae 385 Using a Black Background seeen 387 Startup Scripten a sien eae ei ee aaa 387 User s Manual Chapter 1 Introduction Installation and Licensing Full installation and licensing instructions may be found at http www simetrix co uk app users htm Install CD The install CD contains the installation files but also contains other useful material such as model documentation and scri
4. Parameter Description Off Resistance Switch resistance in OFF state On Resistance Switch resistance in ON state Threshold Average threshold Switches to on state at this value plus half the hysteresis Switch to off state at this value less half the hysteresis Hysteresis Difference between upper and lower thresholds Switching Time Time switch takes to switch on Note that this is the Onf total time from the point at which the switch starts to switch on to the point when it is fully switched on Switching Time Time switch takes to switch off Off Initial condition Sets the initial state of the switch at the start of the simulation Older versions of this model did not include the switching time parameters If you wish to update a switch with hysteresis already placed on a schematic to include this parameter use the Edit Add Properties menu to change the PARAM_MODEL_NAME property to VC_SWITCH_V3 Delayed Switch Implements a voltage controlled switch with defined on and off delay This model can be used to implement relays Switch action is similar to the Switch with Hysteresis described above This device can be placed on a schematic with the menu PlacelAnalog Functions Delayed Switch Parameters are Parameter Description Off Resistance Switch resistance in OFF state On Resistance Switch resistance in ON state Threshold Low Switch switches off when control voltage drops below this threshold Threshold
5. I L3 P Y2 tran5 S1 P Y1 I L3 P A Y2 Y1 15 10 S1 P V 1 96 198 2 2 02 204 206 208 21 212 Time kSecs 20Secs div x 2 11322kSecs y 3 43892A Current and Voltage plotted on separate Grids AutoAxis Feature When you plot a new curve on an existing graph SIMetrix will select or if necessary create a compatible axis for that curve The decision is made on the basis of the curve s Units i e voltage current etc The rules it follows are 1 If the currently selected axis or grid shown by black axis line has the same units as curve to be plotted or if it has undefined units designated by a on label that axis will be used Chapter 9 Graphs Probes and Data Analysis 2 If any other axis or grid has compatible units i e same as curve or undefined that axis will be used 3 Tf no axes exist with compatible units a new axis not grid will be created to accommodate the curve The above works for all plots made using random probes For plots created with fixed probes the above is the default behaviour but this can be changed See Fixed Probes on page 223 for more details For plots created using the Curve command at the command line the AutoAxis switch must be specified e g Curve AutoAxis L3 P Manually Creating Axes and Grids Two toolbar buttons Create new grid and Create new axis allow manual creation of new axes and grids These will be initially emp
6. Parameter Description Input Resistance Differential input resistance Output Resistance Series output resistance Hysteresis Difference between switching tresholds The output will switch from low high when the differential input voltage rises above half the hysteresis The output will switch from high low when the differential input voltage falls below half the hysteresis Output Low Voltage Unloaded output voltage in low state Output High Voltage Unloaded output voltage in high state Delay Delay between threshold crossing and start of the output changing state Rise Fall Time Output rise and fall time VCO Implements a simple voltage controlled oscillator with a digital output You can place a VCO on the schematic using menu PlacelDigital GenericlVCO Analog in digital out Its parameters are Parameter Description Frequency at VC 0 Output frequency for a control voltage of zero Gain Hz V Change in frequency vs change in input voltage Verilog A Library If you have a VX version of the product you may also use one of the Verilog A implemented devices available under the Place Analog Functions Verilog A Library These devices are defined using the Verilog A language The Verilog A code for these devices may be found in the support valibrary directory Windows or share valibrary directory Linux under the SIMetrix root Currently there are 4 Verilog A library devices as described in the following paragraphs V
7. Transient AC DC Noise TF SOA Options Analysis Mode Transient Transient parameters a Stop time 3 i DC Sweep Data output options Noise Start data output 0 V Defaut E PRINT step 200r F Default DCOP Output all data Output at PRINT step Real time noise Enable realtime noise Define Monte Carlo and multi step analysis Enable multi step Define Selected mode None Define Snapshots Advanced Options 2 Click AC check box and uncheck the Transient check box The details of the AC sweep have already been set up click the AC tab at the top to see them 3 Run the simulation this will open a new graph sheet Tutorial 2 A Simple SMPS Circuit In this tutorial we will simulate a simple SMPS switching stage to demonstrate some of the more advanced plotting and waveform analysis facilities available with SIMetrix 30 Chapter 2 Quick Start ESR_Ci 80m D2 V1 9 P3 murd310 3 m ci 150u 30u Ao l o i Output IRF750 47 P2 ai v2 X C Pulse 0 5 0 50n 50n 1 95u 5u You can either load this circuit from EXAMPLES Tutorials Tutorial2 see Examples and Tutorials Where are They on page 21 or alternatively you can enter it from scratch The latter approach is a useful exercise in using the schematic editor To do this follow these instructions 1 Place the components and wires as shown above 2 The probe labelled O
8. cccsecccceeseeceseeeeeseeeeescneeeesceeeesoeers 304 Keyboard etnea a a a E eis 304 Chapter 11 Command and Function Reference Command SUMMALY ccceeeeeeeeeeeeeeeeeeeeeeneeeeeeeeneeteaee 309 Reference A 309 User s Manual 12 Def Key eai aa a ae ae A aa aaa E a Def MENU iror ve Aled 801 11 E IKON o AEAEE TT ETET ReadLogicCompatibility 0 0 2 0 eeceeeeeeeeeteeeeeeees Function SUMMAPY iieii sareni ihein eade dieat as Function Reference ccesscccesceeeeeeeeeeeeeeesseneeseeeeeees abs real compleX sssnsurcsrnrirunrisuirininrinrernrernnnenna arg real COMPIeX ssseeeeereeeeessrresrrrerrrrerrrrsrresens arg_rad real COMplex eesceeeseeeeeeneeeeeneeeeeneees atan real COMPIeX eeeeeeeseeeeeeteeeeeneeerenneeeeneeee COS real COMPIEX 0 2 eeeeeeeeeeeeeneeeeneeeeeneetesneeereneees Cb real COMPIleX eeeeeeeseeeeeeneeeeeeeeeeneeeeeeaeeeeneees OMT TOA ccs csc EE E T XP real COMPICX ee eeeeeseeeeeeeeeeseeeeeeneeeesneeeeeneeees fft real String iiiki re esip aaraa FIR real real real essseesesseeeeeceeeeseeesenenes Floor e l ssri nae GroupDelay real complex eeeeeeeeeeteeeeeeeteees Histogram real real n se Iff real ANY AMY riiin WR real real real c c im real complex imag real complex ee integ real eriiic ace aeaa ean aea aaa aai Interp real real real real eeeeneeen ISCOMpleX ANY sepesi fetes cess ies
9. Chapter 2 Quick Start Q3 Q2N2222 J Amplifier Output I 2 2k R3 _ CLOAD l l l l ai i 50 Q2N2222 l 100p j v2 R5 aiH 22221 470 i l l l l D AC 1 0 Pulse 0 100m 0 10n 10n 5u R4 i ea As you drag the mouse a rectangle should appear Release the mouse The area enclosed will turn blue e V1 Er Amplifier Output AC 1 0 Pulse 0 100m 0 10n 10n 5u The blue wires and components are said to be selected To move them Place the cursor within one of the selected components V1 say then press and hold the left mouse key Move the mouse to the right by two grid squares then release the left key 27 User s Manual 5 Unselect by left clicking in an empty area of the schematic This is what you should now have AC 1 0 Pulse 0 100m0 10n 10n 5u 6 Wire in the capacitor C1 as shown below using a similar procedure as for the resistor R6 Q3 Q2N2222 7 Amplifier Output CLOAD Q2 Q2N2222 InF is obviously far too high a value so we will try 2 2pF To change the component s value proceed as follows 1 Double click C1 You should see the following dialog box appear 28 Chapter 2 Quick Start J Choose Component Value E Device Value Initial Conditions Base 1 5 Seres O
10. Displaying Device Operating Point Info The menu Bias Annotation Display Device Bias Info will display in the message window the node voltages pin currents and total power dissipation for the selected schematic component Note that power dissipation is calculated from the node voltages and currents List File Data A great deal of information about each device in the circuit can be obtained from the list file Use command shell menu Graphs and DatalView List File or Graphs and Chapter 9 Graphs Probes and Data Analysis DatalEdit List File to see it Also see the Simulator Reference Manual for more information about the list file Other Methods of Obtaining Bias Data You can also display a voltage or current in the command shell without placing any component on the schematic For voltages place the mouse cursor over the point of interest and press control N For currents place the cursor over the component pin and press control I Bias Annotation in SIMPLIS The above apply to operation in both SIMetrix and SIMPLIS modes When in SIMPLIS mode the de values displayed represent the results at time 0 For AC analysis this will be the time 0 value for its associated POP analysis Bias Annotation Display Precision By default bias annotation values are displayed with a precision of 6 digits To change this select command shell menu FilelOptions General then edit the value in box Bias Annotation Precision in the Schematic sheet
11. Select the AC DC Noise or TF tab as required 2 Inthe Sweep Parameters section press the Define button 3 In the Sweep Mode section select Monte Carlo Chapter 12 Monte Carlo Analysis 4 In the Parameters section enter the required value for the Number of points 5 For AC Noise and TF you must also supply a value for Frequency Setting up a Multi Step Monte Carlo Run 1 Select schematic menu SimulatorlChoose Analysis Select the AC DC Noise Transient or TF tab as required 2 Define the analysis as required 3 In the Monte Carlo and Multi step Analysis section check the Enable multi step box then press the Define button This will open E j Define Multi Step Analysis EA Sweep mode Step parameters Device Start value Parameter Stop value ar a aly Model parameter Number of steps I Temperature Decade Group curves Monte Carlo List onapsnot 4 In the Sweep mode section select Monte Carlo 5 In the Step Parameters section enter the number of steps required Running a Monte Carlo Analysis Monte Carlo analyses are run in exactly the same way as other analyses Press F9 or equivalent menu Setting the Seed Value The random variations are created using a pseudo random number sequence The sequence can be seeded such that it always produces the same sequence of numbers for a given seed In Monte Carlo analysis the random number generator is seeded with a new value
12. E Defaut DCOP Output all data Output at PRINT step Real time noise Enable realtime noise Define Monte Carlo and multi step analysis E Enable multi step Define Selected mode None Define Snapshots Advanced Options Help Choose Analysis Dialog You can also enter the raw netlist commands in the F11 window The contents of this window remain synchronised with the Choose Analysis dialog box settings so you can freely switch between the two methods The Choose Analysis dialog box does not support sensitivity and pole zero analysis so these methods must be set up using the F11 window 174 Chapter 7 Analysis Modes Running Simulations Overview Once an analysis has been set up using the procedures described in this chapter a simulation would normally be run in synchronous mode perhaps by selecting the SimulatorlRun menu In synchronous mode you cannot use any part of the program while the simulation is running There are also other methods of running a simulation You can run a simulation for a netlist directly and you can also run in asynchronous mode These are explained in the following sections Starting Pausing and Aborting Analyses Starting an Analysis To start a simulation in normal synchronous mode use the Simulator Run menu press the F9 key or press the Run button on the Choose Analysis Dialog box shown above A dialog box will show the status of the simulation Pausing an
13. Edit property pin arc peak graph symbol editor F8 Edit reference schem Ref cursor to Move ref Ref cursor to next trough previous trough graph graph F9 Start simulation Open Last Schematic F10 New graph sheet F11 Open close simulator command window schem F12 Zoom out schem Zoom in schem graph symbol graph symbol editor Insert Paste Copy Delete Delete Cut Home Zoom full graph Zoom full selected schem symbol axis graph End Page Up 306 Chapter 10 The Command Shell Key Unshifted Shift Control Alt Page Down Up Scroll up schem graph Increment Big scroll component up schem potentiometer schem Scroll up selected axis graph Down Scroll down schem Decrement Big scroll graph component down potentiometer schem schem Scroll down selected axis graph Left Scroll left schem Scroll left selected Big scroll graph axis graph left schem Right Scroll right schem Scroll right Big scroll graph selected axis right graph schem SPACE TAB Step main cursor Step reference cursor ESC Abort macro cancel operation or pause simulation 307 User s Manual Chapter 11 Command and Function Reference There are over 500 functions and about 240 commands available but only a few are covered in this chapter Details of all available functions and commands can be found in the Script Reference Manual This is available as a PDF file on the install C
14. In most cases the SIMPLIS model will be regenerated when one of these parameters is edited The following table explains the meaning of the parameters for each device 123 User s Manual Device Parameters Diodes Maximum current This should be set to the maximum current rating of the device The conversion process needed to create the SIMPLIS model is often able to look up this value in a database If not you will be prompted to enter a suitable value Reverse Voltage Set this to the largest steady voltage that the diode will be subjected to during normal operation This is not the breakdown voltage of the diode but the voltage that is used to define reverse leakage current Temperature This parameter will set the simulation temperature used when extracting the SIMPLIS model It will only be meaningful if the temperature is properly supported in the SPICE model Number of Segments Set this to 2 or 3 3 segments will be more precise but run slower Initial condition Set this according to the expected state of the diode at the start of the simulation run This will help with locating an initial operating point BUTs Model level This may be set to 1 or 2 1 runs faster while 2 provides more accurate results See diagrams below for model structures used Max Collector Current Set to specified maximum collector current for device Device is ON at t 0 Check this if the device will be in an ON state at the start
15. User s Manual 166 STEP 1 Select a suitable category forthis part Cheese Category for SXOA1000 if you cant find one press New Category Unassigned and enter a new category of your choice STEP 2 Select a suitable symbol for this part Define Symbol for SXOA1000 Select a symbol from the drop down box or press Auto Create Symbol to create a new one AD587 F selecting an existing symbol you must make Pin order 4 sure that the pin order matches the model definition shown below Press Help for assistance you use Auto Create Symbol the pin order will not need to be changed 5 Enter a suitable category for the part under Choose Category for xxx where xxx is your model name You can create a new category if desired by pressing New Category 6 Using the drop down box under Define Symbol for xxx select a suitable symbol for your model An image of the symbol will be displayed so you can check if it is appropriate If no suitable symbol is available press Auto Create Symbol and one will automatically be created You can edit this symbol later if required 7 If you selected an existing symbol you must check that the pin order matches that of the model itself The model text is displayed under Electrical Model xxx If the pin order needs changing use the up and down arrow keys to rearrange the pins as appropriate 8 Press Ok then place symbol as usual Steps 4 to 8 abo
16. Vector Maximum value Default 00 Options array Possible values are xSort Sort output in order of x values nolnterp Don t interpolate Returns array of values holding every minimum point in the supplied vector whose value is below argument 2 The value returned if noJnterp is not specified is obtained by fitting a parabola to the minimum and each point either side then calculating the x y location of the point with zero slope If noInterp is specified the values are those found in argument without any interpolation The vector returned by this function has an attached reference which contains the x values of the minimum points If xSort is not specified the vector is arranged in order of ascending y values i e smallest y value first largest last Otherwise they are organised in ascending x values Minimum real complex real real Start x value End x value Returns the smallest value found in the vector in the interval defined by start x value and end x value If the vector is complex the operation will be performed on the magnitude of the vector norm real complex Returns the input vector scaled such that the magnitude of its largest value is unity If the argument is complex then so will be the return value 327 User s Manual 328 ph real complex phase real complex Returns the phase of the argument ph is identical to phase and return the phase in degrees The phQ and phase function
17. all Location and base name of global catalog file usually referred to as ALL CAT Default sxgph Options File extension used for dialog graph files See Chapter 7 Script Reference Manual Creating and Modifying Toolbars for details Default 0 3mm Options Width of printed graph grid dialog lines in mm See also CurvePrintWidth 369 User s Manual 370 Name Type Description User interface support GroupPersistence Numeric Default 3 No Sets the number of groups that are kept before being deleted See Plotting the Results from a Previous Simulation on page 251 GuiEditPropertyEnabled Boolean Default false Options If set allows visible dialog properties in the schematic to be edited using GUI actions HideSchematicGrid Boolean If set the schematic grid Options will be suppressed dialog HighlightIncrement Numeric Default 1 No Highlighted graph curves are thicker than normal curves by the amount specified by this option HistoCurveStyle Text Default stepped Options Sets histogram curve style dialog InhibitAutoCD Boolean The current working No directory is automatically changed to the displayed schematic when you switch schematic tabs Set this option to disable this feature InitSchematicSimulator Text Default SIMetrix Options Simulator mode for new dialog schematic If set to SIMPLIS all schematics will start in SIMPLIS mode Otherwise they start in SIMetrix mode Inte
18. gt Chapter 9 Graphs Probes and Data Analysis J Define Fourier Plot Method Fourier Method Plot Frequency display FFI Magnitude Resolution Hz 100 Continuous dB i Fourier Phase or i Stopfreg Hz 10k a Signal info E Log X Axis F Know fundamental frequency Frequency 100 FFT interpolation The spectrum will be calculated using Num points 4096 a an exact number of cycles of the fundamental frequency Order 2 ic Estimated calculation time 0 00393 Advanced Options SIMetrix offers two alternative methods to calculate the Fourier spectrum FFT and Continuous Fourier The simple rule is use FFT unless the signal being examined has very large high frequency components as would be the case for narrow sharp pulses When using Continuous Fourier keep an eye on the Estimated calculation time shown at the bottom right of the dialog A description of the two techniques and their pros and cons follows FFT Fast Fourier Transform This is an efficient algorithm for calculating a discrete Fourier transform or DFT DFTs generally operate on evenly spaced sampled data Unfortunately the data generated by the simulator is not evenly spaced so it is therefore necessary to interpolate the data before presenting it to an FFT algorithm The interpolation process is in effect the sampling process and the Nyquist sampling theorem applies This states that the signal can be perfectly reproduce
19. Bias Annotation and Long Transient Runs If you are running a long transient analysis and plan to use bias annotation extensively you might like to set a simulator option that will make this process more efficient The simulator option is OPTIONS FORCETRANOPGROUP This forces a separate data group and separate data file to be created for the transient analysis bias point data Unless tstart gt 0 bias point data is usually taken from t 0 values The problem with this approach is that to view a single value the entire vector has to be loaded from the data file to memory This isn t a problem if the run is only a 100 points or so but could be a problem if it was 100 000 points It can take a long time to load that amount of data By specifying this option the bias point data is stored separately and only a single value needs to be read from the file This is much more efficient Saving Data Saving the Data of a Simulation The simulator usually saves all its data to a binary file stored in a temporary location This data will eventually get deleted To save this data permanently select menu FilelDatalSave You will be offered two options Move existing data file to new location This will move the data file to location that you specify and thus change its status from temporary to permanent As long as the new location is in the same volume disk 279 User s Manual partition as the original location this operation will be
20. Bus connections can be passed through a hierarchy in much the same way as normal single wire connections Bus connections are defined by the underlying schematic The symbol representing the schematic does not require any special treatment Creating Bus Connections Using the Bottom Up Method 1 Enter the schematic in the usual way 2 To define a bus connection place the part HierarchylPlace Module Bus Port instead of the usual Module Port Select the device and press F7 to define the port name and bus size i e the number of wires in the bus 3 Save schematic as a Component 75 User s Manual 76 4 Select menu HierarchylOpen Create Symbol for Schematic 5 Edit symbol if required then save Changing the Bus Offset in the Parent Schematic The bus connection in the parent schematic has a size that is determined by the module port in the child schematic However the offset that is the first wire it connects to in the bus in the parent can be changed on a per instance basis To do this proceed as follows 1 Select the label next to the bus pin This will be of the form A B where A is the start wire default is 0 and B is the final wire Note that if you edited an existing symbol to add a bus connection you may not see this label If so select the component then menu HierarchylUpdate Bus Connections 2 Press F7 then enter the new offset and OK You will see the label change accordingly For example suppose the
21. Edit Modes SIMetrix has three alternative edit modes that affect how wires are treated during move operations and also the behaviour when superimposed connecting pins are separated These are 1 Classic This is a basic rubberbanding mode where wires are fixed at one end and follow the component at the selected end When superimposed pins are separated no wire is created between them This is the method used for all SIMetrix version up to and including release 5 2 hence the name classic 2 Grow wire The wire editing is the same as for classic but when superimposed pins are separated a wire is created to maintain the electrical connection 3 Orthogonal As grow wire but wires are edited in a manner so that they are kept at right angles as much as possible The default setting is Classic To change to a new setting proceed as follows 1 Select command shell menu File Options General 2 In schematic tab in the Edit Mode section select the mode of your choice Note that this change will not affect currently open schematic sheets Bus Connections SIMetrix provides the Bus Ripper symbol to allow the connection of busses To Add a Bus Connector 1 Select the menu PlacelConnectorsIBus Ripper This will display dialog J Define Bus Ripper Ripper parameters Bus Name optional Start index 0 a End index 3 8 Style Top diag Gree ate Enter a bus name if you require it 2 Start ind
22. SCRIPT directory This file is actually identical to the built in definitions except for the UNIV family which cannot be redefined Please refer to the Digital Simulation chapter of the Simulator Reference Manual for full details on logic compatibility tables File Format The file format consists of the following sections Header In Out resolution table In In resolution table Out Out resolution table Header The names of all the logic families listed in one line The names must not use the underscore _ character In Out resolution table 313 User s Manual 314 A table with the number of rows and columns equal to the number of logic families listed in the header The columns represent outputs and the rows inputs The entry in the table specifies the compatibility between the output and the input when connected to each other The entry may be one of three values Fully compatible Not compatible but would usually function Warn user but allow simulation to continue Not compatible and would never function Abort simulation In In resolution table A table with the number of rows and columns equal to the number of logic families listed in the header Both column and rows represent inputs The table defines how inputs from different families are treated when they are connected The entry may be one of four values Row take precedence Column takes precedence Doesn t matter Currently identical to
23. User s Manual The Plot Journal feature allows you to save the plots in the current graph sheet for later reconstruction This doesn t save the data it saves the vector names and expressions used to create the graph s curves In fact this is done by building a SIMetrix script to plot the curves Update Curves Make sure that no curves are selected then select graph menu PlotlUpdate Curves The curves currently on the graph sheet will be redrawn using the current simulation data Although this would usually be the latest simulation run you can also use this feature to restore the curves back to those from an earlier run Use the Graphs and DatalChange Data Group menu to select earlier data For more information see Plotting the Results from a Previous Simulation on page 251 Options By default all curves are redrawn that is the older ones are deleted You can change this behaviour so that older curves are kept Select menu PlotIUpdate Curves Settings then uncheck the Delete old curves box If there are curves that you would like to remain fixed and so won t be updated simply select them first This behaviour can be overridden using the menu PlotlUpdate Curves Settings Simply uncheck the Ignore selected curves box Plot Journals First create a plot journal using the menu PlotlCreate Plot Journal then choose a file name The file created has a sxscr extension its the same extension used by scripts bec
24. on page 296 for more details file filename If specified outputs result to filename The values are output in a format compatible with OpenGroup text See OpenGroup on page 313 315 User s Manual 316 append filename As file except that file is appended if it already exists noindex If the vector has no reference the index value for each element is output if this switch is not specified noHeader If specified the header providing vector names etc will be inhibited plain If specified no index as noindex and no header as noHeader will be output In addition string values will be output without enclosed single quotation marks force File specified by file will be unconditionally overwritten if it exists clipboard Outputs data to system clipboard names names Semi colon delimited string providing names to be used as headings for tabulated data If not specified the vector names are used instead width width Page width in columns for tabulated data If not specified no limit will be set lock If specified with file a lock file will be created while the write operation is being performed The file will have the extension lck This can be used to synchronise data transfers with other applications Under Windows the file will be locked for write operations On Linux the file will have a cooperative lock applied expression Expression to be displayed If expression is an array all valu
25. 7 Defaut E Noise Voltage j 7 Defaut Mae Caoa Transfer function tolerance UU Enable DCOP Circuit conditions 0 Temperature 27 V Defaut Initial condition oe force res Ohms 1 e E Defaut R Open console Verilog simulator CVER e for Verilog process Tuning resolution tfs H Note thet the Verilog HDL group will only be displayed in versions with the Verilog HDL feature Tolerances Relative Tolerance Controls the overall accuracy of the simulation The default value is 0 001 and this is adequate for most applications If you are simulating oscillator circuits it is recommended to reduce this to 0 0001 or lower Increasing this value will speed up the simulation but often degrades accuracy to an Current Tolerance Voltage Tolerance Circuit Conditions Temperature Initial Condition Force Resistance List File Output Expand subcircuits Parameters Monte Carlo Seed Chapter 7 Analysis Modes unacceptable level Sets the minimum tolerance for current It may be beneficial to increase this for circuits with large currents Sets the minimum tolerance for voltage It may be beneficial to increase this for circuits with large voltages Circuit temperature in C Initial conditions apply a voltage to a selected node with a force resistance that defaults to 10 This option allows that force resistance to
26. Any text already in command line is overwritten 5 Immediate mode Command is executed immediately even if another operation such as a simulation run or schematic editing operation is currently in progress For other options the command is not executed until the current operation is completed Only a few commands can be assigned with this option See DefKey documentation in the Script Reference Manual for full details Valid key labels Function keys F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12 INS DEL HOME END PGUP PGDN LEFT RIGHT UP DOWN TAB BACK ESC NUMI NUM2 NUM3 NUM4 NUM5 NUM6 NUM7 NUM8 NUM9 NUMO NUM NUM NUM Insert key Delete key Home key End key Page up key Page down key gt t 4 Tab key Back space Escape key Keypad 1 Keypad 2 Keypad 3 Keypad 4 Keypad 5 Keypad 6 Keypad 7 Keypad 8 Keypad 9 Keypad 0 Keypad Keypad Keypad Chapter 11 Command and Function Reference NUM Keypad NUM Keypad _SPACE Space bar must always be shifted see below All letter and number keys i e A to Z and 0 to 9 referred to by letter number alone Shifted keys Any of the above prefixed with any combination of S for shift C for control or A for alt Note that in windows the right hand ALT key performs the same action as CONTROL ALT Notes Unshifted letter and number key definitions will not function when a text edit window such as the simul
27. Count k 100 div The graph shows the variation in gain for 1000 samples Using the histogram feature a statistical distribution of the above can easily be plotted Setting up a Swept Analysis In the AC DC Noise or Transfer Function analysis sheets select the Define button in the Sweep Parameters box This will bring up the following dialog 185 User s Manual J Define Sweep Mode Sa Sweep mode Parameters Device Device name Parameter Parameter name restail Model parameter Frequency 100k S Temperature Number of points 10 z Freguency Monte Carlo coal Help Select the desired mode on the left then enter the necessary parameters on the right The parameters required vary according to the mode as follows Mode Parameters Device Device component reference e g V1 Frequency AC Noise and TF only Parameter Parameter name Frequency AC Noise and TF only Model Parameter Model name Model parameter name Frequency AC Noise and TF only Temperature Frequency AC Noise and TF only Frequency not available for DC None Monte Carlo Number of points Frequency AC Noise and TF only DC Sweep 186 Operates in any of the sweep modes described on page 182 except Frequency Repeats a DC operating point calculation for the range of circuit parameters defined by the sweep mode Setting up a DC sweep 1 Select menu SimulatorlChoose Analysis 2 Select DC sweep check box on the right 3
28. Dual Complimentary 4 term mixed_mode sxslb NPN schottky passives sxsib NPN schottky 5 pin semiconductors sxsib Creat NPN 3 terminal sheet_text sxsib pn NPN 4 teminal sources sxslb NPN cascode F simplis sxslb NPN darington intersil_controllers sxslb NPN dual NPN dual 4 term current miror F sor NPN quad no substrate g NPN quad with substrate t Pe ce ee er are NPN themal 5 terminal 3 z EE NPN ThemalTrak t PNP schottky nog PNP schottky 5 pin t oF 4 PNP 3 terminal am s PNP 4 terminal to t E i PNP darlington i aii PNP dual PNP dual 4 term current mirror DMD med fm inte tn ec ee J r Pelalil lil E 108 Sear er eer eee eno tonal ren e Note that the box can be resized in the usual way The symbols available to the schematic editor are stored in library files which conventionally have the extension SXSLB Only symbols in installed libraries are available for placing a new part Note however that once a symbol is placed on a schematic a copy is stored locally so you can still view a schematic that uses symbols that are not installed The symbols in each file are grouped into categories using a tree structure as shown above in the Symbols box The manager allows you to install or uninstall library files to move symbols between files or categories to delete symbols to copy symbols and to create new categories You can also cr
29. Linux There are so many Linux distributions available that it is impossible to fully test and support each and every one We therefore only fully support the following distributions Redhat Enterprise Linux 3 4 and 5 Currently only 32 bit versions are supported SIMetrix will run correctly on other distributions However if you use an unsupported distribution and you have difficulties with running SIMetrix on that distribution we will not be able to offer assistance unless we can reproduce that difficulty with a supported distribution SIMetrix will usually run on any distribution that uses glibc 2 3 2 or later and gcc version 3 2 3 or later Hardware SIMetrix will run satisfactorily on any hardware that is sufficient to run the machine s operating system 19 User s Manual 20 Recommended System If you regularly run large circuit simulations or long runs on smaller circuits we recommend investing in the most powerful CPU available A large RAM system can be useful as this will allow caching of simulation data This will speed up plotting results if a large amount of data is generated The data is stored to disk in an efficient manner and therefore substantial RAM is not essential unless the circuits being simulated are very large indeed 20 000 MOSFETs requires around 64MBytes A high performance bus mastering SCSI disk system will improve simulation performance a little About the 64 bit Version A 64 bit versio
30. Note that the DC operating point is calculated automatically for all the other analysis modes described above although for noise analysis the results are not stored After a DC operating point has been completed you can annotate your schematic with markers to display the voltages at each node Press control M on the schematic to place a single marker or select the popup menu Bias AnnotationlAuto Place Markers to automatically place markers on all nodes See Viewing DC Operating Point Results on page 278 for full details Other Analysis Modes Real time noise An extension of transient analysis which enables noise generators for noisy devices using the same equations used for small signal noise analysis See Real Time Noise on page 193 Transfer function Similar to AC but instead of calculating the response to a usually single input it calculates the response from all signal sources to a single output See Transfer Function on page 195 Sensitivity Calculates the sensitivity of a specified output to device and model parameters See Sensitivity on page 197 Multi step Analyses Transient AC DC Noise and Transfer Function analyses can Chapter 3 Getting Started be run in an auto repeat mode while stepping a user defined parameter See Multi step Analyses on page 200 Monte Carlo Analysis See Monte Carlo Analysis on page 332 Setting Up a SIMPLIS Simulation SIMPLIS analyses are setup using the sam
31. SIMetrix does retrieve the data for internal verilog nodes that interconnect VSXA instances in circuits where the Verilog digital signals are much higher speed than the analog signals such as this example there is a speed penalty for doing so For this reason there is a facility to disable this To demonstrate proceed as follows 1 Note the time that the last run took using command shell menu Simulator Show Statistics 2 Double click U1 the instance of clock v You should see a dialog box like this f J Edit Device Parameters x Voltage input logic 0 threshold Voltage input logic 1 threshold 2 3 Voltage output for logic 0 0 a Voltage output for logic 1 5 a Rise time 0 gt 1 100p Falltime 1 gt 0 100p a Input resistance 1T 5 Output resistance 100 3 Output Hi Z resistance 1T 3 Threshold time tolerance 100p a width 5k a V Disable output of non analog vectors E Disable module cache 3 Check the Disable output of non analog vectors box then click Ok 4 Rerun simulation and note the new simulation time You will probably see in the region of a 2 3 times speed up You may conclude from this that the facility to retrieve pue digital data is too expensive to be worthwhile but this will only be the case where the digital signal are considerable higher speed than the analog signals In this circuit the analog pulses are running at 10Hz whereas the digital pulses are running at 100kHz 10000 times as
32. To model this the leakage inductances for the centre windings could be coupled to each other using the mutual inductor method described in the next section Mutual Inductors You can specify coupling between any number of ideal inductors using the mutual inductor device There is no menu or schematic symbol for this It is defined by a line of text that must be added to the netlist See Manual Entry of Simulator Commands on page 57 The format for the mutual inductance line is Kxxxx inductor_1 inductor_2 coupling_factor Where inductor_1 Component reference of the first inductor to be coupled inductor_2 Component reference of the second inductor to be coupled coupling_factor Value between 0 and 1 which defines strength of coupling Note If more than 2 inductors are to be coupled there must be a K device to define every possible pair 133 User s Manual 134 Examples Couple L1 and L2 together K12 11 L2 0 98 Couple Li L2 and L3 K12 11 12 0 98 K23 L2 L3 0 98 K13 Ll L3 0 98 Resistors Capacitors and Inductors Resistors Resistors may be used in both SIMetrix and SIMPLIS modes Note that in SIMetrix mode a number of additional parameters may be specified These will not work with SIMPLIS and must not be specified if dual mode operation is required Select from PlacelPassives menu To edit value use F7 or select popup menu Edit Part menu as usual This will display the following dialog for res
33. a single fixed probe on an obvious point of interest then randomly probe to investigate the detailed behaviour of your circuit Fixed schematic probes are limited to single ended voltages and currents and differential voltages The random probing method allows you to plot anything you like including device power FFTs arbitrary expressions of simulation results and X Y plots such as Nyquist diagrams It is possible to set up fixed probes to plot arbitrary expressions of signals but this requires manually entering the underlying simulator command the GRAPH control There is no direct schematic support for this For details of the GRAPH control see the Command Reference chapter of the Simulator Reference Manual Fixed Probes There are several types of fixed probe Three of the commonly used probes are 1 Voltage Plots the voltage on a net 2 Current Plots the current in a device pin 3 Differential voltage Plots the voltage difference between two points They are simply schematic symbols with special properties When you place a fixed probe on the schematic the voltage or current at the point where you place the probe will be plotted each time you run the simulation The probes have a wide range of options which can be set by doubleclicking it These options are covered in detail in section Fixed Probes on page 223 There are more fixed probes available in addition to those described above See Fixed Probes on page
34. it is often useful to be able to plot some characteristic of each curve against the stepped value For example suppose you wished to investigate the load response of a power supply circuit and wanted to plot the fall in output voltage vs transient current load To do this you would set up a transient analysis to repeat a number of times with a varying load current See Multi step Analyses on page 200 to learn how to do this After the run is complete you can plot a complete set of curves take cursor measurements and manually produce a plot of voltage drop vs load current This is of course is quite a time consuming and error prone activity Fortunately SIMetrix has a means of automating this procedure A range of functions sometimes known as goal functions are available that perform a computation on a complete curve to create a single value By applying one or a combination of these functions on the results of a multi step analysis a curve of the goal function versus the stepped variable may be created This feature is especially useful for Monte Carlo analysis in which case you would most likely wish to plot a histogram Chapter 9 Graphs Probes and Data Analysis We start with an example and in fact it is a power supply whose load response we wish to investigate Example The following circuit is a model of a hybrid linear switching 5V PSU See Work Examples HybridPS U Svpsu_v1 sxsch 1 220 F Si
35. it will be considered as unknown Define Analog Waveform Only enabled if Analog waveform is specified in the Plot Type box Specifies the scaling values and units for analog waveforms Range Peak peak value used for display Offset Analog display offset A value of zero will result in an analog display centred about the x axis Units Select an appropriate unit from the drop down box Plotting an Arbitrary Expression If what you wish to plot is not in one of the probe menus SIMetrix has a facility to plot an arbitrary expression of node voltages or device currents This is accessed via one of the menus ProbelAdd Curve or Graphs and DatalAdd Curve Selecting one of these menus brings up the Define Curve dialog box shown below Chapter 9 Graphs Probes and Data Analysis Define Curve Sheet J Define Curve Available vectors gnd Curve label Expression Y X Available Vectors Define Cuve Axis Graph Options Axis Scales Axis Labels Left click on schematic to insert voltage shiftdeft for E XY Plot curent You can also work with existing graph curves just click the curve itself Separate multiple values with Signaltype All Wildcard filter text SS Gea Ge Enter arithmetic expression This can use operators and as well as the functions listed in Function Summary on page 317 To enter a node voltage click on a point on the
36. noi top will prevent all data except digital signals and the reference vector time frequency etc from being output With some or all data output inhibited using KEEP as described above you can add keep symbols to the schematic to select specific voltages or currents to be saved For information on the comprehensive features of KEEP please refer to the Simulator Reference Manual To Add a Voltage Keep to a Schematic 1 Select menu PlacelFrom Symbol Library 2 Select device Connections gt Keeps Voltage Keep 3 Place device on desired schematic net To Add a Current Keep to a Schematic 1 Select menu PlacelFrom Symbol Library Chapter 5 Components 2 Select device Connections Keeps Current Keep 3 Place device directly on a device pin Parameters and Expressions You can specify both device and model parameters using an arithmetic expression containing user defined variables The variables may be defined using the PARAM simulator control which must be placed in the netlist or globally in a script using the Let command A variable may also be swept using the parameter sweep mode for the swept analyses and stepped for multi step analyses Complete documentation on this subject can be found in the Simulator Devices chapter of the Simulator Reference Manual Below are brief details of how to use expressions with a schematic based design We explain this with an example Example M vout C1 alpha
37. support MinorGridPrintWidth Numeric Default 0 05 Options Print width in mm of dialog graph s minor grid ModelExtension Text Default Ib lib mod cir Options File extensions used for dialog model files MRUSize Numeric Default 4 Options Number of items in dialog File Reopen menu NewModelLifetime Numeric Default 30 Number of days that user installed models remain displayed in the Recently Added Models parts browser category NoEditPinNamesWarning Boolean Default false If true the warning given unsupported when using the Edit Pin Names button in the associate models dialog box is inhibited NoHierarchicalHighlighting Boolean Default false If set hierarchical schematic highlighting is disabled That is if you highlight some part of a hierarcical schematic only that schematic will be highlighted with no propagation to parent or child schematic NolnitXaxisLimits Boolean Default false Inverse of default value of the initxlims parameter of the GRAPH statement See Simulator Reference Manual for details Chapter 14 Sundry Topics Name Type Description User interface support NoKeys Boolean If on the default key Options definitions will be disabled dialog Note this will not take affect until the next session of SIMetrix NoMenu Boolean If on the default menu Options definitions will be disabled dialog and no menu bar will appear This will not take affect until the next session of SIMetrix
38. value and model properties These properties are usually specified for all symbols with the exception of hierarchical blocks which do not require a Value property If you are using the SIMetrix SIMPLIS product you will also be prompted to supply a value for the SIMULATOR property The following table describes the four standard properties 90 Chapter 4 Schematic Editor Property name Function Ref property Value property Model property Simulator property This is the component reference e g U1 R3 etc This would conventionally be a letter or letters followed by a question mark When you place the component on the schematic the question mark will be replaced automatically by a number that makes the reference unique If you don t specify a Model property see below the first letter of the reference is important as it defines the type of device This is explained in more detail below This is the device s value or model name including any additional parameters For a resistor this might be 12k for an op amp LM324 or for a bipolar transistor Q2N2222 The value property must be present on a symbol at the definition stage but its initial value is not important as it would usually be changed after the symbol is placed on a schematic This property usually has a value that is a single letter that specifies the type of device For sub circuits and hierarchical blocks this letter must be X For other types of
39. would be repeated 10 times with idx incrementing by one each time Note the semi colon at the end of the line This signifies that a new line must be created and is essential The end result of the above with NUM 10 RES 1k and CAP 1n is subckt ladder 1 11 gnd x1 1 2 gnd section X2 2 3 gnd section X3 3 4 gnd section X4 4 5 gnd section X5 5 6 gnd section X6 6 7 gnd section X7 7 8 gnd section X8 8 9 gnd section X9 9 10 gnd section X10 10 11 gnd section subckt section in out gnd R1 in out 1k C1 out gig in ends ends Although it is legal to nest REPEAT keywords we recommend avoiding doing so as it can lead to unexpected results You can always use subcircuit definitions to each multi dimensional repeats and these are usually easier to understand The above example has multiple lines These can be entered using the Edit Properties dialog box The best way to define multiple line templates is to first enter them in a text editor and then copy and paste to the Edit Properties dialog SERIES lt SERIES num lt line gt gt Creates a series combination of the device described in line For example lt series series lt lt ref gt lt nodelist gt VALUE gt gt Creates a series combination of components The number in series is determined by the property SERIES Note that the REF keyword returns the component reference appropriately modified by the MODEL property and appended with the sequence number If SERIES 5
40. 223 for details Fixed Voltage Probes You can place these on a schematic with the single hot key B or with one of the menus ProbelPlace Fixed Voltage Probe PlacelProbelVoltage Probe schematic popup Probe Voltage 59 User s Manual 60 Hint If you place the probe immediately on an existing schematic wire SIMetrix will try and deduce a meaningful name related to what it is connected to If you place the probe at an empty location its name will be a default e g PROBE1 NODE which won t be meaningful and you will probably wish to subsequently edit it Fixed Current Probes You can place these on a schematic with the single hot key U or with one of the menus ProbelPlace Fixed Current Probe PlacelProbelCurrent Probe schematic popup Probe Current Current probes must be placed directly over a component pin They will have no function if they are not and a warning message will be displayed Fixed Differential Voltage Probes These can be placed using one of the menus ProbelPlace Fixed Diff Voltage Probe PlacelProbelDifferential Voltage Probe Random Probes Most of the entries in the schematic s Probe menu are for random probing You can probe voltage current differential voltage device power dB phase Nyquist diagrams and much more You can also plot arbitrary expressions of any circuit signal and plot signals from earlier simulation runs Just a few of the possibilities to get you started
41. 4 Associates file extensions with the operating system Windows only 5 Sets up default window positions according to the system screen resolution only if preference settings not migrated in 3 6 Define default values for various fonts only if preference settings not migrated in 3 Auto Configuration Options Configuration settings are stored in a file called base sxprj See Configuration Settings on page 355 for details of where this file is located Auto configuration writes values to this file but will also read values from this file to decide how it will proceed In the usual sequence of events for installing and setting up SIMetrix this file will not actually exist when auto configuration occurs In this case auto configuration uses default values for the settings it tries to read However if you are a system administrator may wish to customise the way SIMetrix is configured when started by each user In this case you may manually create a base sxprj file or alternatively a common skeleton that SIMetrix will use to create this file Your base sxprj file can if desired be completely populated with all required settings and configured to disable auto configuration altogether Alternatively you can inhibit some of the auto configuration operations while allowing others to proceed normally There are five settings that control auto configuration These must be placed in the Options section of the base sxprj file The setti
42. 75 2N7002 PS 0 115 60 3 7 2n7269 26 200 0 1 BS107A PS 05 60 12 BS170 05 60 12 BS 170 05 60 12 BS170 PS 05 60 12 BS170P 05 60 12 BSCO22N03S_L150 30 18 BSCO32N03S_L1 50 30 18 BSCO42N03S_L1 50 30 35 BSCO52N03S_L1 50 30 43 A LESCORSNNYS 11 50 2 AG Filter Id all Vds max all Rds on all 2 Note that this is not the entire list of available parts of the desired type only parts for which a specification is available will be listed However there should be a representative range so that it should be possible to find a model suitable for initial development work To filter listed parts to include your desired spec use the drop down boxes at the bottom of the box in the Filter group Note that the upper end of each range is exclusive So for example 100 500 means everything from and including 100 up to but not including 500 3 Once you have selected your model click Ok to place in the usual way Chapter 5 Components Viewing and Editing Models All parts selected using the parts browser as described above are defined using a model located in the global model library You can view this model using the right click popup menu View Edit Model This will display something like the following dialog box Local model editable 12 7 3 5 91 90 SUBCKT TL072 REF4 12345 3 498E 12 15 00E 12 DX DX DX DX DX POLY 2 3 0 4 0 0 5 5 POLY S VB VC VE VLP VL
43. Change Text Already Entered Select the text then press F7 and enter the new text To Hide A Component Value Select popup menu item Hide Show Value Zoom Area Click the Zoom box toolbar button then drag mouse to zoom in on selected area Zoom Full Fit to Area Select popup ZoomIFull or press HOME key to fit whole schematic in current window size Zoom Out Click the Zoom out toolbar button or press F12 to zoom out one level You may also zoom out by holding down the control key and rolling the mouse scroll wheel backwards Zoom In Click the Zoom in toolbar button or shift F12 to zoom in one level You may also zoom out by holding down the control key and rolling the mouse scroll wheel forwards Panning The easiest way to pan the schematic is with the mouse scroll wheel Just rotate the wheel for vertical pan For horizontal pan hold down the shift key and rotate the wheel Chapter 4 Schematic Editor You may also use the scroll bars cursor keys and page up and down keys to pan schematic The left right up and down cursor keys pan the schematic one grid square in the relevant direction and the Page up Page down control left cursor control right cursor to pan the schematic 10 grid squares Notes on Property Text Position The SIMetrix schematic editor has been designed using a basic principle that it is better to move the component to make its property text visible rather than move the property That way the c
44. Data Analysis Signal Info If the signal being analysed is repetitive and the frequency of that signal is known exactly then a much better result can be obtained if it is specified here Check the Know fundamental frequency box then enter the frequency The Fourier spectrum will be calculated using an integral number of complete cycles of the fundamental frequency This substantially reduces spectral leakage Spectral leakage occurs because both the Fourier algorithms work on an assumption that the signal being analysed is a repetition of the analysed time interval from t 0o to t co If the analysed time interval does not contain a whole number of cycles of the fundamental frequency this will be a poor approximation and the spectrum will be in error In practice this problem is minimised by using a window function applied to the signal prior to the Fourier calculation but using a whole number of cycles reduces the problem further Note that the fundamental frequency is not necessarily the lowest frequency in the circuit but the largest frequency for which all frequencies in the circuit are integral harmonics For example if you had two sine wave generators of 1kHz and 1 1KHz the fundamental is 100Hz not 1kHz 1kHz is the tenth harmonic 1 1 KHz is the eleventh You should not specify a fundamental frequency for circuits that have self oscillating elements FFT Interpolation As explained above the FFT method must interpolate the signal pri
45. Define Symbol All references to symbol automatically updated If this is checked any changes you make to a symbol will automatically be applied to any instance of it in existing schematics whether they are open or not If it is not checked instances of the symbol will not be updated until the Update Symbols menu is selected in the schematic Copies of all symbols used by a schematic are stored locally within the schematic and that local version will only be updated if this box is checked See How Symbols are Stored on page 115 for further details Save to Library File Saves the symbol to the library file specified in the File box This would usually have a SXSLB extension Save to Component File Saves the symbol as a component to the file specified in the File box This would usually have the extension SXCMP Component files are used for hierarchical schematics and contain a schematic and a symbol representing it in the same file When you save a symbol to a component file only the symbol portion of it will be overwritten If it contains an embedded schematic that schematic will remain unchanged See Hierarchical Schematic Entry Save to Current Schematic Only The symbol will be saved to the currently selected schematic only and will not be available to other schematics File Library or component file name see above Press Browse to select a new file Creating a Symbol from a Script Creating a symbol fro
46. Editor 62 J Amplifier example Selected File Edit View Simulator Place Probe ProbeAC Noise Hierarchy Monte Carlo Verilog Schematic Windows and Sheets The schematic editor window is shown below It can display multiple sheets arranged like a notebook with tabs It is also possible to have multiple windows allowing schematic to be compared Creating Schematic Windows and Sheets To Open a new schematic window select menu FilelNew Schematic Window To Open a new schematic sheet select menu FilelNew Schematic Sheet This will create a new sheet in the selected window If no schematic is open one will be created Selecting Simulator Mode If you have SIMetrix SIMPLIS and you wish to enter a schematic for simulation with SIMPLIS you should select SIMPLIS simulator mode To do this select menu FilelSelect Simulator then select SIMPLIS Schematic Editor Window es e fata BERK r OSCIKKELT S680 8 PaXxcouez QAQQ 2 Amplifier example Probe Voltage Probe Current Display De Edit Add Pro Delete P es Move Text gt Edit Symbol NET V3_P SIMetrix Chapter 4 Schematic Editor Editing Operations IE TOI MBX CHH AQAl AYE i at Cut Wiring tool Detach Zoom in Duplicate Zoom out Undo Zoom box Save schematic Flip Close schematic Mirror Open schematic Rotate In the following notes references ar
47. For a more detailed discussion on accuracy see the chapter Convergence and Accuracy in the Simulator Reference Manual Frequency Response Calculations These must find the passband for their calculations Like rise and fall a histogram approach is used to find its approximate range and magnitude Further processing is performed to find its exact magnitude Note that the algorithms allow a certain amount of ripple in the passband which will work in most cases but will fail if this in excess of about 3dB Note that the frequency response measurements are general purpose and are required to account for a wide variety of responses including those with both high and low pass elements as well as responses with band pass ripple This requirement compromises accuracy in simpler cases So for example to calculate the 3dB point of a low pass response that extends to DC the OdB point is taken to be a point midway between the start frequency and the frequency at which roll off starts A better location would be the start frequency but this would be inaccurate if there was a high pass roll off at low frequencies Taking the middle point is a compromise which produces good but not necessarily perfect results in a wide range of cases To increase accuracy in the case described above start the analysis at a lower frequency this will lower the frequency at which the OdB reference is taken Plots from curves Two plots can be made directly from se
48. If the device being renamed is implemented as a subcircuit the rename utility will copy any symbol model association for that device with the new name Devices that are used locally i e within the model file itself will be excluded from the rename procedure These devices will not be renamed nor will they added to the list that is searched to identify duplicate names You can perform a test run which creates the log file but does not actually perform the renaming To do this type the command rename_libs_check Note that messages output to the log file and to the command shell will report the renaming of models but no renaming will actually take place 173 User s Manual Chapter 7 Analysis Modes Overview In this chapter we describe the various analysis modes available and how to set them up from the schematic editor There is more information on analysis modes including full details of the netlist commands to invoke them in the Command Reference chapter of the Simulator Reference Manual Most of the analyses can be setup using the Choose Analysis Dialog Box which is opened with the schematic menu SimulatorlChoose Analysis Ps Transient AC 0c Noise TF SOA Options Analysis Mode E Transient Transient parameters Fz Stop time S EAS DC Sweep Data output options F Noise Start data output 0 J WY Defaut E Transfer function PRINT step 20u
49. Manual 244 The names used for cross probing are stored in the schematic itself and are saved to the schematic file These netnames are not assigned until the netlist is created and this doesn t usually happen until a simulation is run A problem arises however if the schematic is not open If netnames have never been created then they won t be updated during the run as by default SIMetrix will not update a closed file This problem can be resolved by giving SIMetrix permission to update schematic files that are closed To do this type at the command line Set UpdateClosedSchematics This only needs to be done once Note that you can only do this with the full versions of SIMetrix This problem won t arise if you always run every schematic at least once while it is open If you do this the netnames will be updated and you will be promted to save the schematic before closing it Multiple Instances An issue arises in the situation where there are multiple instances of a block attached to the same schematic Consider the following top level circuit vi oi ut u2 VP VP 1 VINP_ VOUTF VIP VOUTH m i Pa Output VINN VOUTI VINN VOUTN x P3 v3 VN VN R2 Rt 1K o AC1 0 Pulse 0 10m0 5n 5n 500 1u Meg 1Meg E1 _4 a p alles v2 This has two instances of the block fastamp sxsch U1 and U2 Suppose yo
50. Materials The available models cover a range of ferrite and MPP core materials for inductors and transformers with any number of windings The complete simulation model based on a library core model is generated by the user interface according to the winding specification entered Placing and Specifying Components 1 Select the menu PlacelMagneticslSaturable Transformer Inductor You will see the following dialog box Chapter 5 Components J Define Saturable Transformer Inductor Configuration Define windings Primaries a Select winding Sec 1 1 w Pimaytums 100 S Secondaries 1 S Ratiotopimay1 1 amp Coupling factor 1 8 Define core Unts Ae 100 a Select core type 3 mm D N Manual entry cm Le 10 D inches Core material 3C81 l metres m a Primary inductance 125 664mH ap 35 8099mA C cca Hep 2 Specify the number of windings required for primary and secondary in the Configuration section If you just want a single inductor set primary turns to 1 and secondaries to 0 3 Specify turns ratios in the Define Windings section You can select the winding to define using the Select Winding drop down box then enter the required ratio to primary 1 in the edit box below it 4 Specify the number of turns for the primary and coupling factor The coupling factor is the same for all windings You can define different coupling factors for each winding by add
51. Noise AnalySis cceccccccscceeeseeeeeseeeeeneeeeeneneeseeeeeneseeees 189 Setting up an AC Noise analySis cceeeeee 189 Plotting Results of Noise Analysis 190 Ex IMple EE TE A AET 191 Example 2a 8 cacagecns itacaeteda pian ead 192 Real Time NoiSe ccceesccecceecseeeeeeseeeeeseeeseneesesneenees 193 Setting Up a Real Time Noise Analysis 193 Transfer FUNCtION rinine inao 195 Setting up a Transfer Function Analysis 195 Plotting Transfer Function Analysis Results 196 EXample c cei ene ets Maia aioe ate 196 Sensitivity eterna na aig neta 197 Setting up a Sensitivity Analysis 00 0 0 eee 197 Simulator Options ceeeeeeceeeeeeeeeeeeeeeeeeeeneeteeeeeeeenaees 198 Setting Simulator Options ceeeeeeeeeeeeeeeeeeeees 198 Multi step Analyses 000 eeseeeseeeeeeneeeeeeeeeseeteeneeeenaees 200 Setting up a Multi step Analysis ceeeeeeees 200 Example ds isis dyson ait a create nen e aeS 202 Example 2 e seson ate a aie ets 203 Safe Operating Area TeSting ccceeeeeteeteeeeeeerees 204 OVEIVIEW arenen ean steed 204 Defining Simple Limit Tests ecceeeeeeeeeeeees 204 Advanced SOA Limit Testing cccceeeeeeeenees 205 SIMPLIS Analysis Modes Transient Analysis cceeeeseeeeeseeeeeneeeeeneeeenaeeeeeneeeees 207 Setting up a Transient AnalySis cc sceeee 207 Periodic Operating Point POP esceeeceseeseeere
52. Power supply rejection ratio Simple ratio not dB Input Resistance Input differential resistance Chapter 5 Components Parameter Description Output Res Output resistance This interacts with the quiescent current The output resistance must satisfy Rout gt 0 0129 IQ Where IQ is the Quiescent current If the above is not satisfied there is a high risk that the model will not converge This limitation is a consequence of the way the output stage is implemented Quiescent Curr Supply current with no load This must satisfy the relation shown in Output Res above Headroom Pos Difference between positive supply voltage and maximum output voltage Headroom Neg Difference between minimum output voltage and negative supply rail Offset V Statistical For Monte Carlo analysis only Specifies the 1 sigma offset voltage tolerance Parameterised Opto coupler Implements a 2 in 2 out optically isolated coupler This is available from menu PlacelAnalog Functions Parameterised Opto coupler It is defined by just two parameters described in the following table Parameter Description Current transfer ratio Ratio between output current and input current Roll off frequency 30B point Parameterised Comparator Implements a simple differential comparator This is available from menu PlacelAnalog Functions Parameterised Comparator Its parameters are defined in the following table 141 User s Manual 142
53. Reference DefKey Define keyboard key Define fixed or popup menu item Delete menu item Write standard key definitions to file Create new group of simulation data from data file Read external logic compatibility tables Release memory used for simulation Create nodeset file to speed DC convergence Set option Displays the value of an expression Can be used to export data to a file in ASCII form Delete option DefKey Key_Label Command_string option_flag DefKey is used to define custom key strokes Key_Label Code to signify key to define See table below for list of possible labels All labels may be suffixed with one of the following SCHEM Key defined only when a schematic window is currently active GRAPH Key defined only when a graph window is currently active SHELL Key defined only when the command shell is currently active SYMBOL Key defined only when a symbol editor window is active If no suffix is provided the key definition will be active in all 309 User s Manual 310 windows Command_string A command line command or commands to be executed when the specified key is pressed Multiple commands must be separated by semi colons Unless the command string has no spaces it must wholly enclosed in double quotation marks option_flag Either 0 or 5 Specifies the manner in which the command is executed These are as follows 0 Default Command is echoed and executed
54. Returns sequence number IF lt IF test action1 action2 gt If test resolves to a non zero value action will be substituted otherwise action2 will be substituted Typically test would be an expression enclosed in curly braces and For example the following implements in a somewhat complex manner a series connection of resistors This should actually all be on one line lt REPEAT line SERIES lt REFS R line lt if line 1 lt lt NODE 1 gt gt SREF line gt lt if line SSERIES lt lt NODE 2 gt gt S REF S linetl gt VALUE gt gt Chapter 4 Schematic Editor Note that usually each action should be enclosed with lt and gt They can be omitted if the action does not contain any keywords If in doubt put them in IFD lt IFD propname action1 action2 gt If propname is present and not blank action will be substituted otherwise action2 will be substituted Example lt ifd value lt value gt 1 gt In the above if the property value is present it will be substituted otherwise the value T will be substituted JOIN lt JOIN prop_name index gt This can only be used with instances of symbols with one and only one pin Returns the value of prop_name on an instance attached directly to the single pin of the device For example in the following R1 P 1K R1 lt JOIN REF gt on the probe R1 P would return R1 as this is the value of the REF property of the resisto
55. SIMetrix but you can obtain others from device manufacturers usually at no cost and other model vendors You can also create them yourself using a text editor Many vendor libraries may be downloaded from the Internet Our World Wide Web site carries a page with links to vendor sites URL is http www simetrix co uk app models htm This section explains how to use install and manage parts libraries Important The library and parts management systems described in this chapter work with discrete devices defined using subcircuits and MODEL statements It currently does not support process corner selection and process binning used by many models supplied by integrated circuit process foundries See Using Schematic Editor for CMOS IC Design on page 112 for details on how to handle such libraries Using Parts Browser 162 The parts browser provides a convenient method of selecting a component Parts are arranged in categories to allow for rapid searching To open parts browser select schematic menu PlacelFrom Model Library All devices for which models have been installed will be displayed and listed under an appropriate category If you can t find a device under the expected category select the All Devices category Every single device currently installed will be displayed here Note for large libraries you may have to wait a second or two to see the list of devices when selecting this category If you have instal
56. Select DC tab at the top Enter parameters as described in the following sections Chapter 7 Analysis Modes Sweep Parameters Start value Stop value Defines sweep range stop and start values Points per decade Number of points Defines sweep range The number of points of the sweep is defined per decade for a decade sweep For a linear sweep you must enter the total number of points Device Parameter Model Name The device name for a device sweep parameter name for a parameter sweep or the model name for a model parameter sweep may be entered here It may also be entered in the sweep mode dialog opened by pressing Define Define Sets up desired sweep mode See Setting up a Swept Analysis on page 185 Monte Carlo and Multi step Analysis See page 200 See Also DC in Simulator Reference Manual Example The following is the result of a DC sweep of V3 in the example circuit shown on page 184 with restail set to 1K Analysis parameters were as follows Sweep mode Device V3 Sweep range 0 1 to 0 1 linear sweep with 50 points DC transfer function of simple diff amp Output mV 100 80 60 40 20 0 20 40 60 80 100 V3 mV 20mV div 187 User s Manual AC Sweep 188 An AC analysis calculates the small signal response of a circuit to any number of user defined inputs The small signal response is computed by treating the circuit as linear
57. Show current in source inverter pin J Place N JFET K Place P JFET L Place ideal inductor Chapter 10 The Command Shell Key Unshifted Shift Control Shift Control M Place NMOS Place bias Update bias transistor marker values N Place NPN Place 2 input Show voltage at transistor NAND node O Place Op amp Place 2 input OR P Place PNP Place digital Show pinname transistor pulse at cursor Q Repeat arc symbol editor R Place resistor Place 2 input Repeat last NOR probe S Place switch Show netname at cursor T Place Switch window transmission line U Place fixed current probe V Place voltage Place digital Paste source VCC W Place waveform Select Window generator X Place ideal Place 2 input Cut transformer XOR Y Place terminal Z Place zener Undo diode schematic 2 Place NMOS 4 term transistor 3 Place PMOS 4 term transistor 4 Place resistor z shape 5 6 7 8 9 305 User s Manual Key Unshifted Shift Control Alt F1 Help F2 Step script Pause script Resume script F3 Start wire schem More analysis functions graph F4 Probe Voltage Quit immediate Close window F5 Rotate schem symbol Cursor to previous Cursor to next peak peak graph graph F6 Mirror schem symbol Flip schem Cursor to next trough symbol editor graph Cursor to previous trough graph F7 Edit Part schem Edit literal value Move value Edit Ref cursor to next peak schem Ref MOS graph cursor to previous value
58. The left button will complete a segment and terminate the operation while the right button will terminate without completing the current segment 3 Enter Draw Segment Mode temporarily by pressing F3 4 Double click the left button to start a new segment Drawing Arcs Circles and Ellipses The basic method of drawing each of the curved elements is the same for each case Before drawing starts you must define the start finish angle and for ellipses the ratio of height to width The drawing operation itself defines the start and finish points For full circles and ellipses the start and finish points are on opposite sides Dedicated menus are supplied for starting a full circle half circle and quarter circle For everything else use ArcslEllipse Arc Chapter 4 Schematic Editor When you have initiated the operation the cursor will change to a shape showing a pencil with a small circle You can now draw the curved segment by dragging the mouse with the left key When you release the mouse button the operation will be complete and the mouse mode will revert to normal select mode It is easier to demonstrate than explain You may wish to experiment with arc circle ellipse drawing to gain a feel of how the system operates You will note that full circles are displayed with a small filled square on opposite sides These are the select points You can pick either one and drag it to resize the circle Placing and Defining Pins Pla
59. User s Manual 64 To Change Value or Device Type for a Component First select it then select schematic popup Edit Part or press F7 Alternatively you can just double click the device A dialog box appropriate for the type of component will be displayed For devices requiring a model name a list of available types will appear To Rotate Mirror or Flip a Component Click the Rotate toolbar button or press key F5 to rotate a component This operation can be performed while a component is being placed or while a block is being moved or copied see below You can also select a component or block then click the Rotate button or press the F5 key to rotate in situ To mirror a component or block through the y axis click the Mirror toolbar button or press the F6 key To flip a component or block mirror about x axis click the Flip toolbar button or press shift F6 Wiring See Wiring on page 67 below Deleting Wires Select the wire by placing cursor over it clicking left button Click the Cut toolbar button or press delete key Disconnecting Wires Press the shift key then select area enclosing the wire or wires to be deleted Press delete button To Move a Single Component Place the cursor within it and then drag it using the left mouse key You can rotate flip mirror the component see above while doing so To Move More Than One Item Select items as described above Place cursor within any of the selected
60. X1 X matches any name that starts with an X and with a for the third letter q10 c matches any name ending with q10 c i e the current into any transistor called q10 U1 vout matches any name ending with U1 C11 i e any node called vout in a subcircuit with reference U1 Curve Label Enter text string to label curve Axis Graph Options Sheet Allows you to control where the curve for the probed signal will be placed Define Curve Axis Graph Options Axis Scales Axis Labels Graph options Addto selected New graph sheet New graph window Digital SS Ge Axis Type Select an appropriate axis type Note that you can move a curve to a new axis or grid after it has been plotted See Moving Curves to Different Axis or Grid on page 249 241 User s Manual 242 Auto select Select an appropriate axis automatically See AutoAxis Feature on page 248 Use Selected Use currently selected y axis Use New Y axis Create a new y axis alongside main one Use New Grid Create a new grid stacked on top of main axis Digital Axis Create a new digital axis Digital axes are placed at the top of the window and are stacked Each one may only take a single curve As their name suggests they are intended for digital traces but can be used for analog signals if required Graph Options Add To Selected Add curve to currently selected and displayed graph sheet Ne
61. a graph that has never been saved before To update a saved graph use command shell menu FilelGraphlSave or graph menu FilelSave Restoring Select command shell menu FilelGraphlOpen or if a graph window already exists graph menu FilelOpen Viewing DC Operating Point Results 278 Schematic Annotation You can annotate the schematic with the results of a DC operating point analysis This requires special markers to be placed on the schematic You can instruct SIMetrix to place markers at every node or you can place them manually To place a voltage marker manually use the schematic popup Bias Annotation Place Marker or use control M The text displaying the value will be placed on the sharp side of the marker which to start with points up If you are placing the marker on a vertical wire you might wish the text to be on one side To do this rotate the marker before placing by pressing the rotate toolbar button or the F5 key To place a current marker use the menu PlacelBias Annotation Place Current Marker To place markers as all nodes select Bias AnnotationlAuto Place Markers This does however clutter up the schematic and you may prefer to place them manually To display the values select Bias Annotation Update Values These values are automatically updated after each simulation run The menu Bias Annotation Delete Markers deletes all the markers and Bias AnnotationlHide Values removes the text but leaves the markers in place
62. alpha 4 c2 The above circuit is that of a two pole low pass filter C1 is fixed and R1 R2 The design equations are R1 R2 2 2 pi f0 Cl1 alpha C2 C1 alpha alpha 4 where freq is the cut off frequency and alpha is the damping factor Expressions for device values must be entered enclosed in curly braces and To enter expressions for components we recommend that you use shift F7 not F7 as for normal value editing and remember the curly braces shift F7 provide literal editing of a devices value and bypasses the intelligent system employed by F7 and the Edit Part menu Before running the above circuit you must assign values to the variables This can be done by one of three methods 1 With the PARAM control placed in the netlist 2 With Let command from the command line or from a script If using a script you must prefix the parameter names with global 159 User s Manual 160 3 By sweeping the value using the parameter mode of a swept analysis page 182 or multi step analysis page 200 Expressions for device values must be entered enclosed in curly braces and Suppose we wish a kHz roll off for the above filter Using the PARAM control add these lines to the netlist using the F11 window see Manual Entry of Simulator Commands on page 57 PARAM f0 1k PARAM alpha 1 PARAM C1 10n Using the Let command you would type Let f0 1k Let alpha 1 Let C1 10n If you the
63. already associated These are devices for which SPICE models are known to be available from some third party source This database is in the file ALL CAT which you will find in support directory under Windows and in the share directory under Linux The information you enter in the associate models dialog is stored in a file called USER_v2 CAT which you will find in the application data directory see Application Data Directory on page 355 You will also not need to perform the above procedure for many 2 and 3 terminal semiconductor parts even if they are not listed in the ALL CAT database SIMetrix runs a series of simulations on these models and attempts to determine what the device type is from their results If successful the association step demonstrated above will be skipped Finally there is a method of embedding association information within the model itself and such models will not require manual association The embedding method is described in Embedded Association on page 169 41 User s Manual Chapter 3 Getting Started Overview This chapter describes the basic operation of SIMetrix and is aimed primarily at novice users The basic steps to simulate a circuit are as follows 1 Enter the circuit using the schematic editor See page 42 below 2 Add signal sources if relevant to your circuit See page 46 below 3 Specify analysis This includes what type of analysis and over what lim
64. an example In tutorial 1 the signal marked with the Amplifier Output probe is actually called Q3_E The latest run group is called tran4 We want to plot the output subtracted from the output for the previous run The previous run will be tran3 So we enter in the y expression box tran4 q3_e tran3 q3_e For more details on data groups please refer to the Script Reference Manual This is available as a PDF file on the install CD see Install CD on page 16 and may also be downloaded from our web site Chapter 9 Graphs Probes and Data Analysis Curve Operations Selecting Curves A File Edit Cursors Annotate Curves Axes View Measure Plot PAAA S MANGE EB AYERS m A s1 v1 m A 3 Y2 Click here to select tan5S1P Y1 this curve L3 P A o S1 P V o N e D a maa el a Ee N a _ gt lt VP t 202 204 206 208 24 Time kSecs 20Secs div x 1 95758kSecs y 20 0764A Deleting Curves To delete a curve or curves select it or them then press the Erase selected curves button Any axes or grids other than the Main axis left empty by this operation will also be deleted Hiding and Showing Curves A curve may be hidden without it actually being deleted This is sometimes useful when there are many curves on a graph but the detail of one you wish to see is hidden by others In this instance you can temporarily remove the curves fro
65. an output voltage you may also access the current flowing through it using I out In the example above the expression shown V vina vinb I iin multiplies a voltage and current together This could be used to monitor the power in a two terminal device as shown in the following schematic 147 User s Manual 148 Pulse O 1 0 1m 1m FAM V vina vinb iin ARBI1 y in OUTP ARB1 OUTP vina OUN vinb r T In the above ARB 1 is the device created from the Non linear Transfer Function menu ARB1 OUTP will carry a voltage equal to the power dissipation in R1 Expression The expression may use arithmetic operators and functions as defined is the Simulator Reference Manual Chapter 3 Using Expressions Verilog A Implementation If you have a VX license you may select the Compile to binary using Verilog A option This will build a definition of the device using the Verilog A language then compile it to a binary DLL This process takes place when you run the simulation The benefit of using Verilog A is that there is a wider range of functions available and for complex definitions there will also be a performance benefit Refer to the Verilog A Manual for details of available functions Laplace Transfer Function Selecting the menu PlacelAnalog BehaviourallLaplace Transfer Function brings up the following dialog Chapter 5 Components Definition
66. analysis modes such as noise and transfer function are not included because these don t support schematic cross probing of current or voltage If the schematic is in SIMPLIS mode SIMetrix SIMPLIS product only the analysis POP will show instead of DC Sweep Enter a string to control the grid display order The value is arbitrary and will not be displayed To force the curve to be placed above other curves that don t use this value prefix the name with The l character has a low ASCII value Conversely use to force curve to be displayed after other curves If Use default is checked the colour will be chosen automatically in a manner that tries to minimise duplicate colours on the same graph Alternatively uncheck this box then press Edit to select a colour of your choice In this case the trace will always have the same colour Plot on completion only If checked the curve will not be created until the analysis is finished Otherwise they will be updated at an interval specified in the Options dialog FilelOptionsIGeneral see Options on page 357 Chapter 9 Graphs Probes and Data Analysis Axis Scales Sheet fa J Edit Probe m Probe Options Axis Scales Axis Labels l X Axis Lin Log Auto Log Auto Nochange No change Auto scale Auto scale Defined Defined Min Z Min Max 1 Max 1 Gea Ge X Axis Y Axis X and Y axis parameters Lin Log Auto Specify whether
67. and it is also possible to create new toolbars and buttons Full details are provided in the Script Reference Manual Chapter 7 Message Window The message window is the window in the command shell below the command line The majority of messages including errors and warnings are displayed here The window can be scrolled vertically with the scroll bar 303 User s Manual You can copy a line of text from the message window to the command line by placing the cursor on the line and either double clicking the left mouse key or pressing the Insert key Up to 2000 lines of messages will be retained for viewing at any time Menu Reference For complete documentation on menu system please refer to the on line help The menu reference topic can be viewed by selecting the menu HelplMenu Reference Keyboard 304 The following keys definitions are built in They can all be redefined using the DefKey command see DefKey on page 309 or short cut with DefMenu command Key Unshifted Shift Control Shift Control A Place 2 input Ascend one level AND schem B Place fixed voltage probe C Place capacitor Copy schem Copy to clipboard graph D Place diode Place D type flip Duplicate flop schem E Place voltage Descend into controlled block schem voltage source F Place current controlled current source G Place ground Place digital Browse Parts ground H Place module port l Place current Place digital
68. and to resolve convergence problems In addition SIMetrix includes schematic entry and waveform analysis features that owe nothing to the original SPICE program Features Closely coupled direct matrix analog and event driven digital simulator Fully integrated hierarchical schematic editor simulator and graphical post processor Chapter 1 Introduction Superior convergence for both DC and transient analyses Pseudo transient analysis algorithm solves difficult operating points while enhanced transient analysis algorithm virtually eliminates transient analysis failures Advanced swept analyses for AC DC Noise and transfer function 6 different modes available Real time noise analysis allowing noise simulation of oscillators and sampled data systems Support for IC design models such as BSIM3 4 VBIC and Hicum Cross probing of voltage current and device power from schematic Current and power available for sub circuits Monte Carlo analysis including comprehensive tolerance specification features Full featured scripting language allowing customised waveform analysis and automated simulation Verilog A Analog Hardware Description Language Mixed signal simulation using Verilog HDL Functional modelling with arbitrary non linear source and arbitrary linear s domain transfer function Arbitrary logic block for definition of any digital device using descriptive language Supports synchronous asynch
69. are explained below For a full reference see Random Probes on page 228 Random Voltage Probing 1 Select the schematic menu item Probel Voltage 2 Using the mouse place the cursor over the point on the circuit you wish to plot 3 Press the left mouse button A graph of the voltage at that point will be created The new curve will be added to any existing graph if the X axis has the same units Otherwise a new graph sheet will be created Random Voltage Probing On New Graph Sheet 1 Select the schematic menu item ProbelVoltage New Graph Sheet 2 Using the mouse place the cursor over the point on the circuit you wish to plot 3 Press the left mouse button A graph of the voltage at that point will be created A new graph sheet will be created for it unconditionally Random Current Probing 1 Select the schematic menu item ProbelCurrent Chapter 3 Getting Started 2 Using the mouse place the cursor at the device pin whose current you wish to plot 3 Press the left mouse button A graph of the current at that point will be created The new curve will be added to any existing graph if the X axis has the same units Otherwise a new graph sheet will be created Random Current Probing On New Graph Sheet 1 Select the schematic menu item ProbelCurrent in Device Pin New Graph Sheet 2 Using the mouse place the cursor at the device pin whose current you wish to plot 3 Press the left mouse button
70. be output to the list file but the simulation will continue normally Ignore no warning or error will be raised and the simulation will continue normally Echo all messages Tf set all script lines will be displayed in the message window This will result in a great deal of output and will slow down the whole program operation Only set this if you are debugging your own scripts Don t abort scripts on error Normally scripts abort if an error is detected Check this box to disable this behaviour The built in key definitions can be disabled allowing you to define your own Refer to the DefKey command in the Script Reference Manual Disable standard key definitions Disable key definitions Note that many of the key assignments are defined as menu short cuts their name appears in the menu text These are not disabled by this option Does not take effect until you restart SIMetrix Locations in your files system of various files and folders needed for correct operation of SIMetrix Built in Scripts This is the first location that SIMetrix searches for scripts Much of the user interface is implemented with scripts and these are all internal to the program These can be overridden by placing scripts of the same name at this location This allows modification of the UI Changing this setting has no effect until you restart SIMetrix 361 User s Manual 362 Editor Text editor called by EditFile command as used by a numb
71. box Next check Select Core Type Select EFD10 3F3 A25 This is part number for a Ferroxcube ferrite core This is what you should have 35 User s Manual J De saturable Transformer Inducto Configuration Define windings Primaries 1 m Select winding gt Primarytums 34 Secondaries 0 S Ratiotopimay1 1 Coupling factor 1 Define core Select a be ie D velect core WPS A Te em Manual entry SS cm ie a z inches Core material 3F3 metres Ye I6 Primary inductance 29 127uH Cancel Saturation cuvet 3 78206A Mem eet Click Ok to close the dialog box Place the inductor in the same place as before Run a new simulation Select the graph sheet that displayed the inductor current by clicking on its tab at the top of the graph window Now select schematic menu ProbelCurrent in Device Pin and left click on the left hand inductor pin You will notice the peak current is now in excess of 45A This is of course because the inductor is saturating You can also measure the peak power over 1 cycle 1 36 Select the graph sheet with the power plot then select ProbelPower In Device Zoom back to see the full graph using the button Zoom in on the peak power Position the cursors to span a full cycle The cursors are currently tracking the first power curve This doesn t actually matter here as we are only interested in the x axis values If you want to make the cursors track the
72. bus has 8 wires as defined in the child schematic To begin with the label will be 0 7 and will therefore connect to bus wire 0 to 7 If you change the offset to for example 4 the label will change to 4 11 meaning that the connection will now be made to wires 4 to 11 Changing a Non bus Connection to a Bus Connection 1 In the child schematic change the Module Port to a Module Bus Port and edit as appropriate 2 In the parent schematic select the block then menu HierarchylUpdate Bus Connections This will update the schematic to show the bus connection on the hierarchical block Changing the Size of a Bus Connection 1 In the child schematic select the appropriate Module Bus Port 2 Press F7 and enter the new size as required 3 In the parent schematic select the block then menu HierarchylUpdate Bus Connections Global Nets You can access any net at the top level of a hierarchy using a terminal symbol and prefixing the name with For example suppose you have a net at the top level called VCC You can access this net at any level of the hierarchy without having to pass the connection by connecting a terminal symbol PlacelConnectorslTerminal and then assigning it the name VCC Global Pins Supposing you have two instances of a hierarchical block which you wish to connect to different supply rails To do this you would need to connect the supplies say VCC to pins at the top level with explicit i e non globa
73. c config_location f features schematic_file Path of a schematic file usually with extension sxsch This file will be opened immediately s startup_script Name of script file or command that will be executed immediately after SIMetrix starts fi If specified the schematic_file or and startup_script will be opened run in an existing instance of SIMetrix if there is one That is a new instance will not be started unless none are already running n Now a legacy option Originally inhibited the display of the splash screen The splash screen was removed from version 5 1 so this option now does nothing c config_location This identifies where SIMetrix stores its configuration settings config_location should be of the form PATH file_pathname file_pathname identifies the location of a file to store the configuration settings You may use any of the system constants defined in Definition on page 352 in this definition of file_pathname E g 7EXEPATH for the executable directory 354 Chapter 14 Sundry Topics See Configuration Settings below for details of configuration settings The REG syntax available with earlier versions is no longer supported f features Specifies which features are enabled Please refer to http www simetrix co uk app LicenseManager MiscellaneousTopics htm see Mixed Feature Licenses heading Using startup ini Start up parameters can also be specified in a file calle
74. caption for example is a symbol that consists purely of properties Segments These make up the visible body of the symbol They include straight line segments and arc segments Pins These define electrical connections to the device Properties Properties have a name and a value and are used to define the behaviour of the device represented by the symbol They can also be used for annotation for example a label or a caption Creating a New Symbol Select the command shell menu FilelSymbol EditorlNew Symbol This will open a symbol editor window as shown above Now create the elements of the symbol as described above Details are provided in the following sections Editing an Existing Symbol Select the command shell menu File Symbol EditorlSymbol Manager and select the symbol you wish to edit See Symbol Library Manager on page 107 for details If you wish to edit a symbol that is placed on an open schematic select the symbol on the schematic then choose popup menu Edit Symbol Drawing Straight Line Segments Drawing straight line segments in the symbol editor is very similar to drawing wires in the schematic editor You can do one of the following 1 Select Draw Segment Mode by clicking the Draw segment tool button You can now draw segments using the left and right mouse buttons Press the button again to revert to normal mode 2 Ifyou have a three button mouse the middle button will start a new segment
75. commonly set to LiveMode meaning that the menu will always be enabled except when an operation is already in progress For full details see DefMenu description in the Script Reference Manual Chapter 11 Command and Function Reference OpenGroup OpenGroup text overwrite filename Reads in a data file There are more options available in addition to the above Please refer to the Script Reference Manual for further information text If specified data file is assumed to be in text format Otherwise the file is input as a SIMetrix binary data file as saved by the SaveGroup command See Data Import and Export on page 296 for details of text format overwrite Forces existing group of the same name to be overwritten If not specified the group being read in will be renamed if a group of the same name already exists filename Name of file to be input OpenGroup creates a new Group If text is not specified then the name of the group will be that with which it was stored provided the name does not conflict with an existing group If there is a conflict the name will be modified to be unique If text is specified then the group will be named textn where n is chosen to make the name unique ReadLogicCompatibility ReadLogicCompatibility filename Reads a file to define the compatibility relationship between logic families For an example of a compatibility table see the file COMPAT TXT which you will find in the
76. device refer to the table in Summary of Simulator Devices on page 115 If this property is not present the first letter of the ref property will be used to identify the device For information only The value of this property and a symbol are prefixed to the ref property to obtain the first word of the device line in the netlist hence complying with SPICE syntax This won t be done if the first letter of the Ref property is already the same as the value of the model property as this would be unnecessary This is only required for the SIMetrix SIMPLIS product It declares which simulator the symbol is compatible with This is only for the purpose of advising the user if a component may not work with a particular simulator It does not affect the functionality of that component for any simulator This property can have one of three values SlMetrix Symbol compatible with SiMetrix simulator only SIMPLIS Symbol compatible with the SIMPLIS simulator only Dual Symbol compatible with both SIMetrix and SIMPLIS User s Manual 92 Editing a Property To edit a property select it then press F7 or select popup menu Edit Property Pin Atrc This will open a dialog box very similar to the one described above but without the option to enter a property name Make the appropriate changes then press OK Saving Symbols To save the current symbol select menu FilelSave The following dialog will be displayed J Save
77. equivalent menu is selected Script to be called when the shift up key is pressed This is to increment a component s value Currently used for potentiometers and some passive devices As incscript but for shift down to decrement a device This property is automatically allocated to every instance and always has a unique value Because it is automatically added it is the only property that every schematic component is guaranteed to possess This property is protected and therefore cannot be edited Determines simulator compatibility See Adding Standard Properties on page 90 Template Property This is the subject of its own section See below Chapter 4 Schematic Editor Editing Properties in a Schematic Unprotected properties of a symbol placed on a schematic may be edited using the popup menu Edit Properties This first opens a dialog listing all properties owned by the device After selecting the property to edit a dialog box similar to the box described in Defining Properties on page 87 If the property you select is protected the dialog box will still open but you will not be able to change any of the settings Restoring Properties This is a method of restoring an instance s properties to the values and attributes of the original symbol This is especially useful in situations where a symbol has been edited to for example add a new property and you wish that new property to be included on existing instances
78. expressed as W and L respectively You can use similar expressions for any other parameter As an alternative you can define AS AD etc as a parameter expression in a sub circuit See Subcircuits on page 153 for more details Editing the MOS Symbols You may wish to create your own MOS symbols for each process you use We suggest that you always make a copy of the standard symbols and save them with a new name in your own symbol library Once you have your copied version you can edit it to suit your IC process In most applications you will probably only need to edit the VALUE property See next paragraph Editing VALUE property The VALUE property defines the model name and all the device s parameters except length width and the multiplier M The standard VALUE property defines just the model name and this defaults to N1 for NMOS devices and P1 for PMOS devices You should edit these to match the model name used in your process In addition as described in Automatic Area and Perimeter Calculation above you can append the VALUE property with other parameters such as AD AS etc and define these as expressions relating width using W or and length using L To Edit the Default Values of L and W Edit the L and W properties as appropriate To Edit the Hidden Node for 3 Terminal Devices The hidden bulk node for three terminal devices is defined by the BULKNODE property This defaults to VSS for NMOS de
79. fall time scripts for this purpose Users should note that using this function applied to raw transient analysis data will produce misleading results as the simulation values are unevenly spaced If you apply this function to simulation data you must either specify that the simulator outputs at fixed intervals select the Output at interval option in the Choose Analysis dialog box or you must interpolate the results using the Interp function see page 324 Iff real any any Test Result if test TRUE Result if test FALSE Arg2 and Arg3 must both be the same type If the first argument evaluates to TRUE i e non zero the function will return the value of argument 2 Otherwise it will return the value of argument 3 Note that the type of arguments 2 and 3 must both be the same No implicit type conversion will be performed on these arguments Chapter 11 Command and Function Reference IIR real real real Vector to be filtered Coefficients Initial conditions default zero Performs Infinite Impulse Response digital filtering on supplied vector This function performs the operation Yn Xn Co Yn 1 C1 Yn 2 C2 Where x is the input vector argument 1 c is the coefficient vector argument 2 y is the result returned value The third argument provide the history of y i e yY y etc as required The operation of this function and also the FIR function is simple but its application can be
80. following r3_value r3_value is an arbitrary parameter name You could also use R3 2 Select menu SimulatorlSelect Multi step 3 Enter r3_value for Parameter Name and set Start value to 20 Stop value to 100 and Number of steps to 3 This should be what you see J Define SIMPLIS Multi Step Analysis Sweep mode Step parameters Parameter Start value 30 a Monte Cario Stop value 100 a Number of 3 m Parameters steps Parameter value Decade Group curves name Linear Monte Carlo Seed List Enable aT a GS Ge oe 4 Press Run The analysis will be repeated three times for values of r3_value of 20 60 and 100 The resistor value R3 is defined in terms of r3_value so in effect we are stepping R3 through that range Chapter 8 SIMPLIS Analysis Modes In most cases you will probably want to step just one component in a similar manner as described above But you can also use the parameter value to define any number of component or model values If you now run a normal single analysis you will find that SIMPLIS reports an error as it is unable to resolve the value for R3 This can be overcome by specifying the value using a VAR control Add this line VAR r3_value 100 to the F11 window This line defines the value of R3 when a normal single step analysis is run Options The above example illustrates a linear multi step parameter run You can also define a decade logarithmic run and als
81. for an option that has not been Set and which is not internal and error will be displayed Function Summary The following table lists a small selection of the functions available with SIMetrix Full documentation for these is provided in the Script Reference Manual This is available as a PDF file on the install CD see Install CD on page 16 and may also be downloaded from our web site Function name Description Page no abs real complex Absolute value 319 arg real complex phase result wraps at 180 180 319 degrees arg_rad real complex phase radians Result wraps at 320 pi pi radians atan real complex Arc tangent 320 cos real complex Cosine 320 db real complex dB x 20 log10 mag x 320 diff real Return derivative of argument 320 exp real complex Exponential 320 fft real string Fast Fourier Transform 320 FIR real real real Finite Impulse Response digital 321 filter Floor real Returns argument truncated to 321 next lowest integer GroupDelay real complex Returns group delay of argument 322 Histogram real real Returns histogram of argument 322 Iff real any any Returns a specified value 322 depending on the outcome of a test 317 User s Manual Function name Description Page no llR real real real Infinite Impulse Response digital 323 filter im imag real complex Return imaginary part of 324 argument integ real Returns integral of argument 324 Interp real real
82. for more details Options Overview Chapter 14 Sundry Topics There are a number of options affecting all aspects of SIMetrix Many of these may be viewed and adjusted using the Options dialog box others can only be accessed from the command line using the Set and UnSet commands Using the Options Dialog This is invoked with the menu FilelOptions General This brings up the following Schematic Graph Printing Graph Probe Data Analysis Model Library Shell Scripts File gt Undo level Double click mode Placement E a E Defaut Classic Repeat for all symbols Edit selected n Most Re Files component Repeat for toolbar symbols only 4 a 7 Default Never repeat Bias Annotation Precision Edit Mode Wiring 6 S T Defaut Classic Enable smart wiring gt Grow wire 7 ieee ene itn iia See Help for info Allow route through connected 0 I 7 Default Orthogonal Grid Set to Oto disable Hide grid Property editing Initial Simulator Hierarchy Highlighting Enable GUI SiMetrx property edits 7 Disabled SIMPLIS Schematic Sheet Undo Level Most Recent Files Number of levels of schematic undo See Creating a Schematic on page 42 Controls how many recently used files are displayed in the FilelReopen menu Bias Annotation Precision Controls the precision of the schematic voltage and current bias ann
83. for plotting To do this you must specify the wait switch for the Shell command to force SIMetrix to wait until the external application has finished E g Shell wait procdata exe will launch the program procdata exe and will not return until procdata exe has closed Data Files Text Format SIMetrix has the ability to read in data in text form using the OpenGroup command page 313 This makes it possible to use SIMetrix to graph data generated by other applications such as a spreadsheet This can be useful to compare simulated and measured results There are two alternative formats The first is simply a series of values separated by white space This will be read in as a single vector with a reference equal to its index The second format is as follows A text data file may contain any number of blocks Each block has a header followed by a list of datapoints The header and each datapoint must be on one line The header is of the form reference_nameydatal_name ydata2_name Each datapoint must be of the form reference_valueydatal_value ydata2_value The number of entries in each datapoint must correspond to the number of entries in the header The reference is the x data e g time or frequency Example Time Voltagel Voltage2 0 4 5396 4 6916 le 09 4 5397 4 6917 2e 09 4 5398 4 6917 4e 09 4 54 4 6917 8e 09 4 5408 4 6911 1 6e 08 4 5439 4 688 3 2e 08 4 5555 4 6766 6 4e 08 4 5909 4 641 le 07 4 6404 4 590
84. graph Moving Place cursor inside the box and drag to new location Resizing You can alter the maximum height of the box by placing the mouse cursor on it s bottom edge and dragging The text in the box will automatically reposition to comply with the new maximum height Editing Properties Double click on the box or select then menu AnnotatelEdit Selected Object The following dialog will be opened J Edit Legend Box E Properties Label Background Colour DefaultLabel DefaultLabel DefaultLabel Font items enclosed with are symbolic values See help for details So eee Label Lists each label in the box These are usually DefaultLabel which resolves to the name of the referenced curve To edit double click on the desired item You can also enter the symbols X1 and Y1 which represent the x and y co ordinates of the marker respectively These can be combined with other text in any suitable manner For example Voltage X1 S Y1 might resolve to something like Voltage at 10u 2 345 The values of X1 and Y1 will automatically update if you move the marker You can also use expressions in the same manner as for cursor dimensions See Label on page 258 271 User s Manual 272 Background Colour Select button Edit Colour to change background colour To change the default colour select command shell menu FilelOptions Col
85. in step 2 above 345 Simulator Reference Manual 346 If you find that this menu is not present then this means that the Verilog simulation facility is not available with your version of SIMetrix You will probably need to upgrade your license contact sales or support for assistance You should see an image of a symbol appear Place on schematic in the usual way Repeat step 3 for pulse_relay v Double click the pulse_relay device probably U2 You will see a dialog box showing a number of parameters We aren t going to change any settings this is just to point out this feature You should see two parameters at the bottom of the top section called divide_ratio and duty These are obtained from the Verilog file pulse_relay v Connect the rest of the circuit as shown in the diagram above S1 is a regular switch from menu Place Analog Functions Switch Make sure you don t forget the ground symbol Set up Simulation Set up a 200mS transient analysis in the usual way Select Gear integration using menu Simulator Choose Analysis then click on Advanced Options and select Gear Integration under the Integration Method group We do this to tidy up the response of the circuit this is by no means essential Run Simulation Run the simulation in the usual way It should take about 1 2 seconds maybe a little longer on an older machine 2 Chapter 13 Verilog HDL Simulation Plot the voltage on the relay c
86. in the Step Parameters section Number of steps has been set to 100 Start the analysis in the usual way It takes about 2 5 seconds with a 1 5G P4 The analysis will be repeated 10 times Now plot the output of the filter in the usual way Probe AC NoiseldB Voltage The result is the following 333 User s Manual dbV X1 inn dB Frequency Hertz As can be seen the specification is not met for some runs The SIMetrix Monte Carlo analysis implementation has many more features such as Random variation of device model parameters Support for matched devices Log file creation Seed selection to allow repeated runs with same randomly applied values Component Tolerance Specification 334 In this section we will only cover the simple case of how to specify tolerances on devices at the schematic level SIMetrix has much more comprehensive features for specifying tolerances aimed primarily at Integrated Circuit design For complete documentation on tolerance specification please refer to the Monte Carlo Analysis chapter of the Simulator Reference Manual Note that Monte Carlo analysis is not available with the SIMPLIS simulator Setting Device Tolerances To select individual device tolerances proceed as follows 1 Select component or components whose tolerances you wish to be the same You can individually select components by holding the control key down and left cli
87. in the following table See the Simulator Reference Manual for full details on these devices Device Description Arbitrary non linear source Analog non linear device Can express single or B device voltage or current in terms of any number of circuit voltages and currents including its own output S domain Transfer Function Linear block with single input and output each Block of which may be single ended or differential voltage or current Specified in terms of its S domain or Laplace transfer function Arbitrary Logic Block Digital device Implements any digital device combinational synchronous or asynchronous using a descriptive language Schematic support for functional blocks is provided by a number of devices under the menus PlacelAnalog Behavioural PlacelDigital Generic Devices currently provided are shown in the following table Device Description Non linear Transfer Function Based on the arbitrary non linear source This will create a schematic symbol with your specified inputs and outputs You enter the equation to relate them Laplace Transfer Function Based on the S domain transfer function block This will create a schematic symbol with specified input and output You enter an s domain transfer function Non linear Transfer Function Select menu PlacelAnalog BehaviourallNon linear Transfer Function This displays 146 Chapter 5 Components a Expression Use lox for input curre
88. inch Default False If true a message will be displayed in the command shell indicating the start and end of a simulation When set all commands are echoed to the command shell message window This is used primarily for script debugging Options dialog Default NOTEPAD EXE Default text editor Options dialog Default false If set stderr messages from the simulator will be displayed in the command shell window Some device models especially HiSim HV send messages to stderr Default false If set stdout messages from the simulator will be displayed in the command shell window Some device models especially HiSim HV send messages to stdout Chapter 14 Sundry Topics Name Type Description User interface support ExportRawFormat ForceGlobalHash GlobalCatalog unsupported GraphExtension GraphMainButtons GridPrintWidth Text Boolean Text Text Text Numeric Default SPICE3 No Possible values SPICE3 SPECTRE and OTHER Controls format of raw output See Exporting SPICES Raw Files on page 297 Default false In the simulator any node name found in a subcircuit that starts with a accesses a top level node of the same name but without the E g VCC in a subcircuit connects to VCC at the top level If this option is set the is not stripped so VCC ina subcircuit connects to VCC at the top level Default SHAREPATH
89. is a node so that it can correctly substitute the name when required REPEAT Start of compound keyword to create a general purpose repeating sequence SERIES Start of compound keyword to create a series combination PARALLEL Start of compound keyword to create a parallel combination STEP Used by series and parallel to return sequence number IF Conditional on the result of an expression IFD Conditional on whether a property is defined User s Manual 100 Keyword Description JOIN JOIN_PIN Returns information about a connected device Used JOIN NUM for current probes SEP Returns separator character Usually REF SPICE compatible component reference INODE Generates an internal node T Substitutes a property value treating it as a template VALUE Returns the resolved value PARAMSVALUE Returns passed parameters BUS Returns name of bus connected to the specified pin PROBE Similar to node but resolves mapped nodes in SIMPLIS mode FOREACHPIN Repeats for each pin NUMPINS Returns the number of pins on a symbol In the following descriptions the square bracket character is used to denote an optional item Square brackets in bold mean the literal square bracket symbol NODELIST NODELIST_H lt NODELIST map Inox gt lt NODELIST_H map Inox gt Replaced by the nodes connected to the device s pins NODELIST_H includes hidden global pins see Global Pins on page 76 used in hierarchi
90. is adjusted for best readability and does not necessarily scale exactly with the zoom magnification When the box is checked the font size follows the magnification in a linear fashion If selected the name of the property as well as its value will be displayed The value may contain expressions enclosed by and Y keywords enclosed by lt and gt and property names enclosed by These items will each be substituted with their resolved value to obtain the property text that is actually displayed 89 User s Manual Expressions may contain the usual arithmetic operators and may also use functions as defined in the Script Reference Manual Property names enclosed with are substituted with that property s value Keywords may be lt date gt lt time gt lt version gt lt if gt lt ifd gt and lt t gt lt date gt lt time gt resolve to date and time in local format and lt version gt resolves to an integer value which is incremented each time a schematic is saved The keywords lt if gt lt ifd gt and lt t gt behave in the same manner as the TEMPLATE property keywords of the same name See Template Property on page 96 for details Note that like template properties the resolution is performed in two passes with the property values being substituted first Adding Standard Properties Select menu Property PinlAdd Standard Properties This prompts you for values for the ref
91. is no need to change the other parameters AC Analysis Periodic Operating Point Trensient Sweep parameters a Start frequency 1k Decade Stop frequency 1Meg 3 Lingar Points per decade 2 To setup an AC analysis 1 Select AC sheet 2 Check the AC box under Select analysis 3 Enter parameters in Sweep Parameters section These have the same meaning as the equivalent SIMetrix analysis Manual Entry of Simulator Commands The analysis mode selected using SimulatorlChoose Analysis is stored in text form in the schematic s simulator command window also known as the F11 window If you wish it is possible to edit this directly Users familiar with the simulator s syntax may prefer this approach Note that the text entered in the simulator command window and the Choose Analysis dialog box settings remain synchronised so you can freely switch between the two methods To open the simulator command window select the schematic then press the F11 key It has a toggle action pressing it again will hide it If you have already selected an analysis mode using the Choose Analysis dialog box you will see the simulator controls already present The window has a popup menu selected with the right key The last item Edit file at cursor will open a text editor with the file name pointed to by the cursor or selected text item if there is one 57 User s Manual The simulator command window can be resized usi
92. is valid for the circuit being analysed Applying Snapshots to a Small Signal Analysis 1 Select menu SimulatorlChoose Analysis 2 Press Define Multi step Analysis for the required analysis mode 3 Select Snapshot mode The above procedure will result in the small signal analysis being repeated for each snapshot currently available Operating Point To specify a DC operating point analysis check DCOP Note that an operating point is performed automatically for all analysis modes and this is only useful if it is the only analysis specified Operating point analysis does not have any additional parameters so there is no tab sheet for it See Also OP in Simulator Reference Manual Viewing DC Operating Point Results on page 278 181 User s Manual Sweep Modes 182 Each of the analysis modes DC AC AC Noise and Transfer Function are swept That is they repeat a single analysis point while varying some circuit parameter There are 6 different sweep modes that can be applied to these analyses These modes are also used to define multi step analyses which are explained on page 200 The 6 modes are Device Temperature Parameter Model parameter Frequency not applicable to DC Monte Carlo As well as 6 different modes there are 3 different sweep methods Linear Decade List Dialog support for the List method is only available for the definition of Multi step analyses The simulator a
93. items then drag the items to the desired location You can rotate flip mirror the items see above while doing so To Move Items Disconnected Select items as described above then click the Detach toolbar button Move items to desired location then press left mouse key You can rotate flip mirror the items see above while doing so Chapter 4 Schematic Editor To Move Property Text Labels SIMetrix provides the ability to move property labels simply by dragging them with the mouse but this method is disabled by default To enable use menu File Options General then in Schematic sheet select Enable GUI property edits in the Property editing box Although this is of course a convenient method for moving property labels our recommendation is that this method is kept switched off Our philosophy is that it is better to move the symbol so that the label is clearly visible rather than move the label itself See Notes on Property Text Position on page 67 for a discussion You can also move a component s value by pressing control F7 and its reference using control F8 To move any other property select device then popup Properties Move To Duplicate Items Select items as described above then click the Duplicate toolbar button Move the items to your desired location then press left key to fix You can rotate flip mirror the items see above while doing so To Copy Across Schematics Select block you wish to copy Cho
94. lu W 0 5u AD 0 5u 0 5u Chapter 4 Schematic Editor The second pass would then be able to evaluate the expression and resolve lt nodelist gt see below The value of AD will be calculated according to whatever W is set to This is an alternative method of setting MOSFET area and perimeter values The method used with the standard symbols is different in order to remain compatible with earlier versions Note that if the property value contains any of the special characters lt gt these will be treated literally So if for example a property value was tailres no attempt would be made to evaluate tailres in the second pass Keyword Summary The keywords available are summarised in the following table and explained in detail below Keyword Description NODELIST Substituted with full list of nodes for device NODELIST_H PINLIST Substituted with full list of pin names for symbol NODE n Substituted for individual node MAPPEDNODE n As node but order defined by mapping property if present PINNAMES Equivalent to pinnames lt pinlist gt except that no substitution takes place if the nopinnames switch is specified for the Netlist command MAPPEDPINNAMES As pinnames but order is altered according to mapping property if present NODENAME This is not replaced by any text but signifies that the item following is a node name The netlist generator must be able to identify any text that
95. mm See also GridPrintWidth CurveWeight Numeric Default 1 Options Sets the line width in pixels dialog of graph curves Note that although widths greater than 1 are clearer they normally take considerably longer to draw This does however depend on the type of adapter card and display driver you are using DataExtension Text Default sxdat dat Options Default file extension for dialog data files DataGroupDelete Text Default OnStart Options Determines when dialog temporary simulation data is deleted Possible values Never OnStart OnClose and OnDelete See Graph Probe Data Analysis on page 359 for details DefaultLib Text Default SHAREPATH SymbolLibs default sxslb Name and location of default symbol library DefaultPersistence Default 0 Options Sets the number of curves dialog that are kept for graph fixed probes 0 means that all curves are kept 1 means that only 1 is kept at a time 367 User s Manual 368 Name DevConfigFile DigAxisHeight DisplaySimProgressMessage EchoOn Editor EnableSimStderr EnableSimStdout Type Text Numeric Boolean Boolean Text Boolean Boolean User interface support Description Default SHAREPATH DeviceConfig cfg Name and location of device configuration file See Simulator Reference Manual for details Default 8 0mm Options Height of digital axis in mm dialog Screens are typically 75pixels
96. most circuits obey them anyway and they do not impose serious limitations on the capability of the simulator There must always be at least one ground symbol on every circuit Every node on the circuit must have a dc path to ground For example two capacitors in series form a node which does not have DC path to ground If you do have a floating node you can provide a DC path to ground by connecting a high value resistor e g 1G between it and ground Capacitors without initial conditions do not have have a DC path But if you set an initial condition on a capacitor a DC path is formed and this method is an alternative to using a resistor to provide a DC path Also note that inductors with an initial condition do not have a DC path This is because they are treated as a constant current during the calculation of the DC bias point If using a high value resistor to make a DC path we recommend that you also place a low value capacitor in parallel with it This is not always necessary but can help avoid problems with transient analysis convergence It is best to choose a realistic value that would represent what the capacitance would really be in the real world circuit There must not be any zero resistance loops constructed from voltage sources inductors without intial conditions or capacitors with initial conditions If you do have such loops you can insert a low value resistor You should choose a value that represents what the resis
97. of TEMPPATH Directory where temporary simulation data files are placed Only functional for Linux systems Defines how a terminal session may be started for the Shell script function See details for the Shell function in the Script Reference Manual File extension used for text files See the Simulator Reference Manual for a full explanation Chapter 14 Sundry Topics Name Type Description User interface support TranscriptErrors Boolean Default false If true incorrectly typed commands will be entered in the history box The drop down list in the command line that shows previously entered commands UndoBufferSize Numeric Default 10 Options Number of levels of dialog schematic undo See Creating a Schematic on page 42 UpdateClosedSchematics Boolean Allows SIMetrix to write to closed schematic if required See Closed Schematics on page 243 UpdateCurvesNoDeleteOld Boolean Default false Plot If true old curves are not Update deleted when using the Curve Update Curves feature Settings UpdateCurvesNoFixSelected Boolean Default false Plot If true update includes Update selected curves when Curve using the Update Curves Settings feature UseAltGraphPrintStyles Boolean Determines method of Options differentiating curves on dialog monochrome hardcopies See Graph Printing on page 358 UseGreekMu Boolean Default false No If true the u used to denote 10e 6 will be display
98. of schematic components If auto repeat is enabled a new symbol to be placed is automatically displayed after each placement This speeds the placement of many instances of the same device Enable smart wiring enable the smart wiring algorithm See Wiring on page 67 for details about smart wiring Allow route through connected is an option for the smart wiring algorithm that allows it select routes that pass through existing wires that are already connected to the source or target destinations Option to hide the schematic s grid This is only relevant for SIMetrix SIMPLIS products Sets the initial simulation mode when opening a new schematic If most or all of your work is with SIMPLIS check SIMPLIS This will save time switching to SIMPLIS mode for all new schematics Width in mm of printed axis Width in mm of printed grid lines Width in mm of printed minor grid lines Width in mm of printed curves When printing on monochrome printers or if Use markers for colour is selected curves are differentiated using different line Chapter 14 Sundry Topics styles solid dashed etc and marker shapes circles squares etc For a large number of curves both methods are used but for just a few you can use this option to state your preference Prefer line styles printed curves will first be differentiated using line styles Prefer curve markers Printed curves will first be differentiated using curve markers Use markers for co
99. of the simulation This will help with locating an initial operating point 124 Chapter 5 Components Device Parameters MOSFETs Zener Diodes IDmax This should be set to the peak operating current expected during circuit operation The parameter extraction process will work out a suitable value which is often satisfactory VDmax This should be set to the expected maximum steady operating voltage during circuit operation This is not the breakdown voltage of the transistor but the voltage that is used to characterise the behaviour in the off state Temperature This parameter will set the simulation temperature used when extracting the SIMPLIS model It will only be meaningful if the temperature is properly supported in the SPICE model Model level Values are 0001 0011 1032 0001 is the simplest and fastest while 1032 provides the greatest detail but is the slowest Maximum Power Set this to the maximum rated power for the device The conversion process needed to create the SIMPLIS model is often able to look up this value in a database If not you will be prompted to enter a suitable value Initial condition 0 Illegal and don t use 1 At Zener Voltage 2 Voltage between Vz and Fwd Biased 3 Forward Biased Set this according to how you expect the Zener to be biassed at the start of the simulation Set to 0 if you are unsure 125 User s Manual
100. or use the right click menu Copy Symbol Enter a new user name for the symbol It isn t usually necessary to change the internal name To copy symbols to a new library use the same drag and drop procedure as for moving but hold the control key down while doing so You can do this for a single symbol or for an entire category Note that when copying to a new library the symbol retains its user name and internal name There will therefore be duplicates installed unless they are renamed Deleting Symbols To delete a symbol select it then press Delete or the right click popup menu of the same name You can also delete an entire category in the same way Renaming Symbols Select a symbol then press F2 or the right click popup menu Rename You can also rename a category in the same way 109 User s Manual Note that this only renames the user name of the symbol There is no method of changing the internal name other than making a copy with a new name then deleting the original Creating a New Category To create a new category select the parent category where you wish it to be placed then click Create or the popup menu of the same name In the dialog that opens select the Category button and enter the new name Creating a New Symbol Select the category where you wish the symbol to be placed then click Create or the popup menu of the same name Enter the desired user name An internal name will be automatically entere
101. protected Value subcircuit_name Name used to reference subcircuit definition Can be changed by user after placing on schematic Ref component_reference E g U Automatically allocated when placing symbol on schematic Most symbols possess these properties anyway the important fact is that the model property must be set to X When defining a symbol from scratch these properties can be defined in one go in the graphical symbol editor with Property PinlAdd Standard Properties To use the sub circuit definition SIMetrix must be able to find it There are various places where it can be put and means of telling SIMetrix of the location These are the choices a Place the definition directly in the simulator command or F11 window see Manual Entry of Simulator Commands on page 57 If placed at that location it will be read in unconditionally and SIMetrix will not need to search for it XN Put in a separate file and pull in to the schematic with INC control see Simulator Reference Manual placed in simulator command F11 window As 1 this will be read in unconditionally p Put in a library file and reference in schematic with LIB control see Simulator Reference Manual placed in simulator command F11 window Similar to 2 but more efficient if library has many models not used in the schematic Only the devices required will be read in gt Put in a library file and install it using the procedure des
102. proximity effect Ideal Transformers Ideal transformers may be used in both SIMetrix and SIMPLIS modes Note that SIMPLIS operation is more efficient if the coupling factors are set to unity To define an ideal transformer select the menu PlacelPassives Ideal Transformer This will open the following dialog box J Define Ideal Transformer Ex Configuration Define windings Primaries S Select winding Sec 1 1 Secondaries 1 S Ratiotoprimay1 1 2 Inductance and coupling Primary 1 10u Inter secondary 1 inductance coupling Inter primary Primary secondary 1 coupling coupling cee E Configuration Specify the number of primaries and secondaries You can specify up to ten of each Define turns ratio Select Winding Lists all windings except primary 1 Ratio to Primary 1 Enter the turns ratio with respect ratio primary 1 Inductance and coupling Primary 1 Inductance Self explanatory Inter primary coupling Coupling factor between primaries Inter secondary coupling Coupling factor between secondaries Primary secondary coupling Coupling factor from each primary to each Chapter 5 Components secondary This method of implementing an ideal transformer is not totally general purpose as you cannot arbitrarily define inter winding coupling factors If you need a configuration not supported by the above method you can define any ideal transformer using ideal inductors and the Mutua
103. real real Interpolates argument to 324 specified number of evenly spaced points IsComplex any Returns TRUE if argument is 324 complex length any Returns number of elements in 324 vector In real complex Natural logarithm 324 log log10 real complex Base 10 logarithm 325 mag magnitude real complex Magnitude same as abs 326 maxidx real complex Returns index of vector where 326 largest value is held Maxima real real string Returns locations of maxima of 326 specified vector mean real complex Returns statistical mean of all 326 values in vector Mean1 real real real Returns mean of data in given 327 range minidx real complex Returns index of vector where 327 smallest value is held Minima real real string Returns locations of minima of 327 specified vector norm real complex Returns argument scaled so that 327 its largest value is unity ph phase real complex Returns phase of argument 328 phase_rad real complex As ph but result always in 328 radians Range real complex real real Returns range of vector 328 re real real complex Return real part of argument 328 Ref real complex Returns reference of argument 328 Rms real Returns accumulative RMS value 328 of argument 318 Chapter 11 Command and Function Reference Function name Description Page no RMS1 real real real Returns RMS of argument over 328 specified range rnd real Returns random number 329 RootSu
104. referred to as EXAMPLES Simulation for the Novice When measuring a real circuit you would probably connect up a power source bench power supply perhaps maybe also some signal source then switch it on and take measurements using probably an oscilloscope You can also make adjustments to the circuit and see the effects straight away For simulation you have a choice of analysis modes and not all of them have an exact real life equivalent The analysis mode that most closely resembles the method of bench testing a circuit described above is transient analysis This performs an analysis over a specified by you time period and saves all the results i e all the voltages and currents in the circuit to your hard disk The difference between real life testing and simulation is that the simulation is not running all the time If you want to see the effects of changing a component value you have to change it then re run the simulation But note there is a potentiometer device that automates this procedure see Potentiometer on page 136 21 User s Manual In order to solve the circuit the simulator has to calculate the voltage at every node at every time point Disk space is cheap and plentiful so SIMetrix saves all these values as well as the device currents Not all simulators do this some require you to state in advance what you want saved After the run is complete you can then randomly probe the circuit to loo
105. required to create plots will start being output at this time Start plotting data under Plot data output has a similar function but is subtly different See below for details This is the time at which the process of creating plot data is started This is similar to Analysis parameters gt Start saving data but subtly different The process of generating plot data in SIMPLIS is a two stage operation When the simulation is running it saves internal state data known as switching instance data The switching instance data then has to be transformed to actual plot data This latter process is known as Post Simulation Processing or PSP Analysis parameters gt Start saving data specifies the start time for switching instance data while Start plotting data specifies when PSP begins It is perfectly valid to set Analysis parameters gt Start saving data to zero so that all switching instance data is saved but to set Start plotting data to some later time Here is an example to illustrate why you might want to do this Suppose you are simulating a large circuit to 100mS but you are only interested in the last 20mS i e 80mS to 100mS You could set Start saving data to 80mS to reduce the amount of data generated and also to speed up the run However after the run is complete you look at the data and realise that you need to see what is happening from the start of the run As no data at all was output from the start the only thing to d
106. resolution printing 2 Scalable Vector Graphics svg This is a relatively new format and is not supported by many applications However it is the only scalable format available in Linux 3 Bitmap default image size png jpg bmp These are available on all platforms are widely supported by graphics applications but these are not scalable formats and so do not offer good quality when printed using high resolution printers PNG is the default format if you do not choose a file extension and generally this format works well for schematics and graphs To choose JPG JPEG format or BMP windows bitmap format you must explicitly enter jpg or bmp file extensions respectively With this option the image size will match the image size currently displayed on screen If you wish to specify a different image size use next option 4 Bitmap specify image size png jpg bmp As 3 above but you must explicitly define the image resolution in pixels You will be prompted for this when you close the file selection dialog box Saving Graphs You can save a graph complete with all its curves cursor settings and annotations to a binary file for later retrieval Note that all the graph data is stored not just that needed 277 User s Manual for the current view If a long run was needed to create the graph the file could be quite large Saving Select command shell menu FilelGraphlSave As or graph menu FilelSave As to save
107. resuming the simulation To do this 1 Pause simulation 2 Place a probe on the circuit in the normal way 3 Resume simulation Changing Update Period and Start Delay The update period of all fixed probes can be changed from the Options dialog box Select command shell menu FilelOptionsIGeneral and click on the Graph Probe Data analysis tab In the Probe update times seconds box there are two values that can be edited Period is the update period and Start is the delay after the simulation begins before the curves are first created Random Probes 228 General Behaviour A wide range of functions are available from the schematic Probe and Probe AC Noise menus With a few exceptions detailed below all random probe functions have the following behaviour If there are no graph windows open one will be created If a graph window is open and the currently displayed sheet has a compatible x axis to what you are probing the new curve will be added to that sheet E g if the currently displayed graph is from a transient analysis and has an x axis of Time and you are also probing the results of a transient analysis then the new curve will be added to the displayed graph If however the displayed curve was from an AC analysis its x axis would be frequency which is incompatible In this case a new graph sheet will be created for the new curve If you want to force a new graph sheet to be created press F10 This will create
108. saved as 7 MODELLIB OnSemi mod Path option variables StartupDir ScriptDir BiScriptDir TempDataDir PSpiceIniPath DefaultLib SymbolsDir Automatic path matching is invoked whenever these values are set or modified 353 User s Manual Symbol file locations Schematic symbol file paths may be stored using symbolic constants Automatic path matching is invoked whenever a library is installed Notes for Windows The automatic path matching system will correctly match a drive based path e g h projects proj1 with its mapped UNC path e g server1 c projects proj1 provided the drive based path points to a network share and not a local drive For example if the project fie contains the entry Project serverl c projects projl and server1 c is mapped to the H drive then the file H Projects proj1 cell23 sxcmp will be stored as Project cell23 sxcmp However if you are actually running SIMetrix from the machine server and server1 c is the share name for the local C drive then C Projects proj1 cell23 sxcmp will not be recognised as equivalent to Project cell23 sxcmp This limitation is due to security restrictions in Windows NT 2000 XP SiMetrix Command Line Parameters A number of command line parameters may be supplied to the SIMetrix binary SIMetrix exe on Windows SIMetrix on Linux when starting the program The full syntax is as follows SIMetrix exe schematic_file s startup_script i n
109. schematics see Schematic hierarchical HighlightIncrement option variable 370 HistoCurveStyle options variable 370 Histogram function 322 Histograms 283 HPBW function 291 I if template property keyword 104 ifd template property keyword 105 Iff function 322 IR function 323 im function 324 Impedance probing 230 Importing data 297 incscript property 96 393 User s Manual Inductor editing values 134 initial condition 135 mutual 133 non linear 130 151 sweeping 183 InhibitAutoCD option variable 370 Initial condition capacitor 135 force resistance 199 inductor 135 integ function 324 Integration method 178 Interp function 324 InvertCursors option variable 371 IsComplex function 324 J join template property keyword 105 join_num template property keyword 105 join_pin template property keyword 106 K Keyboard 304 L Laplace expression 150 length function 324 LibraryDiagnostics option variable 371 List file 278 In function 324 log function 325 log10 function 325 LogicDefExtension option variable 382 lot property 96 LPBW function 292 M mag function 326 mappednode template property keyword 99 mapping property 96 match property 96 maxidx function 326 Maxima function 326 MaxVectorBufferSize option variable 371 MC_ABSOLUTE_RECT option variable 336 394 Index MC_MATCH_RECT option variable 336 Mean function 326 Mean function 327 Menu reference 304 Message window 303 MinG
110. so that it acquires the new PARAMS property you have just added to the symbol definition To do this proceed as follows 1 2 Select the instance of the symbol in the schematic editor Select right click menu Update Properties Accept the default action this will add any properties missing from the existing instance but present in the symbol definition Editing Parameters To edit parameters after they have been added proceed as follows 1 Select hierarchical instance Chapter 4 Schematic Editor 2 Select right click menu Edit Add Properties 3 Double click the item with name PARAMS 4 Enter new values as required in the Value box Accessing Parameters in the Child Schematic You can use any parameter defined on the symbol in an expression to define a component value or model value You should enclose the expression with curly braces and F Missing Hierarchical Blocks When a hierarchical schematic is opened SIMetrix needs to locate the component files that contain the symbols used for each hierarchical block If however the file for a particular component is missing or is in the wrong location then SIMetrix will not be able to display that component s symbol Unlike library symbols component symbols are not stored locally in the schematic file In order to make it possible to resolve the problem SIMetrix instead puts a place holder symbol in place of the missing symbol The place holder s
111. source To enter one of these select the Text tab and enter the appropriate syntax for the source Please refer to Voltage source in the Simulator Reference Manual for more information on these sources The AC sheet is for AC analysis only Chapter 3 Getting Started With the universal source you can specify transient AC and DC specifications simultaneously This is not possible with any of the other sources Other Sources Sine Tone Burst Generates a sequence of sinusoidal bursts with a user defined number of cycles per burst burst frequency and tone frequency Use menu Place Voltage Sources Sine Tone Burst then place device in the usual way Editing the device will bring up a dialog with 6 parameters Parameter Description Burst Freq Burst frequency Tone Freq Frequency of the sinusoidal tone Num Tone Cycles Number of sinusoidal cycles in each burst Peak Peak voltage Offset Offset voltage Points Per Cycle Minimum number of time steps in each sinusoidal cycle Increasing this number will improve the accuracy of the simulation at the expense of simulation speed Swept Sinusoid Generate a sinusoidal signal with linearly increasing frequency Use menu Place Voltage Sources Swept Sine then place in the usual manner Editing the device will bring up a dialog with 6 parameters Parameter Description Start Frequency Starting frequency End Frequency Frequency at the end of the ramp 49 User s Manu
112. support Verilog designs SIMetrix has a new device called VSXA A VSXA device is defined by a MODEL statement and this in turn specifies a Verilog design file The Verilog file is expected to contain a top level module definition and this module defines the external connections to the analog system via Verilog ports 341 Simulator Reference Manual Any number of Verilog devices i e VSXA instances can be placed in a SIMetrix netlist schematic The actual design presented to the Verilog simulator will be a single Verilog definition but SIMetrix handles the task of creating this from the user s individual Verilog design files and schematic netlist interconnection of VSXA instances See Verilog HDL Interface VSXA in Chapter 4 of the Simulator Reference Manual for more details about the VSXA device Using Verilog HDL in SiMetrix Schematics 342 Creating Schematic Symbols The SIMetrix schematic editor provides a feature that will create and place a schematic symbol from a Verilog file This feature reads the Verilog file and determines the inputs and outputs along with the names of the ports It also reads any parameters defined From this information it creates a symbol with inputs on the left and outputs on the right It also creates an edit facility to edit any parameters defined in the Verilog module To create a schematic symbol from a Verilog design proceed as follows 1 In the schematic editor select menu Help C
113. the subject of several volumes In principle an almost unlimited range of IIR filtering operations may be performed using this function Any text on Digital Signal Processing will provide further details Users should note that using this function applied to raw transient analysis data will not produce meaningful results as the values are unevenly spaced If you apply this function to simulation data you must either specify that the simulator outputs at fixed intervals select the Output at interval option in the Choose Analysis dialog box or you must interpolate the results using the Interp function see page 324 Example The following graph shows the result of applying a simple first order IIR filter to a step The coefficients used give a time constant of 10 the sample interval In the above the sample interval was 1Sec so giving a 10uSec time constant As can be seen a first order IIR filter has exactly the same response as an single pole RC network A general first order function is Yn Xn Co Yn C1 where Cy 1 exp T t and c exp T t and t time constant and T sample interval The above example is simple but it is possible to construct much more complex filters using this function While it is also possible to place analog representations on the circuit being simulated use of the IIR function permits viewing of filtered waveforms after a simulation run has completed This is especially useful if the run took a long
114. think you may wish to restart the transient run after it has completed and you wish the noise generators to continue to be enabled after the restart then you must specify this time beyond the initial stop time before starting the analysis You should avoid however using inappropriately large values for this stop time as this may noticeably slow the simulation and in extreme cases could cause an out of memory condition RTN Mode This affects how the noise sources are handled between noise steps The choice is between Mode 0 and Mode 1 Mode 0 is nearly always the best mode but this can underestimate the noise is some cases The difference between these modes is explained as follows Real time noise introduces current sources across all noisy junctions The magnitude of these sources is determined at each noise step according to the operating point of the device and a randomly generated value whose magnitude is determined from the noise equations The RTN mode affects how this current source is set between noise steps This is not a problem if the operating point of the device is unchanged the source simply ramps linearly to the next noise step The problem occurs when the operating point changes especially if it changes profoundly as would be the case if a transistor switches rapidly from an on state to an off state In this scenario the magnitude of the noise current would be high in the on state but fall away to near zero in the off state
115. to identify the type of device The SIMetrix netlist generator prefixes the model property 115 User s Manual and a symbol to the component reference to comply with this This makes it possible to use any component reference on the schematic Device Model Pin no Pin Pin function property names XSPICE device A Arbitrary Sources B 1 p 2 n Bipolar junction transistors Q 1 c Collector 2 b Base 3 e Emitter 4 s Substrate Capacitor C 1 p 2 n Current Controlled Current F 1 p Source 2 terminal 2 n Current Controlled Current F 1 p output Source 4 terminal 2 n output 3 any control 4 any control Current Controlled Voltage H 1 p Source 2 terminal 2 n Current Controlled Voltage H 1 p output Source 4 terminal 2 n output 3 any control 4 any control Current Source l 1 p 2 n Diode D 1 p Anode 2 n Cathode GaAs FETs Z 1 d Drain 2 g Gate 3 s Source Inductor L 1 p 2 n Junction FET J 1 d Drain 2 g Gate 3 s Source MOSFET M 1 d Drain 2 g Gate 3 s Source 4 b Bulk Resistors R 1 p 116 Chapter 4 Schematic Editor Device Model Pin no Pin Pin function property names Transmission Line T 1 p1 Port 1 Term 1 lossless 2 ni Port 1 Term 2 O lossy 3 p2 Port 2 Term 1 4 n2 Port 2 Term 2 Voltage Controlled Current G 1 p output Source 2 n output 3 cp contol 4 cn control Voltage Controlled Switch S 1 p Switch term 1 2 n Switch term 2 3 cp control 4 cn control Voltage Controlle
116. to create graphs of your circuit s signals were explained in Getting Started on page 42 This chapter provides a full reference on all aspects of probing and creating graphs Elements of the Graph Window Main Window Curve Legend J PSU Waveforms Selected File Edit Cursors Annotate Curves Axes View Measure Plot IARAA S AMENE EBRIETA 1P Y1 Handle Use to undock NL3 P Y2 panel It can be positioned Ti m J on another edge or float free Legend panel Selected Y axis is black Unselected Y axis is __ grey Y2 KL3 P A S1 P V 1 94 1 96 1 98 2 202204206208 21 212 Time kSecs 20Secs div x 2 05226kSecs y 3 43892A Windows and Tabbed Sheets Normally new graphs are created within the same window as a tabbed sheet A row of tabs will appear at the top of the graph window allowing you select which graph you wish to view You can also create a new graph window using the menu ProbelNew Graph Window This will create an empty window to which you may add new graphs 221 User s Manual Graph Toolbar Measure 3dB high pass Measure 3dB low pass Move curve to selected axis erid Measure average cycle Measure RMS cycle Name curve Measure fall time Hide selected curves Moasure tise tim Show selected QQQq s tH hy EEIE Undo graph mg Create new grid Fit height Create new axis F
117. to determine how many devices are connected T lt T prop_name gt Does the same as prop_name except that the properties value is evaluated as if it were a template itself With prop_name the literal value of the property is always used Note that recursive properties will simply be substituted with nothing E g lt T TEMPLATE gt will return empty if used in a template property called TEMPLATE VALUE lt VALUE gt Returns the VALUE property value unless the instance is a hierarchical block in which case it returns the name of the referenced subcircuit definition PARAMSVALUE lt PARAMSVALUE gt Returns the instance s parameters This is defined by the PARAMS property and will be prefixed with the parameter separator for subcircuit devices This is params for SIMetrix mode and vars for SIMPLIS mode This keyword will also include tolerance parameters defined by the properties LOT TOL and MATCH if present BUS lt BUS n gt Returns the name of the bus connected to th n th pin Chapter 4 Schematic Editor PROBE lt PROBE n gt In SIMetrix mode behaves identically to NODE In SIMPLIS mode will return the mapped node name if relevant This will happen if the node has a name defined by a terminal symbol Instead of the assigned node number this keyword will return the node name prefixed by a As the name imlies this is intended for use with probe symbols FOREACHPIN lt FOREACHPIN var lt body
118. to the stop time The minimum time step for example You should avoid therefore entering inappropriate values for stop time Data Output Options Sometimes it is desirable to restrict the amount of data being generated by the simulator which in some situations can be very large You can specify that data output does not begin until after some specified time and you can also specify a time interval for the data Output all data Output at PRINT step The simulator generates data at a variable time step according to circuit activity If Output all data is checked all this data is output If Output at PRINT step is checked the data is output at a fixed time step regardless of the activity in the circuit The actual interval is set by the PRINT step This is explained below If the Output at PRINT step option is checked the simulator is forced to perform an additional step at the required interval for the data output The fixed time step interval data is not generated by interpolation as is the case with generic SPICE and other products derived from it Start data output No simulation data will be output until this time is reached PRINT step PRINT is a simulator command that can be specified in the netlist to enable the output of tabulated data in the list file See Simulator Reference Manual for details of PRINT The value specified here controls the interval used for the tabulated output provided by PRINT but the same valu
119. top level or root Descending into a Block 1 Select the block then either press Control E or select HierarchylDescend Into 2 If schematic attached to the block is already open it will be brought into view If it isn t it will be opened Note that the schematic will now be associated with the block that you entered This is important if you have more than one block attached to the same schematic and you intend to plot curves from it after a simulation This is explained more fully in the section on simulating hierarchical designs Ascending to Parent Schematic 1 Select HierarchylAscend 2 If schematic is open it will be brought into view if it isn t it will be opened Placing Full vs Relative Path Components can be placed using their full path or a relative path When placed with a full path the component file is referenced using its full file system path name e g C Projects Proj123 amplifier sxcmp This allows the schematic file that uses the component to be freely moved as long as the component file stays in the same place However if the component file is moved the schematic will no longer be able to locate it 74 Chapter 4 Schematic Editor When placed with a relative path the component file is referenced with a file system path name relative to the schematic that uses it Most likely the component file will be in the same directory or folder as the schematic and will therefore be referenced by its file name
120. using script commands You can also define your own toolbars and buttons Full details may be found in the Script Reference Manual Component Placement Options You can specify whether or not you prefer multiple or single placement of components By default placement of components from the schematic tool bar is repetitive while placement of components from the menus is done one at a time This can be changed Select the command shell menu FilelOptions General In the schematic sheet the options available are presented in the Placement box Adding and Removing Worksheets A number of standard sizes of worksheet are included See menu PlacelWorksheets The worksheet menus automatically protect the worksheet after it has been placed This prevents it from being selected To delete a worksheet use the PlacelWorksheetIDelete Worksheet menu You should avoid placing a worksheet from the PlacelFrom Symbol Library menu as it will not be protected if you do this Finding and Specifying Net Names When a simulation is run a netlist of the schematic is created and this is delivered to the simulator The netlist generator automatically assigns names to every net or node of the circuit There are some situations where you need to find the name of a net For example in noise analysis see page 189 you must specify an output node In these situations you can either find the name of the net that the netlist generator assigned or alternatively you can
121. voltage Probe voltage between two Menu Probe Place Fixed points Diff Voltage Probe dB Probes db value of signal Menu Probe AC voltage Only useful in AC Noise Fixed dB Probe analysis 223 User s Manual Probe Type Description To Place Phase Probes phase of signal Menu Probe AC voltage Only useful in AC Noise Fixed phase Probe analysis Bode plot Plots db and phase of vout Menu Probe AC vin Connect to the input and Noise Bode Plot Probe output of a circuit to plot its gain and phase Bus plot Plots bus signal in logic Menu Probe Place Fixed analyser style Bus Probe Power plot Plots the power in a device Menu Probe Place Fixed The power probe must be Power Probe attached to a single pin of the device It doesn t matter which pin the power plotted in the instantaneous power in the whole device These probes are simply schematic symbols with special properties When you place a fixed probe on the schematic the probed value at the point where you place the probe will be plotted each time you run the simulation Current probes and power probes must be placed directly over a component pin They will have no function if they are not and a warning message will be displayed Fixed Probe Options All probe types have a large number of options allowing you to customise how you want the graph plotted For many applications the default settings are satisfactory In this section the ful
122. where output is written This command is intended as an aid to DC operating point convergence Sometimes the dc operating point solution is known from a previous run but took a long time to calculate By applying the known solution voltages as nodesets prior to the operating point solution the new DC bias point will be found much more rapidly The method is tolerant of minor changes to the circuit The old solution may not be exact but if it is close this may be sufficient for the new solution to be found quickly If SaveRhs is executed after an AC analysis the values output will be the real part only Set Set temp option_spec option_spec Defines an option temp If specified the option setting will be temporary and will be restored to its original value when control returns to the command line i e when all scripts have completed option_spec Can be one of two forms Form1 option_name Form2 option_name option_value option_name can be any of the names listed in Options on page 357 For options of type Boolean use form1 For others use form 2 See Also Options on page 357 Unset on page 316 Show Show file filename append filename noindex noHeader plain force clipboard names names width width expression expression Displays the value of an expression This command can be used to export data from the simulator in ASCII form See Data Import and Export
123. you want X Axis to be linear or logarithmic If Auto is selected the axis X or Y will be set to log if the x values are logarithmically spaced For the Y axis it is also necessary that the curve values are positive for a log axis to be selected No Change Keep axis scales how they are Only relevant if adding to an existing graph Defined Set axis to scales defined in Min and Max boxes Axis Labels Sheet This sheet has four edit boxes allowing you to specify x and y axis labels as well as their units If any box is left blank a default value will be used or will remain unchanged if the axis already has a defined label Fixed Bus Probe Options Select device and press F7 in the usual manner A dialog box will show similar to that shown in Bus Probe Options on page 237 But you will notice an additional tabbed sheet titled Probe Options This allows you to select an axis type and graph in a similar manner to that described above for fixed voltage and current probes 227 User s Manual Using Fixed Probes in Hierarchical Designs Fixed probes may successfully be used in hierarchical designs If placed in a child schematic a plot will be produced for all instances of that child and the labels for each curve will be prefixed with the child reference Adding Fixed Probes After a Run has Started When you add a fixed single ended voltage or current probe after a run has started the graph of the probed point opens soon after
124. 0 im 10m taili Real Time Noise This is an extension of transient analysis rather than a separate analysis mode When activated real time noise sources are added to all noisy devices with a magnitude and frequency distribution calculated using the same equations used for AC noise analysis This allows noise analysis to be performed on sampled data systems and oscillators for which AC noise analysis is not appropriate Real time noise is not available with all versions of the product Contact sales for details Setting Up a Real Time Noise Analysis 1 Select menu SimulatorlChoose Analysis 2 Select Transient check box on the right 3 Select Transient tab at the top Enter parameters as described in the following sections 4 Setup transient analysis parameters as detailed on page 176 5 Check Enable real time noise Select Define to set up real time noise parameters Enter values as explained below 193 User s Manual 194 Interval This specifies the sampling interval of the noise generators You should set this to a maximum of about 1 3 of the highest noise frequency of interest Note that the interval also forces a maximum time step so short intervals can result in long simulation times Start time The time at which the noise generators are switched on Defaults to 0 Stop time The time at which the noise generators are switched off This defaults to the stop time of the transient run If you
125. 0mV The basic requirement of the design is that the pulse shape should be preserved DC precision is important but is not critical The above is our first attempt at a design but has not yet been optimised This example circuit has been setup to be ready to run 2 To start the simulation select from the schematic window SimulatorlRun or press F9 The simulation will not take long on a modern machine less than half a second You will see a graph of the output voltage appear 60 50 40 30 Amplifier Output mV 201 0 2 4 6 8 10 Time pSecs 2uSecs div As can be seen our amplifier doesn t work all that well There are two problems 1 There is substantial ringing on the rising edge probably caused by the capacitative load 2 The falling edge is somewhat sluggish The sluggish falling edge is caused by the absence of any standing current in the output emitter follower Q3 To rectify this we will place a resistor from the emitter to the 5V rail The resulting schematic is shown below 23 User s Manual 24 To make this modification proceed as follows 1 3 Press the Resistor button in the component toolbar Alternatively select the menu PlacelPassiveslResistor Box shape or if you prefer PlacelPassives lResistor Z shape A resistor symbol will appear Place this in the location shown in the diagram above Click the left mouse button to fix it to the schematic You may no
126. 10 _ vour C1 10 m C5 62p This circuit can be found in EXAMPLES MonteCarlo cheb sxsch The circuit is a 5th order low pass 7kHz Chebyshev filter with a 1dB passband ripple specification Its nominal response is Chapter 12 Monte Carlo Analysis X1 out V 1k 2k 4k 10k 20k 40k 100k Frequency Hertz This circuit is to be used in an application that requires the gain of the amplifier to remain within 2dB of the dc value from 0 to 6kHz A 1dB ripple specification therefore seems a reasonable choice Clearly though the tolerance of the capacitors and resistors may upset this To investigate a Monte Carlo analysis is required The standard component tolerances are 10 for capacitors and 1 for resistors With the example circuit the tolerances are already applied but the procedure for doing this is as follows 1 Select menu item Monte CarlolSet All Resistor Tolerances 2 Enter 1 The is recognised 3 Select menu item Monte CarlolSet All Capacitor Tolerances 4 Enter 10 The example circuit has already been set up to run 100 steps of Monte Carlo To view the settings 1 Select menu SimulatorlChoose Analysis 2 Note in the section Monte Carlo and Multi step Analysis the Enable multi step box is checked 3 Press the Define button 4 Note that in the Sweep Mode section Monte Carlo is selected and
127. 35 User s Manual 136 The infinite capacitor is a built in primitive component and is actually implemented by the voltage source device The infinite inductor is a subcircuit using an infinite capacitor and some controlled sources Potentiometer The potentiometer may be used in both SIMetrix and SIMPLIS modes To place select the menu PlacelPassives Potentiometer This device can be edited in the usual manner with F7 Edit Part popup This will display Se J Edit Potentiometer l Parameters Resistance 10k a Wiper Position 0 5 a Note You can also use shift UP and shift DOWN to adjust the wiper position Increment decrement 50m i step size E Run simulation after position change Enter Resistance and Wiper position as required Check Run simulation after position change if you wish a new simulation to be run immediately after the wiper position changes The potentiometer s wiper position may also be altered using the shift up and shift down keys while the device is selected Edit Inc dec step size to alter the step size used for this feature Lossless Transmission Line Select from menu PlacelPassiveslTrans Line Lossless or press hot key T Editing in the usual way will display Chapter 5 Components Characteristic Impedance Si a Delay 50n a Relative Tolerance 1 S Absolute Tolerance 1 8 Enter the Characteristic Impedance Z0 and Delay as indicated Lossy Tra
128. 5 1 064e 07 4 6483 4 5821 If the above was read in as a text file using OpenGroup text a new group called Chapter 9 Graphs Probes and Data Analysis textn where n is a number would be generated The group would contain three vectors called time Voltage and Voltage2 The vectors Voltage and Voltage2 would have a reference of Time Time itself would not have a reference To read in complex values enclose the real and imaginary parts in parentheses and separate with a comma E g Frequency 000 004 009 013 018 023 028 032 037 042 047 61579 252886 911386 591388 292992 016298 761406 528416 317429 128548 VOUT a 45 5 5 CS 5 5 3 3 5 5 94 94 94 94 94 94 94 94 94 94 94 260997 0 002837811 260997 0 00285091 260996 0 002864069 260995 0 002877289 260994 0 00289057 260993 0002903912 260992 0 002917316 260991 0 002930782 26099 0 00294431 260989 0 0029579 260988 0 002971553 299 User s Manual Chapter 10 The Command Shell la J SIMetrix SIMPLIS Command Shell kedai File Simulator SIMPLIS Graphs and Data Help ntb welcome to SIMetrix SIMPLIS Micron VX version 6 20 Beta4 x64 Execute command Drop down list for command history Command line essage window Command Line 300 The command line is at the top of the command shell See diagram above The vast majo
129. 75 User s Manual Running Analyses in Asynchronous Mode In asynchronous mode the simulation runs in the background and you are free to carry on using the SIMetrix environment for entering schematics or viewing results from previous analyses Because the simulation is running in the background it is necessary for the simulation process to be detached from the front end environment and for this reason it is not possible to use GRAPH or fixed probes to plot simulation results during the course of the run Also you must manually load the simulation data when the run is complete Starting an Asynchronous Run 1 Select menu Simulator Run Asynchronous Note a simulation status box appears similar to the box used for synchronous runs but with an additional Activity box at the bottom Any messages generated by the simulator will be displayed here 2 When the simulation is complete you must load the data manually The name of the file to load will be displayed in the command shell when the simulation starts Select menu FillDatalLoad Temporary Data to load data file You will be able to cross probe the schematic used to run the analysis in the normal manner once this file is loaded Pausing and Aborting Asynchronous Runs To pause press the Pause button Note that you can load the data generated so far after pausing the run as described above To abort a run press the Close button Running an Analysis on a Netlist You can ru
130. 77 StartupDir option variable 353 StartUpFile option variable 377 StatusUpdatePeriod option variable 377 step template property keyword 104 Stimulus 46 Subcircuits 153 calling from a schematic 155 creating from schematic 154 expanding 199 passing parameters 157 SumNoise function 329 Sweep modes 182 186 Switch voltage controlled 138 with hysteresis 138 Switches command line 301 Symbol editor 83 SymbolExtension option variable 382 Symbolic path names 351 Symbols see Schematic symbols SymbolsDir option variable 353 378 System requirements 19 T tan function 329 TempDataDir option variable 353 378 Temperature setting 199 sweeping 183 with multi step analysis 202 template property 96 97 TEMPPATH 352 TextExtension option variable 382 Timestep too small error 178 tol property 96 Tolerance current 199 relative 198 voltage 199 Toolbar graph 222 403 User s Manual schematic 62 configure 71 TotalVectorBufferSize option variable 378 TranscriptErrors option variable 379 Transfer function analysis 195 plotting results 231 Transformer ideal 132 non linear 130 Transient analysis 176 181 SIMPLIS 207 Transient snapshots 179 Transmission line lossy 137 Truncate function 329 Tutorial 21 U UIC 135 Undo Graph Zoom 268 UndoBufferSize option variable 379 unitvec function 330 Unselecting schematic items 65 Unset command 316 UpdateClosedSchematics option variable 244 379 UpdateCurvesNoDeleteOld optio
131. A graph of the current at that point will be created A new graph sheet will be created for it unconditionally Probing dB and Phase for AC Analysis In AC analysis you will probably want to plot signals in dB and you may also want to plot the phase of a signal 1 Select the schematic menu item Probe AC Noiseldb Voltage for dB or Probe AC NoiselPhase Voltage 2 Using the mouse place the cursor over the point on the circuit you wish to plot 3 Press the left mouse button The new curve will be added to any existing graph if the X axis has the same units Otherwise a new graph sheet will be created Probing dB and Phase for AC Analysis On New Graph Sheet 1 Create an empty graph sheet by pressing F10 or selecting menu ProbelNew Graph Sheet 2 Proceed as in above section Differential Voltage Probing The schematic menu ProbelVoltage Differential allows you to plot the voltage difference between two points When you select this menu click on the schematic twice The first is the signal node and the second the reference node Advanced Probing The menu ProbelMore Probe Functions provides many more probing functions selectable from a tree structured list More advanced plotting can be achieved with the menu ProbelAdd Curve This opens a dialog box allowing you to enter any expression and which also provides a range of options on how you wish the graph to be plotted 61 User s Manual Chapter 4 Schematic
132. Analysis You can pause the simulation by selecting the Pause button on the simulator status dialog box To restart select the Resume button the Pause button changes name when simulation pauses or the SimulatorlResume menu item When a simulation is paused you can carry on using the program as if the simulation had completed This includes plotting results of the simulation completed so far If you decide you do not wish to continue the run there is no need to explicitly abort it You can just start a new run in the normal way If you do this you will be asked if you would like to resume the pending run If you answer No the pending run will be automatically aborted and the new run started Aborting an Analysis There is actually never a need to explicitly abort an analysis If you decide you do not wish to continue a run just pause it as described above Pause is the same as abort except that you have the option to change your mind and restart Nevertheless there is an abort facility Simply select the SimulatorlAbort menu When you abort a run you will not be able to restart it There is just one benefit of aborting a run instead of pausing it When an analysis is aborted the simulator frees up the memory it needed for the run Note that this does not happen after a run completes normally If you need to free up simulator memory after a normal run completes type Reset at the command line Not available with SIMetrix Intro 1
133. At the same time the switch moves from a strongly conducting state to a non conducting state In Mode 1 the source ramps linearly between noise steps and the operating point of the device is not considered until a new noise step is reached This method can in some cases grossly over estimate the noise In Mode 0 the noise source is recalculated at each time step and adjusted according to the operating point of the device This method tends to underestimate the noise but not by the same excessive amount that Mode 1 overestimates In general we can t think of a good reason to use Mode except as a confidence check Both methods should give similar results if the noise step is small enough so a useful check is to run a circuit for a small time using each mode but with a very small noise step The results for each should be similar Chapter 7 Analysis Modes See Also Real Time Noise analysis in the Simulator Reference Manual This includes the results of some comparisons between AC noise and real time noise Transfer Function Transfer function analysis is similar to AC analysis in that it performs a swept small signal analysis However whereas AC analysis calculates the response to all circuit nodes from a usually single input source transfer function analysis calculates the individual responses from each source in the circuit to a single specified output node This allows for example the series mode gain common mode gain and power s
134. D see Install CD on page 16 and may also be downloaded from our web site Notation 308 Symbols Used Square brackets These signify a command line parameter or switch which is optional Pipe symbol This signifies either or Ellipsis This signifies 1 or more optional multiple entries Fonts Anything that would be typed in is displayed ina fixed width font Command line parameters are in italics Case Although upper and lower cases are used for the command names they are NOT in fact case sensitive Examples OpenGroup text filename Both text a switch and filename a parameter are optional in the above example So the following are all legitimate OpenGroup OpenGroup text OpenGroup run23 sxdat OpenGroup text output txt DelCrv curve_number One or more curve_number parameters may be given So the following are all legitimate DelCrv 1 2 3 DelCrv 1 Command Summary Chapter 11 Command and Function Reference Only a few of the approximately 240 available commands are detailed in this chapter and a list is given in the table below Documentation for the remainder is provided in the Script Reference Manual This is available as a PDF file on the install CD see Install CD on page 16 and can also be downloaded from our web site Command name Description DefKey DefMenu DelMenu ListStdKeys OpenGroup ReadLogicCompatibility Reset SaveRhs Set Show UnSet
135. DGE sxsch 203 User s Manual This was setup to perform a multi step analysis with the parameter duty stepped from 0 1 to 0 9 This is the result duty 0 9 uty 0 7 duty 0 5 Currentin L1 A duty 0 3 1 0 0 2 0 4 0 6 0 8 1 2 1 4 1 6 1 8 2 Time mSecs 200uSecs div Safe Operating Area Testing 204 Overview Safe Operating Area SOA is not a separate analysis mode but a feature that can be enabled with DC or Transient analyses With SOA testing you can set maximum and minimun limits for any simulation quantity and the simulator will display when those limits are violated To use SOA testing you must do two things 1 Define the SOA limits for the models or devices you are using 2 Enable and configure SOA testing Item 1 above is covered in detail in the Simulator Reference Manual see section titled SETSOA and also the LIMIT parameter described in the section titled MODEL Setting up simple limit tests using some simple schematic symbols is described below Defining Simple Limit Tests Schematic Symbols Three schematic symbols are provided that allow the definition of simple limit tests that report the following Chapter 7 Analysis Modes 1 Over and under voltage on a single node 2 Over and under current on a single device pin 3 Over and under differential voltage on a node pair Use the following menus to place these devices
136. Define output using S vanable Frequency scale factor 1 a Device Type Inout Outout B iraneter tinction Single ended voltage Single ended voltage Single ended current Single ended current Impedance V I Differential voltage Differential voltage Sees a S Differential curent Differential curent a aalo The operation of the various controls is described below Definition Enter an expression using the S variable to define the frequency domain transfer function The above shows the example of a second order response See Laplace Expression below for details of the expression syntax Frequency scale factor Multiplier for frequency Device type Transfer function Expression defines output input Impedance V I Two terminal device expression defines voltage current Admittance I V Two terminal device expression defines current voltage Input Input configuration for transfer function Output Output configuration for transfer function 149 User s Manual 150 Laplace Expression When you close the box a symbol will be created according to the selections you make for device type input and output As seen in the above examples the transfer function of the device is defined by the model parameter LAPLACE This is a text string and must be enclosed in double quotation marks This may be any arithmetic expression containing the following elements Operators means rais
137. Editor 42 Creating a Schematic The schematic editor has been designed to be intuitive to use and you may not need to read too much about it Here we describe the less obvious procedures If you have SIMetrix SIMPLIS make sure you are in the correct mode before entering a schematic See above section Chapter 3 Getting Started IE TONG PIKORRA ARIE h t Cut Wiring tool Detach Zoom in Duplicate Zoom out Undo Zoom box Save schematic Flip Close schematic Mirror Open schematic Rotate In the following notes references are made to the schematic tool bar The diagram above shows the standard toolbar and the function of each button To Place a Component If it is a simple device which only needs a value such as a resistor or capacitor select the appropriate symbol from the tool bar or Place menu For other devices that require a part number it is easiest to use the parts browser Select menu PlacelFrom Model Library and select your desired device To Change Value or Device Type for a Component First select it then double click or select schematic popup Edit Part or press F7 A dialog box appropriate for the type of component will be displayed For devices requiring a model name a list of available types will appear To Rotate Mirror or Flip a Component Use the Rotate toolbar button see diagram above or key F5 to rotate a component This operation can be performed while a component is being placed or while a block
138. Enter an appropriate selection under Save Options Its usually best to select All This will instruct SIMPLIS to save all data for subsequent plotting In most cases the above is all you need to do For information on the remaining transient analysis settings see Transient Analysis on page 176 Periodic Operating Point Analysis POP To setup a POP analysis 1 Select Periodic Operating Point sheet AC Transient Periodic Operating Point Triggering F Use POP Trigger schematic device See menu Place gt Analog Functions gt POP Trigger Trigger gate Trigger conditions Oto 1 1tod Conditions Max period lu a Cycles before 5 launching POP Chapter 3 Getting Started 2 Check the POP box under Select analysis 3 Check the Use POP Trigger Schematic Device box You will need to place a POP trigger device on your schematic See below 4 TIn the Max period box enter a value that is larger than the largest possible value of your circuits switching period You must place on your schematic a POP trigger device Select menu PlacelAnalog Functions POP Trigger After placing the device connect its input to a switching frequency signal You do not need to connect the output of this device Select the trigger device then press F7 Enter suitable values for Ref Voltage and Hysteresis so that it will always reliably trigger on the switching waveform If you don t use the output there
139. High Switch switches on when control voltage rises above this threshold 139 User s Manual 140 Parameter Description On Delay Delay between high threshold being reached and switch starting to switch on Off Delay Delay between low threshold being reached and switch starting to switch off Switching Time Total time switch takes to switch on On Switching Time Total time switch takes to switch off Off Older versions of this model did not include the switching time parameters If you wish to update a delayed switch already placed on a schematic to include this parameter use the Edit Add Properties menu to change the PARAM_MODEL_NAME property to delayed_switch_V3 Parameterised Opamp Implements an operational amplifier and is available from menu This is available from menu PlacelAnalog Functions Parameterised Opamp It is defined by the parameters listed below Parameter Description Offset Voltage Fixed input offset voltage Bias Current Average of input currents Offset Current Difference between input currents Open loop gain Open loop gain Simple ratio not dB Gain bandwidth Gain bandwidth product Pos Slew Rate Slew rate in V sec despite name this is the slew rate in both positive and negative directions Neg Slew Rate This is included for compatibility with the SIMPLIS model but is currently not implemented in the SIMetrix model CMRR Common mode rejection ratio Simple ratio not dB PSRR
140. IMPLIS mode will not be the same as in SIMetrix mode However SIMetrix is able to convert some SPICE models for use with SIMPLIS This conversion operation is performed behind the scenes and you don t necessarily need to know what is happening However it is very useful to understand the process that is being performed in order to understand the devices behaviour under SIMPLIS This conversion process is described in the next section SPICE to SIMPLIS Conversion SIMetrix is able to convert the following SPICE models types to SIMPLIS models Type Supported SPICE Conversion Method Implementation Diode Primitive model or Simulated parameter extraction subcircuit Zener Diode Primitive model or Simulated parameter extraction subcircuit BJT Primitive model Parameter translation MOSFET Primitive model or Simulated parameter extraction subcircuit Supported SPICE Implementation refers to the way the SPICE model must be implemented for the conversion operation to be supported SPICE models can be either primitive models using the MODEL statement or can be sub circuits using SUBCKT ENDS Conversion Method describes the method used to perform the conversion Parameter translation is a simple process whereby the MODEL parameters are read from the model and used to compile a SIMPLIS model using a knowledge of the SPICE device equations Simulated parameter extraction is a more sophisticated and general purpose method that can be applie
141. LIS_DATA folder The deck file is an ASCII file that list the components in the design with their connections and values Its format is similat to a SPICE netlist The picture below illustrates the process of matching a component in the schematic to an entry in the deck file 217 User s Manual TL431 U2 TERIA A 100n gauss 0 05 IC 1 7 T 1 c6 4 75k 7 i 33k Re Locate deck file in SIMPLIS DATA by 1 I E directory c5 C5_val gauss 0 05 IC 1 7 e V iew in text editor a Find component value a i sinplc_meloa loa H SelOscillatingConverter_POP_AC_Tran_2 deck Error Amp 1 rage o A a 11 3 27 2 2n C4 13 17 0 01u CS 37 39 2 27927033192142e 008 IC 1 7 a 14 C6 35 39 9 64269647128782e 008 IC 1 7 X C7 16 0 ELEC CAP_L13 3 1 C8 34 0 10n aanu 1 X D1 0 27 ZENER_DIODE 4 X D2 14 15 DIODE_SPICESS ven a 20 NTOANR QDOTORCA In the above diagram note the line for C5 shows a value of 2 2797033192142e 008 in the deck file Performance Analysis and Histograms Once a SIMPLIS multi step or Monte Carlo analysis is complete the data can be analysed in exactly the same way as for SIMetrix multi step analyses This includes the performance analysis and histogram features For more information see Performance Analysis and Histograms on page 280 Initial Condition Back annotation 218 Overview On each run SIMPLIS generates a file called the init
142. Leave blank le a to use default Measures RMS Restore Factory Definition Full description n siginifies new line Create new measurement Displayed below list box Optional Name ey Requires cursors to be switchedon F The Measurement Definitions Manager allows you to edit both built in and custom measurement definitions Select measurement Select measurement you wish to edit from this list Restore Factory Definition This button will be enabled for any built in definition that has been edited in some way Press it to restore the definition to its original For custom definitions this button s label changes to Delete Press it to delete the definition It is not possible to delete built in definitions Create new measurement You can create a completely new empty measurement or you can copy an existing one to edit Enter a name then press Create to create a new empty definition To copy an exsiting definition select the definition under Select measurement then press Copy selected Measurement definition Define measurement There are five entries Label as displayed on graph See similar for Define Measurement GUI page 262 Expression See similar for Define Measurement GUI page 262 263 User s Manual 264 Format template See similar for Define Measurement GUI page 262 Full description See similar for Define Measurement GUI page 262 Requires cursors to be switched on If checked the measurement w
143. N 0 4 715E6 5E6 SEG 11 17 282 RE amp Select Local Global Use global library model Use local model The top half of the above box shows the definition of the model in the library The bottom half shows an editable local copy of the model To begin with this will be exactly the same as the library model shown in the top half But you may edit this as desired but note you should not edit the top line starting subckt or bottom line ends This model will then be used instead of the global library model if you select the check box at the bottom Use local model You may subsequently swap between the global and local models at any time The local model is stored in the schematic instance as a property and will continue to be 121 User s Manual available even if you select the global model at some time This allows you to freely swap between the library model and your own modified version Note that only models defined in the global library may be viewed and edited in this way Models defined locally in the F11 window or models defined using lib or inc may not currently be viewed or edited Numbered Components in SIMPLIS 122 This section applies only to the SIMetrix SIMPLIS product SIMPLIS works in a quite different way to SIMetrix SPICE and as a result its models for semiconductor devices are completely different For that reason the selection of devices available from PlacelFrom Model Library when in S
144. NoStopOnError Boolean If disabled scripts and Options multi command lines i e dialog several commands on the same line separated by are aborted if any individual command reports an error NoStopOnUnknownParam Text Specifies action to be taken Options in the event of an unknown dialog parameter being encountered in a MODEL statement Choices are TRUE No action taken simulation continues normally FALSE An error will be raised and the simulation will abort WARN A warning will be displayed but the simulation will continue This will be overridden by a OPTIONS setting of the same name Refer to Simulator Reference Manual for details 373 User s Manual Name Type Description User interface support OldUserCatalog unsupported OmitAsciiRevision unsupported PassUnres Template unsupported Precision PrintOptions PrintWireWidth 374 Text Boolean Boolean Numeric Text Numeric Default sxappdatapath user Location and base name without extension of user catalog file used by versions 5 2 and earlier This file is used to populate the current user catalog file Default false If true the revision value is not written to ASCII schematic files For backward compatibility Default false If true unresolved template values in netlists will be passed literally Default behaviour is no output Default 10 Precision of numeric values displayed
145. PSpice Schematics program Schematics is the original MicroSim schematic editor but is no longer supported Current PSpice releases use Orcad Capture for schematic entry SIMetrix is not able to read Orcad Capture schematics Chapter 4 Schematic Editor Configuring the Translator Before using this facility it must be configured This is simply a matter of specifying the location of the PSPICE INI file which PSpice uses to store symbol library locations Proceed as follows 1 Select menu FilelOptions General 2 Select File Locations tab 3 Double click the item PSpice inifile 4 Locate the file PSPICE INI This is usually at the root folder for PSpice e g C Program Files Orcad PSpice PSPICE INI Press Open when you have found the file The above assumes you are using version 9 of PSpice Earlier versions stored their settings in a similar manner but the file name was different and in a different location For example MSIM INI located in the windows directory Note we have only tested version 9 2 and the evaluation version 8 0 Some earlier versions used different inifile section names and in these cases the file will need to be manually edited For more information see the on line help topic Schematic Editor gt gt PSpice Schematics Translation If you don t have PSpice If you do not have PSpice on your system then you will need to create a PSPICE INI file that contains the location of the PSpice symbol librarie
146. Peak To Peak Rise Time 10 90 manual Rise Time 10 90 auto Rise Time custom auto Fall Time 10 90 manual Fall Time 10 90 auto Fall Time custom auto Duty cycle Overshoot relative Le eae a a Measures mean value In the right hand pane labelled Choose Measurement select Mean In the Pre process group select Cursor span Click Ok to close the dialog box 34 Chapter 2 Quick Start You should see a value of about 2 8W displayed This is somewhat more than the 517mW average but is still well within the safe operating area of the device However as we noted earlier the inductor is ideal and does not saturate Lets have a look at the inductor current 1 Select schematic menu ProbelCurrent in Device Pin New Graph Sheet 2 Left click on the left pin of the inductor L1 This is what you will see L1 P A 0 0 2 0 4 0 6 0 8 1 Time mSecs 200ySecs div This shows that the operating current is less than 1 5A but peaks at over 6A In practice you would want to use an inductor with a maximum current of around 2A in this application an inductor with a 6A rating would not be cost effective We will now replace the ideal component with something closer to a real inductor 1 Delete L1 2 Select schematic menu PlacelMagnetics Saturable Transformer Inductor A dialog box will be displayed See picture below Select 0 secondaries then enter 34 in the turns edit
147. Place Probe Watch Voltage Place Probe Watch Current Place Probe Watch Differential Voltage Each of these symbols can be edited in the usual way Each has three parameters that specify 1 The minimum limit Use a large negative number e g 1e100 if you don t wish to specify a minimum limit 2 The maximum limit Use a large positive number e g 1e100 if you don t wish to specify a maximum limit 3 A label The default value is 7REF that will resolve to the device s component reference You can enter any literal value instead Setting Up SOA Testing 1 Select menu Simulator Choose Analysis 2 Select the SOA tab 3 Under SOA mode choose either Summary output or Full output In summary output mode only the first violation for each SOA device will be reported In full output mode all violations are reported 4 In Results to choose where you would like the results reported Note that writing results to the message window is a time consuming operation and you avoid selecting this option if you are expecting a large number of violations Running Simulation Run the simulation in the normal way If there are any violations the results will be reported in the location or locations specified in the Results to section Advanced SOA Limit Testing The simulator control SETSOA allows much more sophisticated definitions for SOA limits In particular you can define limits for all devices belonging to a s
148. Property Format 98 Template Scripts eececcceeeeesesseeeeeeeseeteeeeseeteaee Symbol Library Manager Operations ies ece crite a se a Editing System Symbol Libraries eee 110 PSpice Schematics Translation ccccseeeeseeeeeeees 110 Configuring the Translator eccecceeseeeeeeeeteees 111 If you don t have PSPice ecceseeseeeeeeeeeteeeeeeees 111 Reading PSpice Schematics ccesceeeeeeeee 111 Installing PSpice Libraries for Use with SlMetrix 111 What the Translator will dO eeeseeeeseeeeneeeeeees 111 LAMITATIONS kaai eaa aaa ae Ea aE an EAREN aces 112 Using Schematic Editor for CMOS IC Design 112 MOSFET Symbols 0 e ceecceeseeeeeeeeseeeeeeeeeeetseeees 112 Automatic Area and Perimeter Calculation 114 Editing the MOS Symbls cecceeceeeeeeeeeeeeeees 114 Further Information cccessccseeeeeeseeeeseeeeeeeneeesseees 115 How Symbols are Stored eccesesseeeeeeeeeeeeeeeeees 115 Summary of Simulator Devices 0 0 eee 115 Chapter 5 Components Numbered Components c ccecceeseeeeeeeeeeeeeeeeeeeeeeeeeas 118 Selecting a Model by Specification c 008 120 Viewing and Editing Models eeeeeeseeeeeeees 121 User s Manual Numbered Components in SIMPLIS ecceeeeeee 122 SPICE to SIMPLIS Conversion cceceeeeeees 122 Generic COMPONENTS ce eeeceeeeeeeeeeeeeteeeeeteeteeeeeeeeea
149. REF R1 VALUE 1k and MODEL R and the device is connected to external nodes R1_P and R1_N this is the end result R1 1 R1_P 1 1k R1 2 1 2 1k R1 3 2 3 1k 103 User s Manual 104 R1 4 3 4 1k R1 5 4 R1_N 1k If the num element is empty e g in above example if SERIES property were empty or missing then no output will be made at all The example above can be used for any two terminal component There must however be a SERIES property present on the symbol PARALLEL lt PARALLEL num lt line gt gt Creates a parallel combination of the device described in line For example lt parallel parallel lt lt ref gt lt nodelist gt VALUE gt gt creates a parallel combination of components The number in parallel is determined by the property PARALLEL Note that the REF keyword returns the component reference appropriately modified by the MODEL property and appended with the sequence number If PARALLEL 5 REF R1 VALUE 1k MODEL R and the device is connected to external nodes R1_P and R1_N this is the end result R1 1 R1_P R1_N 1k R1 2 R1_P R1_N 1k R1 3 R1_P RIN 1k R1 4 R1_P R1_N 1k R1 5 R1_P RIN 1k If the num element is empty e g in above example if PARALLEL property were empty or missing then no output will be made at all The example above can be used for any two terminal component There must however be a PARALLEL property present on the symbol STEP lt STEP gt Used with SERIES and PARALLEL keywords
150. ROW Incompatible inputs cannot be connected Out out resolution table A table with the number of rows and columns equal to the number of logic families listed in the header Both column and rows represent outputs The table defines how outputs from different families are treated when they are connected The entry may be one of four values Row take precedence Column takes precedence Doesn t matter Currently identical to ROW Incompatible outputs cannot be connected Reset Reset Frees memory associated with most recent simulation run It is not normally necessary to use this command unless available memory is low and is needed for plotting graphs or other applications Note that Reset does not delete the data generated by a simulation only the internal data structures set up to perform a run These are automatically deleted at the beginning of a new run SaveRhs SaveRhs nodeset filename Creates a file containing every node voltage inductor current and voltage source current calculated at the most recent analysis point The values generated can be read back in as nodesets to initialise the dc operating point solution Chapter 11 Command and Function Reference nodeset If specified the values are output in the form of a nodeset command which can be read back in directly Only node voltages are output if this switch is specified Otherwise currents in voltage sources and inductors are also output filename File
151. S and 750uS then the function would create them by interpolation Note that the function will not extrapolate points before the start or after the end of the input vector unitvec real Returns a vector consisting of all 1 s Argument specifies length of vector vector real Returns a vector with length specified by the argument The value in each element of the vector equals its index XFromY real real real real Input vector Y value Interpolation order 1 or 2 Direction of slope 0 any 1 ve 1 ve Returns an array of values specifying the horizontal location s where the specified vector argument 1 crosses the given y value argument 2 in the direction specified by argument 4 If the vector never crosses the given value an empty result is returned The sampled input vector is interpolated to produce the final result Interpolation order is specified by argument 3 XY real real Returns a vector with y values of argument land x values of argument 2 This function provides a means of creating X Y plots using the GRAPH control See the Command Reference chapter of the Simulator Reference Manual for details YFromX real real real Input vector Y value Interpolation order Returns an array of values usually a single value specifying the vertical value of the specified vector argument 1 at the given x value argument 2 If the given x value is Chapter 11 Command and Function Re
152. SIMETRIX SPICE AND MIXED MODE SIMULATION USER S MANUAL Trademarks PSpice is a trademark of Cadence Design Systems Inc Hspice is a trademark of Synopsis Inc Contact SIMetrix Technologies Ltd 78 Chapel Street Thatcham RG18 4QN United Kingdom Tel 44 1635 866395 Fax 44 1635 868322 Email info simetrix co uk Internet _http www simetrix co uk TECHNOLOGIES I SiMetri x Copyright SIMetrix Technologies Ltd 1992 2012 SIMetrix User s Manual 6 March 2012 Table of Contents Table of Contents Chapter 1 Introduction Installation and LICENSING eee eeeseeeeeeeeeneeeeeneeeeeaes 16 Install GDievis s oe chs apa danclessescthasdeiek cauctsasaeschavionss 16 What Is Simetrixe c aenean data twine 16 Whatis SIMPLIS aaa aaa ra aee dati eeeei dene 17 Why Simulate desaise piane nan aaea 18 System Requirements ccccceeeeeeeeeceeeeeeeeeeeeeeeeeeeseeeees 19 Operating System eeeeeeeeeeeeeeeeeeeneeeeeeeeenernen eenen 19 Hardware sois atn e EEN 19 Recommended System ecceeceeeceeeeretseeeeeeeneees 20 About the 64 bit Version esseere 20 Chapter 2 Quick Start Examples and Tutorials Where are They 21 Simulation for the NOVICE ceccseeseeseeeeneeeeetees 21 Tutorial 1 A Simple Ready to Run Circuit 22 Tutorial 2 A Simple SMPS Circuit c ceeeeeeees 30 Tutorial 3 Installing Third Party Models eee 37 Chapter3 Getting
153. Started Simulation Modes SIMetrix or SIMPLIS e 42 Using the Schematic Editor ceeceeeeeeseeeeeeeeeeeneeenees 42 Creating a Schematic 00 eeeeceeeeeeeeeeeeeeteeeeeeeeneetees 42 Gircuit RUES ima eee ae eee 45 GCirCuit StIMULUS aininn nede ducing i cdieedhs cunesotedeesels 46 Waveform Generator ccccccccccccccceeeeceseseesesessseserees 46 PWL SOUICE wo cccccccccccccceeeeeeceseeseseessesesssseeeenenseeeuess 47 Power Supply Fixed Current Source ccecee 47 AG SOUPCE EATE thes te es Meee eee 47 Universal SOUrCE ccccccccccccceceeeeeseesssssseeeeeeeeeeenees 48 Other SOUICES ccccccseceeeeeeeeeeeeeceeeeeeeeseseeseseessnenees 49 Analysis ModaSenin 50 OQVGIVICW 2s Ak chee ens eee ee 50 Using the Choose Analysis Dialog eeeee 50 Setting Up a SIMPLIS Simulation ceee 55 Manual Entry of Simulator Commands 006 57 Running the Simulator eceseceeeeeeeeeeeeeeeeeeeeeneeeeeeeeaees 58 SIMEHrix 00 0 ccccccceeeeeessssseceeeeeeeeeceeeeeseeeseesseseeesesnenanes 58 User s Manual SIMPLES A Bee teat a th bc ns Leet he ps bh Fees 58 Plotting Simulation ReSUuIts eeeeeeeseeseeeeteeeeeeeenees 58 OVEIVICW ccccceeecescssssscceeeeeeeeeeceeeeeeesecsesesseesseesstas 58 Fixed Probes siria a a wens detente 59 Random Probes ccccccccececceesssseseceeeeeeeeeeaneeseneens 60 Chapter 4 Schematic Editor Schematic Windows and Sh
154. SumOfSquares real real real Start x value Default start of vector End x value Default end of vector Similar to RMS1 function but returns the root of the sum without performing an average sign real Returns if argument is greater than 0 otherwise returns 0 sin real complex Return sine of argument in radians Use sin_deg if the argument is in degrees sqrt real complex Returns the square root of the argument If the argument is real and negative an error will result If however the argument is complex a complex result will be returned SumNoise real real real Identical to RootSumOfSquares function See page 329 tan real complex Return tan of argument in radians Use tan_deg if the argument is in degrees Truncate real real real Data Start x Value End x value Returns a portion of the input vector with defined start and end points Interpolation will be used to create the first and last points of the result if the start and end values do not coincide with actual points in the input vector Arguments 2 and 3 define the beginning and end of the vector 329 User s Manual 330 Example Suppose we have a vector called VOUT which was the result of a simulation running from 0 to 1mS We want to perform some analysis on a portion of it from 250uS to 750uS The following call to Truncate would do this Truncate VOUT 250u 750u If VOUT did not actually have points at 250u
155. Symbol ex Define Symbol Save to User Name Library file intemal Name npon Component file Category Semiconductors BJTs Current schematic file All references to symbol automatically updated F C Program Files S Metrix620 support Symbol Libs semiconductors sxslb ae eS Define Symbol User Name Enter the name as you wish it to be displayed in the dialog box opened with the schematic menu PartslAll Symbols Define Symbol Internal Name For a new symbol an internal name will automatically be entered when you type the User Name In most cases you can leave it at that However the internal name must be unique across the whole model library so there may be situations where you will need to change it If you are unsure whether the name used is unique prefix it with something that is very unlikely to be used anywhere such as your initials The resulting name does not need to be meaningful to anyone else it is an identifying code not a descriptive name Define Symbol Category Enter a category to determine how the symbol will be listed in the dialog box opened with the schematic menu PlacelFrom Symbol Library Sub categories are separated using a semi colon Note that you can easily move symbols to different categories Chapter 4 Schematic Editor using the symbol library manager So if you are unsure at this stage what category to use you can place it in a temporary category and move it later
156. TAPATH Path of the SIMetrix application data directory See Application Data Directory on page 355 for details SHAREPATH Path of the root support directory used for various support files used by SIMetrix such as model and symbol libraries User constants must be defined in the configuration file See Configuration Settings on page 355 for more information User constants are defined in the Locations section of the file Currently these must be added by hand using a text editor The format used is as follows Locations symbol_definitions Where symbol_definitions is any number lines of the form symbolname symbolvalue symbolvalue may be any sequence of characters that are valid for a system path name and may contain spaces There is no need to enclose it in quotation marks even if the value contains spaces Nested definitions to any level are permitted That is symbolvalue may also itself use other symbolic constants Recursive definitions won t raise an error but will not be meaningful UNC paths e g server c project may be used for symbolvalue Comments may be added to the project file prefixed with a semi colon Chapter 14 Sundry Topics Configuration File Example The following shows examples of symbolic path name definitions in the configuration file Lines such as these may be placed anywhere in the file but we recommend that they are placed at the end Project file Locations Project c Projects pro
157. Without you having to tell it SIMetrix already knew that the SKN1001 is an NPN transistor This is because it is a primitive device defined using a MODEL control Such devices are built in to the simulator and SIMetrix can determine the part type simply by reading the MODEL control in TUTORIAL3 MOD This is not the case with the other device in the model library This is an opamp and is defined as a subcircuit This is a module made up of other components in this case BJTs diodes resistors and current sources SIMetrix can t tell what type of device this is It knows that it has five terminals and it knows where the electrical model is located in the file system but it doesn t know what schematic symbol to use for this model SIMetrix will ask you for this information when you try and place it Follow this procedure 38 Chapter 2 Quick Start 1 Repeat the steps 1 5 above but instead select the SXOA1000 device instead of the SXN1000 Notice that when you select the device in the right hand side you see the message SIMetrix does not know what symbol to use for this model Press Place to resolve 2 After pressing the Place button you should see the following box STEP 1 Select a suitable category for this pat __ Cneose Category for SXOA1000 F you cant find one press New Category Unassigned and enter a new category of your choice STEP 2 Select a suitable symbol for this part Define Symbol for SXOA1000 Sele
158. a default choice of CVER or Icarus With Linux only CVER is available with a standard setup but Icarus may also be added reasonably easily if you have this installed on your system Note that the Verilog simulator is also used to enumerate the ports and parameters of a Verilog module separately from the main simulation This task is always performed by GPL Cver regardless of the simulator setting Timing Resolution Verilog simulations use 64bit integer values throughout and this includes time To convert to real time the value of each time tick needs to be defined This is the timing resolution defined here The default value is 1fs and there is no benefit in changing this unless the simulation 264 runs for longer than x lfs This is approximately 18000 seconds Note that the timescale setting used to define the values of delays etc within each module is not affected by this setting 343 Simulator Reference Manual Open Console for Verilog Process If you set this check box a console window Windows terminal window Linux will open for the run and any messages generated by the Verilog simulation will be displayed in that window Tutorial To demonstrate the basic features of Verilog simulation we will work through the trivial example shown below IDEAL D1 clock pulse_relay U2 This circuit pulses a relay for 10mS every 100mS driven by a 100kHz clock The relay coil is mod
159. able to handle these multiple instances it needs to be presented with a top level module that defines the interconnections between them This top level module is generated automatically by SIMetrix on each simulation run and is called by default vsx_root v Chapter 14 Sundry Topics Chapter 14 Sundry Topics Saving and Restoring Sessions Overview You can save the current session for later restoration This is useful in the situation where you are in the middle of editing schematics or studying simulation results but you need to interrupt this work maybe at the end of a working day While in some situations you might simply be able to leave your computer switched on and logged in or maybe use a Hibernate mode these methods are not always practical or indeed reliable The SIMetrix save session feature will save the current state of all open schematics all open graphs and any simulation data so that it can be restored at a later time Saving a Session Select menu File Save Session Restoring a Session You can only restore a session if all graphs and schematics are closed and there is no current simulation data loaded This is the normal state when SIMetrix has just been started If you wish to restore a session when SIMetrix has been in use since first starting you can either shut down and restart or close all windows and graphs then select menu Graphs and Data Delete Data Group press Select All then Ok To re
160. about its DC operating point Like DC AC Noise and Transfer Function analyses AC analysis is a swept mode and can operate in any of the 6 modes documented in Sweep Modes on page 182 With some of these modes e g sweeping a resistor value it will be necessary for the DC operating point to be recalculated at each point while with others such as frequency sweep it is only necessary to calculate it at the start of the run For AC analysis to be meaningful at there must be at least one voltage or current source on the circuit with an AC specification To find out how to set one up see AC Source on page 47 Setting up an AC sweep 1 Select menu SimulatorlChoose Analysis 2 Select AC check box on the right 3 Select AC tab at the top Enter parameters as described in the following sections Sweep Parameters Start value Stop value Defines sweep range stop and start values Points per decade Number of points Defines sweep range The number of points of the sweep is defined per decade for a decade sweep For a linear sweep you must enter the total number of points Define Sets up desired sweep mode See Setting up a Swept Analysis on page 185 Monte Carlo and Multi step Analysis See page 200 Data output Check the Save all currents check box to enable the output of all current data including semiconductor devices If this box is not checked the current into devices such as transistors and diodes wil
161. act Two Curves Plot Multiply Two Curves Select one of the above menus and follow instructions given 2 Using the Add Curve dialog box With this method select menu Probe Add Curve then enter an expression as desired To access an existing curve s data simply click on the curve For more information see Plotting an Arbitrary Expression on page 238 AC Analyis Notes on Curve Arithmetic In AC analysis the results are complex When plotting a curve from an AC analysis the magintude of the complex data is plotted unless some other explicit function is applied such as phase or imag Although the magintude of the data is plotted the graph system retains the original complex values So any arithmetic operation performed directly on complex plotted data will also be complex For example if you have two curves from an AC analysis and you choose the Plot Subtract Two Curves menu to subtract them the new result will be the magnitude of the complex difference not the difference in the magnitides as might be expected In mathematical terms you will see la bl not lal Ibl Using Random Probes in Hierarchical Designs Random probes may successfully be employed in hierarchical designs There are however some complications that arise and these are explained below Closed Schematics Read the following if you find situations where cross probing inside hierarchical blocks sometimes fails to function 243 User s
162. al Parameter Description Interval Time taken to ramp from start frequency to end frequency Peak Peak voltage Offset Offset voltage Points Per Cycle Minimum number of time steps in each sinusoidal cycle Increasing this number will improve the accuracy of the simulation at the expense of simulation speed Bidirectional Pulse Generates a symmetrical bidirectional pulse waveform Use menu Place Voltage Sources Bidirectional Pulse then place device in the usual way Editing the device will bring up a dialog with 3 parameters Parameter Description P P Voltage Peak to peak voltage Frequency Pulse frequency Delay Delay after start Analysis Modes 50 Overview In this section we explain how to setup the most commonly used analysis modes in both SIMetrix and SIMPLIS SIMetrix SIMPLIS product only For more comprehensive details on analysis modes see Analysis Modes on page 174 for SIMetrix and SIMPLIS Analysis Modes on page 206 for SIMPLIS Using the Choose Analysis Dialog Analysis mode is setup by selecting the menu SimulatorlChoose Analysis In SIMetrix mode this displays the following dialog box Chapter 3 Getting Started r Transient AC DC l Noise TF SOA Options Analysis Mode E Transient Transient parameters ie Stop time eee DC Sweep Data output options Noise Start data output 0 V Defaut P anier pinc
163. algorithms work and what their limitations are All the measurement algorithms are implemented by internal scripts The full source of these scripts can be found on the install CD see Install CD on page 16 per Cycle and Frequency Measurements These measurements assume that the curve being analysed is repetitive and of a fixed frequency The results may not be very meaningful if the waveform is of varying frequency or is of a burst nature The cycle measurements calculate over as many whole cycles as possible Each of these measurements use an algorithm to determine the location of x axis crossings of the waveform The algorithm is quite sophisticated and works very reliably The bulk of this algorithm is concerned with finding an optimum base line to use for x axis crossings The per cycle measurements are useful when the simulated span does not cover a whole number of cycles Measurements such as RMS on a repetitive waveform only have a useful meaning if calculated over a whole number of cycles If the simulated span does cover a whole number of cycles then the full version of the measurement will yield an accurate result Rise and Fall Time and Overshoot Measurements These measurements have to determine the waveforms pulse peaks A histogram method is used to do this Flat areas of a waveform produce peaks on a histogram The method is very reliable and is tolerant of a large number of typical pulse artefacts such as ring
164. alone E g amplifier sxcmp This allows the schematic file and component file to be moved together to any location but they may not be moved individually In general we recommend using relative paths wherever possible The exception is when placing a comonent that is held in a general library for example a standard cell used in an integrated circuit design To place a component using its full path Select schematic menu HierarchylPlace Component Full Path Select a component file then place in the normal way To place a component using its relative path Select schematic menu Hierarchy Place Component Relative Path Select a component file then place in the normal way Using symbolic constants SIMetrix has a facility to define path names using symbolic constants This system allows absolute locations for files to be defined using a single value and thus making it easy to change that location See Symbolic Path Names on page 351 for further details Windows Linux Interoperability From version 5 5 paths are stored on each schematic instance using the UNIX directory separator that is the forward slash This allows schematics created using a Windows version to be used with a Linux version which was not possible in earlier versions that used a back slash In most cases Windows accepts a forward slash as a directry separator whereas Linux does not accept a back slash Connecting Busses in a Hierarchy Overview
165. alue in data If xEnd is specified Y2 y value at xEnd otherwise Y2 minimum y value in data XatNthyY XatNthY data yValue n Returns the x value of the data where it crosses yValue for the nth time 295 User s Manual XatNthYn XatNthYn data yValue n Returns the x value of the data where it crosses yValue for the nth time with a negative slope XatNthYp XatNthYp data yValue n Returns the x value of the data where it crosses yValue for the nth time with a positive slope XatNthYpct XatNthYpct data yValue n As XatNthY but with yValue specified as a percentage of the maximum and minimum values found in the data YatX YatX data x Value Returns the y value of the data at x value xValue YatXpct As YatX but with xValue specified as a percentage of the total x interval of the data Data Import and Export 296 SIMetrix provides the capability to export simulation data to a file in text form and also to import data from a file in text form This makes it possible to process simulation data using another application such as a spreadsheet or custom program SIMetrix may also import data in SPICE3 raw file format and CSDF format Some other simulation products can output in one or both of these formats Importing SPICE3 Raw and CSDF Files 1 Select command shell menu File DatalLoad 2 In Files of type select SPICE3 Raw Files or CSDF Files as required 3 Select file to import SIMetrix will rea
166. am sxsch 183 User s Manual 10k 10k Rs R4 Outpit amp AT Probe 5V ae Vi Q12 Q13 AC1 0 l1 V3 20u restail restail R1 R2 5V v2 Q1 Q2 OsuB This is a simple long tailed pair The above circuit resistors R1 and R2 have been given the values restail restail is a parameter that is swept in an AC sweep to plot the gain of the amplifier vs tail resistance at 100kHz Here is the result of the run D 100k o simple differential amplifier Output V 100 200 400 1k 2k 4k 10k restail 184 Chapter 7 Analysis Modes Note that this analysis mode is not available in standard SPICE or the majority of its derivatives Most offer parameter sweeping but only for DC analysis Frequency Sweeps frequency for the small signal analysis modes namely AC AC Noise and Transfer Function In standard SPICE it is the only sweep mode available for AC and Noise while Transfer Function can not be swept at all Monte Carlo Repeats analysis point for a specified number of times with device tolerances enabled The following graph show the result for the same circuit as shown above but with restail 1k and with a 1000 point Monte Carlo AC sweep This run takes a fraction of a second on any modern machine Distribution of gain 100KH for 1000 samples Output V
167. an empty graph sheet The menus ProbelVoltage New graph sheet ProbelCurrent New graph sheet will always create a new graph Chapter 9 Graphs Probes and Data Analysis Functions The following table shows all available random probe functions Many of these can be found in the schematic s Probe menu while others are only available from ProbelMore Probe Functions Function Single Ended Voltage Single Ended Voltage AC coupled Single Ended Voltage dB Single Ended Voltage Phase Single Ended Voltage Fourier Single Ended Voltage Nyquist Single Ended Voltage Normalised dB Single Ended Voltage Group delay Differential Voltage Differential Voltage dB Differential Voltage Phase Differential Voltage Fourier Differential Voltage Nyquist Differential Voltage Normalised dB Differential Voltage Group delay Relative Voltage dB Relative Voltage Phase Relative Voltage Nyquist Relative Voltage Normalised dB Relative Voltage Group delay Single Ended Current In device pin Single Ended Current AC coupled in device pin Single Ended Current In wire Single Ended Current dB Single Ended Current Phase Single Ended Current Fourier Single Ended Current Nyquist Single Ended Current Normalised dB 229 User s Manual 230 Function Single Ended Current Group delay Differential Current Actual Differential Current dB Differential Current Phas
168. arning may be ignored at this point Creating Schematic for Block 1 Select the symbol whose schematic you wish to define then select schematic menu HierarchylDescend Into Note the symbol must have been saved as a component as described above 2 Anew schematic sheet will be opened with a number of module port symbols already placed These will be named according to the pin names of the block You must use these to make connections to the outside world 73 User s Manual Bottom up method Creating Schematic 1 Open or draw schematic It must have at least one Module Port symbol on it To place a module port use schematic menu Hierarchy Place Module Port 2 Save the schematic as a component Select menu Save As then select Components from Save as type list Creating Symbol for Schematic 1 Select HierarchylOpen Create Symbol for Schematic 2 A graphical symbol editor window will be opened with a default symbol generated from the number orientation and names of the module ports on the schematic 3 The symbol created can be saved straight away or you can edit it to suit your requirements To save it in the symbol editor window select the menu FilelSave You will not usually need to change any of the settings in the dialog Just press Ok to close Navigating Hierarchical designs There are a number of means of navigating hierarchical designs You can go up or down one level or you can jump straight to the
169. art Hamming 1 Blackman Data Span Usually the entire simulated time span is used for the fourier analysis To specify a smaller time interval click Specify and enter the start and end times Note that if you specify a fundamental frequency the time may be modified so that a whole number of cycles is used This will occur whether or not you explicitly specify an interval Window A window function is applied to the time domain signal to minimise spectral leakage See above The choice of window is a compromise The trade off is between the bandwidth of the main spectral component or lobe and the amplitude of the side lobes The rectangular window which is in effect no window has the narrowest main lobe but substantial side lobes The Blackman window has the widest main lobe and the smallest side lobes Hanning and Hamming are something in between and have similar main lobe widths but the side lobes differ in the way they fall away further from the main lobe Hamming starts smaller but doesn t decay whereas Hanning while starting off larger than Hamming decays as the frequency moves away from the central lobe Despite the great deal of research that has been completed on window functions for many applications the difference between Hanning Hamming and Blackman is not important and usually Hanning is a good compromise There are situations where a rectangular window can give significantly superior results This requires tha
170. at is created on a graph For example with the following graph 249 User s Manual J PSU Waveforms Selected aa File Edit Cursors Annotate Curves Axes View Measure Plot PIRQAAJ o MMM EBATE R m L3 P v R5 N tran5 I L3 P 1 94 1 96 1 98 2 2 02 2 04 2 06 2 08 Time kSecs 20Secs div x 2 01643kSecs y 31 1214A Tf you attempt to delete the selected axis the lower one nothing will happen Instead you should move the two curves in the top axis to the lower one See above section on how to move curves Editing Axes You can edit axis scales label and units by selecting the graph popup menu Edit Axis This brings up the following dialog box 250 Chapter 9 Graphs Probes and Data Analysis J Edit Axis ra Axis Labels X Axis Y Axis Lin Log Auto Lin Log Auto Nochange No change Auto scale Auto scale Defined Defined Min i Min 430 033 Max 2 08294 Max 31 1214 The function of the Axis scales sheet and axis labels sheet is similar to the sheets of the same name in the define curve dialog box See Plotting an Arbitrary Expression on page 238 for details Reordering Grids and Digital Axes You can change the vertical order of the analog grids and digital axes To change the analog grid order 1 2 Select AxeslReorder Grids You will be presented with a list of currently displayed grids identi
171. at it is used in preference to the FFT in such situations The continuous Fourier technique has the additional advantage that it can be applied with greater confidence as the aliasing errors will not be present It does have its own source of error due to the fact that simulated data itself is not truly continuous but represented by unevenly spaced points with no information about what lies between the points This error can be minimised by ensuring that close simulation tolerances are used See the Convergence and Accuracy chapter of the Simulator Reference Manual for details Because each frequency component is calculated individually the calculation time is affected by the values entered in Frequency Display See below Plot Phase or Magnitude The default is to plot the magnitude of the Fourier spectrum Select Phase if you require a plot of phase or dB if you need the magnitude in dBs Frequency Display Resolution Hz Available only for the continuous Fourier method This is the frequency interval at which the spectral components are evaluated It cannot be less than 1 T where T is the time interval over which the spectrum is calculated Start Freq Hz Start frequency of the display Stop Freq Hz Stop frequency of the display Log X Axis Check this to specify a logarithmic x axis This will force a minimum value for the start frequency equal to 1 T where T is the time interval being analysed Chapter 9 Graphs Probes and
172. at revnnn pdf Linux nnn is the format revision number Important The schematic will be saved in binary format as long as the following are satisfied 1 The ASCII format check box is not checked if using the Save Special menu 2 The file being saved does not already exist OR the file does exist and is not already a SIMetrix ASCII schematic So if you have an ASCII schematic and wish to convert it to binary the only method is to open it normally then save to a new file Autosave When enabled SIMetrix will automatically save all open schematics at regular intervals This system does not write to the schematic s normal file but to a backup location If SIMetrix closes unexpectedly due perhaps to a power failure you will be asked whether you would like to recover the auto saved schematics when you restart SIMetrix To enable auto saving and to set the auto save interval select menu File Options General See the Auto save interval section in the Schematic sheet Creating Schematic Symbols Overview 82 A large variety of schematic symbols are supplied with SIMetrix which should cover many uses However there will be occasions when you wish either to define your own new symbol perhaps to implement a hierarchical block or subcircuit or to modify one of the standard symbols This section describes how this can be done There are two different methods to create symbols 1 Use the graphical symbol editor see pag
173. at the start of each run and this seed value is displayed in the log file It is also possible to fix the first seed that is used using the SEED option This makes it possible to repeat a run To do this note the seed value of the run of interest from the log file then set the seed as follows 1 Select schematic menu SimulatorlChoose Analysis 337 User s Manual 2 Select Options tab and enter the seed value in the Monte Carlo section The first run of each Monte Carlo analysis will use the same random values as the run from which you obtained the seed value in the log file Note this assumes that only changes in values are made to the circuit Any topology change will upset the sequence This technique is a convenient way of investigating a particular run that perhaps produced unexpected results Obtain the seed used for that run then repeat with the seed value but doing just a single run You will then be able to probe around the circuit and plot the results for just that run Analysing Monte Carlo Results 338 Plots Plots of Monte Carlo analyses are performed in exactly the same manner as for normal runs When you probe a circuit point curves for each run in the MC analysis will be created You will notice however that only one label for each set of curves will be displayed Operations on curves such as deleting and moving will be performed on the complete set Identifying Curves Sometimes it is useful to know exact
174. ations If this happens you may wish to increase the minimum time or reduce the measurement window as appropriate Periodic Operating Point POP Periodic Operating Point POP finds a steady state operating point of switched systems that are periodically driven or self oscillating The predominant application of this analysis mode is to rapidly find the settled condition of a switching power supply without having to simulate the entire power up sequence This dramatically speeds up the analysis of design s behaviour under different load conditions For further details of POP analysis see the SIMPLIS Reference Manual Setting up a POP Analysis 1 Select menu SimulatorlChoose Analysis 2 Select POP check box on the right 209 User s Manual 210 3 Select POP tab at the top Triggering r Use POP Trigger schematic device Trigger gate Trigger conditions Oto 1 1tod Conditions Max period tu Cycles before pg launching POP See menu Place gt Analog Functions gt POP Trigger AC Transient 0 0 Advanced Enter parameters as described in the following sections POP Parameters Triggering Use POP Trigger Schematic Device Trigger gate Trigger Condition Conditions Max period POP analysis requires a trigger signal to indicate the start of each periodic cycle The best way to define this is using a special schematic component To place this select menu Plac
175. ator command window F11 is active Space bar definitions must always be shifted The same codes can be used for menu short cuts See DefMenu command page 311 Key definition will be lost when SIMetrix is exited To make a key or menu definition permanent you can place the command to define it in the startup file To do this select command shell menu FilelScriptslEdit Startup and add the line above Examples To define control R to place a resistor on the schematic sheet enter the command DefKey CR inst res 4 The built in definition for F12 to zoom out a schematic is DefKey F12 SCHEM zoom out 4 This definition only functions when a schematic is active A similar definition for F12 GRAPH zooms out a graph when a graph window is active DefMenu DefMenu immediate shortcut key_code menuname command_string when_to_enable Defines custom menu The above is not complete and there are more optional switches available Full documentation is available in the Script Reference Manual immediate Immediate mode Command is executed immediately even if another operation such as a simulation run or schematic editing operation is currently in progress For other options the command is not executed until the current operation is completed Only a few commands can be assigned with this option See DefMenu command documentation in the Script Reference Manual for full details 311 User s Manual 312 shortcut key_code menuna
176. ause the file created is a script To run the plot journal you will of course first need to run a simulation or load previous data so that the journal has some data to work with The plot journal itself does not store any data With the simulation data you wish to work with in place select either graph menu PlotlRun Plot Journal or command shell menu GraphlRun Plot Journal This simply runs a script located in the current directory Note that the plot journal always creates a new graph sheet Graph Layout Multiple Y Axis Graphs 246 Graphs may have additional Y axes to accommodate plotting results with incompatible scales This occurs particularly for plotting dB and phase against each other and also for voltage and current The additional Y axes may either be superimposed or stacked In the user interface and the remainder of this documentation these are referred to respectively as Axes and Grids These are illustrated below Chapter 9 Graphs Probes and Data Analysis File Edit Cursors Annotate Curves Axes View Measure Plot PAQAQ S XM HME E BAER E F sip Y1 F L3 P Y2 tran5 1 P Y1 196 198 2 202 204 206 208 21 212 Time kSecs 20Secs div x 2 11322kSecs y 3 43892A Current and Voltage plotted on separate Axes 247 User s Manual 248 File Edit Cursors Annotate Curves Axes View Measure Plot ic QAAJ S xA HAE E Ra TR a a ye S1 P Y1
177. aximum and each point either side then calculating the x y location of the point with zero slope If noInterp is specified the peak values are those found in argument without any interpolation The vector returned by this function has an attached reference which contains the x values of the maximum points If xSort is not specified the vector is arranged in order of descending y values i e largest y value first smallest last Otherwise they are organised in ascending x values Maximum real complex real real Start x value End x value Returns the largest value found in the vector in the interval defined by start x value and end x value If the vector is complex the operation will be performed on the magnitude of the vector mean real complex Returns the average of all values in supplied argument If the argument is complex the result will also be complex Chapter 11 Command and Function Reference Mean1 real real real Start x value Default start of vector End x value Default end of vector Returns the integral of the supplied vector between the ranges specified by arguments 2 and 3 divided by the span arg 3 arg 2 If the values supplied for argument 2 and or 3 do not lie on sample points second order interpolation will be used to estimate y values at those points minidx real complex Returns index of the array element in argument with the smallest magnitude Minima real real string
178. bably more interested in the average power dissipation over a specified time To display the average power dissipation over the analysis period 1 Select menu MeasurelMean This should display a value of about 517mW This is the average power over the whole analysis period of 1mS You can also make this measurement over any period you select using the cursors as described below t Zoom in the graph at a point around 100uS i e where the power dissipation is at a peak Switch on graph cursors with menu CursorslToggle On Off There are two cursors represented by cross hairs One uses a long dash and is referred to as the reference cursor the other a shorter dash and is referred to as the main or measurement cursor When first switched on the reference cursor is positioned to the left of the graph and the main to the right Position the cursors to span a complete switching cycle There are various ways of moving the cursors To start with the simplest is to drag the vertical hairline left to right As you bring the mouse cursor close to the vertical line you will notice the cursor shape change See Graph Cursors on page 254 for other ways of moving cursors Press F3 or select analysis menu MeasurelMore Functions J Define Measurement Pre defined Measurement Custom Measurement Pre process Choose measurement W Cursor span Custom RMS M megraicyces C F AC coupled Maximum Minimum
179. be changed If checked the listing of expanded subcircuits will be output to the list file This is sometime useful for diagnosing problems Controls the level of model and device parameter output to the list file Options are None No Output Brief Only values defined by an expression are output Given The default Values that are explicitly defined are output Full All parameter values are output including defaults Seed for pseudo random number generator used to generate random numbers for tolerances See Multi step Analyses on page 200 If Enable check box is unchecked a seed value will be chosen by the simulator Verilog HDL Options This section will only show if Verilog HDL simulation is available for your version of SIMetrix Open console for Verilog process When the Verilog simulator runs a console window in Windows or terminal window in Linux will displayed showing any output messages from the simulator See Open Console for Verilog Process on page 344 for 199 User s Manual details Verilog simulator Simulator that will be used to run Verilog HDL See Verilog Simulator on page 343 for details Timing resolution Time resolution in Verilog simulator See Timing Resolution on page 343 for details Multi step Analyses 200 The analysis modes Transient AC DC Noise and Transfer Function can be setup to automatically repeat while varying some circuit parameter Multi s
180. been seen as slow and prone to inaccuracies stemming from imperfect models In recent years however the simulation of discrete analog circuits has become more viable This has come about because of the almost relentless advances in CPU power the increased availability of device models from their manufacturers and the introduction of easy to use and affordable simulation tools such as SIMetrix The pressure to reduce product development time scales has meant that for many projects the traditional bread boarding phase is skipped altogether with or without simulation and circuit development is carried out on the first revisions of PCB The use of simulation on a circuit or parts of a circuit can help to eliminate errors in a circuit design prior to this stage and reduce the number of PCB revisions required before the final production version is reached Of course to be useful the simulation process must therefore not be too time consuming Computer simulation does however have many more uses There are some things you can do with a simulator which cannot be achieved with practical approaches You can remove parasitic elements you can make non invasive measurements that are impossible in real life or you can run components outside of their safe operating area These abilities make simulation a valuable tool for finding out why a particular design does not behave as expected If the problem can be reproduced on a simulator then its cause can be
181. cal schematics whereas NODELIST omits these Has two options map If present will order the nodes according to the MAPPING property nox If present will disable XSpice pin attributes See Adding XSpice Pin Attributes on page 87 for details PINLIST lt PINLIST gt Replaced by the symbol s pin names NODE lt NODE n gt Replaced by the individual node identified by n starting at 1 So node 1 is node name connected to the first pin on the symbol Chapter 4 Schematic Editor MAPPEDNODE lt MAPPEDNODE n gt Same as NODE except that the mapping property is applied The mapping property is used to rearrange nodes in a different order than defined on the symbol It is used by the model symbol association system to allow a single symbol to be associated with multiple models that may not necessarily have the same terminal order INODE lt INODE name gt Resolves to a unique node number that is guaranteed not be used anywhere else The value name may be used to identify the number for repeated use within the same TEMPLATE For example lt inode a gt will always resolve to the same node number if used more than once within the same TEMPLATE definition INODE is intended to be used to create devices that need multiple netlist lines with connected nodes This can also be done using a subcircuit but for simple cases INODE may be more convenient PINNAMES lt PINNAMES gt Equivalent to PINNAMES lt PINLIST gt exc
182. can reassign component references so that they are allocated by their position on the schematic To do this select menu Edit Assign References By Position Checking the Schematic The schematic menu SimulatorlCheck performs a number of checks First a netlist of the circuit is created During this process the following potential errors will be reported Unconnected pins Dangling wires Implicit connections e g two terminal symbols with the same name Name translations This is for busses with different names connected together One name has to win Shorted components Any components with two or more pins which have all their pins connected to each other Next the netlist is read in by the simulator but the simulation is not started This will identify any devices for which models have not been found Schematic Preferences Component Toolbar The default toolbar show a selection of symbols useful for either CMOS IC design Micron versions or discrete circuit design all other versions There are however many more buttons available and these can be added as desired To do this select the schematic menu ViewlConfigure Toolbar This will display a dialog box allowing full customisation of the component buttons on the schematic toolbar Note that the 71 User s Manual toolbar configuration in SIMetrix mode is independent of the configuration in SIMPLIS mode Further customisation of all toolbars is possible
183. challenging task and imposes some tradeoffs between timing precision and simulation speed In particular circuits where a digital section sits inside an analog feedback loop are especially demanding As SIMetrix is an analog tool for analog designers we have focussed on providing maximum accuracy This imposes the need for rapid communication between the analog simulator and the Verilog simulator and for this we have developed our own inter process communication method as the standard system supplied techniques were too slow Documentation In this chapter we show how to use the Verilog HDL simulation feature using the schematic editor Reference documentation for the underlying simulator device that implements the Verilog HDL interface can be found in Chapter 4 of the Simulator Reference Manual see Verilog HDL Interface VSXA Supported Verilog Simulators For Windows versions we supply two alternative open source Verilog simulators namely GPL Cver Pragmatic C Software and Icarus Verilog Stephen Williams These simulators are installed and configured ready to use For Linux only the GPL Cver simulator is supplied Icarus Verilog has been tested successfully but we do not currently supply it due to installation difficulties The configuration of the external simulator is user definable and other VPI compliant simulators can be setup As previously mentioned Mentor Graphics ModelSim is fully supported Basic Operation To
184. chnique used to speed the search for models and subcircuits It is completely transparent and requires no action from the user SIMetrix creates an index file for each library specification it encounters either installed globally or referenced using LIB This index files contain details of the file locations of models and subcircuit definitions referenced by the library specification These index files can then be used for later simulation runs to speed the search for models and subcircuits Index files are automatically rebuilt if any of the library files referenced are modified Modifications are detected by comparing file dates All index files are stored in app_data_dir INDEXES where app_data_dir is the location of the application data directory See Application Data Directory for the location of this directory The files are named SXn sxidx where n is some number Note that if you add a new model file to a directory while SIMetrix is running SIMetrix won t know of the new file and any relevant indexes won t be updated In this situation select the menu FilelModel LibrarylRebuild Catalog to update the indexes Duplicate Model Names Models of some common parts are available from different sources Sometimes these have different names e g LF356 and LF356 NS the latter available from the National Semiconductor library In some cases the model names from different sources are identical This poses a problem as models have to be uniqu
185. cing a Single Pin To place a single pin select Property Pin Place Pin Place this on the sheet by left clicking the mouse at your desired location Note that pins always snap to major grid points See diagram in section Symbol Editor Window on page 83 The first pin you place on the sheet will be called pin The signifies that the pin name will not be visible when the symbol is placed on a schematic Editing Pin Attributes To edit the attributes of the pin e g to change its name or visibility select either the pin or its label with the left mouse key then press F7 or select popup menu Edit Property Pin Atrc This will display the following dialog J Edit Pin rx Pinname 8 Text Location Justification Left Baseline Pin name will be hidden 7 Hidden H atic ly Text will be rotated Vertical by 90 Attributes Font style Default Pin name Must be unique within the symbol and may not contain spaces 85 User s Manual 86 If the symbol is to be used as a hierarchical block the pin name must match the names of the module ports on the schematic which it represents If the symbol is to be used for an existing sub circuit from for example a model library the pin names are not important and you can choose any suitable name The pin names do not need to match the node names in the sub circuit definition Text Location Justification If the pin name is visible this specifies i
186. cking on each 2 Select menu Monte CarlolSet Selected Component Tolerances and enter tolerance in the dialog box You may use the symbol here if you wish so 5 and 0 05 have the same effect Note this is the only place that is recognised you can t use it netlists or models Chapter 12 Monte Carlo Analysis Tf all the resistors or all the capacitors in a circuit are to have the same tolerance select either Monte CarlolSelect All Capacitor Tolerances or Monte CarlolSelect All Resistor Tolerances Device tolerances can be applied to the following components Capacitors Resistors Inductors Fixed voltage sources Fixed current sources Voltage controlled voltage sources Voltage controlled current sources Current controlled voltage sources Current controlled current sources Lossless transmission lines applied to ZO parameter Device tolerance will be ignored for other devices Model Tolerances Refer to the Simulator Reference Manual for full details Matching Devices Some devices such as resistor networks are constructed in a manner that their tolerances track Such devices often have two specifications one is an absolute tolerance and the other a matching tolerance A thin film resistor network might have an absolute tolerance of 1 but a matching tolerance of 0 05 This means that the resistors will vary over a 1 range but will always be within 0 05 of each other To specify matched devices fo
187. cr script that builds the menu system on program start or you can make additions by adding commands to the start up script 2 Using the GUI based menu editor The first method offers the ultimate in flexibility but has a steep learning curve The second method is quite simple to use and is appropriate for simple changes to the menu system such as deleting unused menus or changing hot key definitions The following describes the second method For details about the first method please refer to the Script Reference Manual 301 User s Manual 302 Procedure Select menu File Options Edit Menu This will open the following dialog box J Edit Menu Syste ee Menu Name Accelerator 4 fg Command Shell E Schematic W Simplis Schematic E Schematic Popup Remove E SimplisSchematic Context ns E Symbol Editor Add Separator E Symbol Editor Popup Graph Popup Add Menu Graph ee Add Item Edit item Accelerator Reset Hint Use Add Item to restore items deleted using Remove The above view shows the layout for SIMetrix SIMPLIS products For SIMetrix only products the top level menu choices will be slightly different The left hand pane shows the current menu system in a tree structured list The buttons on the right allow you to move delete or add new menu items and sub menus To Delete a Menu Item or Entire Sub menu Select the item you wish to del
188. cribed in Full Model Installation Procedure on page 163 This will make the device globally available to all schematics You can also install it into the parts browser system These topics are covered in Device Library and Parts Management on page 162 and are also the subject of Tutorial 3 To place the device on the schematic find the symbol in schematic popup All Symbols and place in the normal way After it is placed select the device and press shift F7 and enter the subcircuit s name If you installed the device into the parts browser system as mentioned in choice 4 above you will be able to place the device by pressing control G and selecting the device from the appropriate category The parts browser system also provides a simple to use means of overcoming the problem mentioned above that occurs if the symbol s Chapter 5 Components pin order does not match the subcircuit s node order This is explained Associating Multiple Models with Symbols on page 167 Passing Parameters You can pass parameters to a subcircuit This subject is covered in detail in the Simulator Reference Manual To specify the parameters for a sub circuit device in a schematic you must enter the values manually using shift F7 Enter the values after the subcircuit name E g suppose you wished to specify the parameters FREQ 12k Q 15 To enter these select the sub circuit press shift F7 and append the sub circuit name with FREQ 12
189. ct a symbol from the drop down box or press Auto Create Symbol to create a new one AD587 f selecting an existing symbol you must make Pin order 4 sure that the pin order matches the model k definition shown below Press Help for assistance ff you use Auto Create Symbol the pin order will not need to be changed 3 First specify a suitable category for the device In this case it is an operational amplifier so select Op amps from the drop down box labelled Choose Category for SXOA1000 4 Next define a symbol for this part Under Define Symbol for SXOA1000 select Operational Amplifier 5 terminal We have not quite finished yet Our new op amp has the wrong pin out for the schematic symbol The pin order for the symbol is shown in the third box down on the right and is as follows 39 User s Manual Pin name INP INN VSP VSN OUT The text at the bottom of the dialog box shows the actual subcircuit definition Fortunately it has been annotated with the function of each of the sub circuit s Function Non inverting input Inverting input Positive supply Negative supply Output terminals This is in fact usually the case with third party models As you can see the output terminal is in the wrong place We can change the pin order using the Pin order up and down buttons 1 Select out in the pin order box 2 Click twice on the up button s
190. cute more than one command Scripts SIMetrix features a comprehensive scripting language Full details of this can be found in the Script Reference Manual This is available as a PDF file on the install CD see Tnstall CD on page 16 and may also be downloaded from our web site Command Line Editing The command line itself is a windows edit control The cursor keys home and end all work in the usual way You can also copy control C cut control X and paste control V text There is also a right click popup menu with the usual edit commands Command Line Switches Many commands have switches These are always preceded by a and their meaning is specific to the command There are however four global switches which can be applied to any command These must always be placed immediately after the command and before any command specific switches Global switches are as follows e Forces command text to copied to command history ne Inhibits command text copying to command history quiet Inhibits error messages for that command This only stops error message being displayed A script will still be aborted if an error occurs but no message will be output noerr Stops scripts being aborted if there is an error The error message will still be displayed Editing the Menu System Overview The menu system in SIMetrix may be edited by one of two methods 1 Using the script language You can either edit the menu sxs
191. d If you wish to access an old run use FilelLoad Data and retrieve the data from the TEMPDATA directory created under the SIMetrix install directory The file will have the same name as the group appended with SXDAT Whether or not the data file is still available depends on a preference setting See Graph Probe Data Analysis on page 359 for details Combining Results from Different Runs There are occasions when you wish to say plot the difference between a node voltage for different runs You can do this in SIMetrix using the Probe Add Curve menu by entering an expression such as vector vector2 in the y expression box where vector and vector2 are the names of the signals However as the two signals come from different runs we need a method of identifying the run This is done by prefixing the name with the group name followed by a colon The group name is an analysis type name tran ac op dc noise tf or sens followed by a number The signal name can be obtained from the schematic For voltages move the cursor over the node of interest and you will see the name appear in the status box in the form NET For currents put the cursor on a device pin and press control P The group name is displayed in the simulator progress box when the simulation is running You can also find the current group by selecting Graphs and Datal Change Data Group and noting which group is highlighted in the dialog box Here is
192. d as for SPICE For example a device with a model property of value Q will always be a BUT regardless of its component reference model properties of X H and F have a special significance as follows X Subcircuit instance pinnames specifier will be added to inform simulator of the devices pin names The simulator will then choose names for device current vectors which will allow cross probing of currents from the schematic F Current controlled current source The standard SPICE CCCS is a two terminal device which uses a separate voltage source for the controlling current SIMetrix provides the facility to use a single four terminal device with pins 3 and 4 for the controlling current and pins 1 and 2 for the output Any symbol with four terminals and a model property of F will be treated as a such a device An additional voltage source will be created by the netlist generator and connected to pins 3 and 4 to be used as the controlling current H Current controlled voltage source As F above but has a voltage output For a list of valid device types and their signifying letters see Summary of Simulator Devices on page 115 In some respects the special behaviour of model property values X F and H is legacy from the past The recommended method of customising netlist output is to use the template property but this was not supported in very early versions of SlMetrix User s Manual Pro
193. d Voltage E 1 p output Source 2 n output 3 cp control 4 cn control Voltage Source V 1 p output 2 n output Subcircuits X Pins can be given any name Numbering must be in the order that pins appear in the subckt control which defines the subcircuit SlMetrix uses a special extension of the netlist format to tell the simulator what the pin names are Verilog A device U Pin count names and order must recomme match ports in Verilog module nded statement See Verilog A User Manual for details VSXA Verilog HDL device U Pin count names and order must match ports in Verilog module statement See VSXA device in the Simulator Reference Manual AC Table Lookup U Pin count 2 x number of ports This device does not currently provide current readback Pin names can thus be assigned arbitrarily 117 User s Manual Chapter 5 Components Overview In this chapter we describe the components available at the schematic level Broadly speaking components fall into two categories namely numbered and generic Numbered components are devices that have a manufacturer s part number and are described by a model either supplied with SIMetrix or by the manufacturer itself Generic components are devices that are defined by one or more parameters that are entered by the user after the component has been placed on the schematic A transistor like a 2N2222 or BC547 is an example of a numbered component and a resistor is probab
194. d as you type in the user name This can usually be left alone The symbol created will be empty Use the symbol editor to define it You can call this directly by clicking the Edit button Note that this will close the library manager dialog box Placing Symbol If a schematic sheet is open you can place a symbol on it directly from the library manager by clicking the Place button Note that this will close the dialog box Editing System Symbol Libraries The system symbol libraries are listed in the file SystemLib sxIst located in the symbol libraries folder The libraries are treated specially when written to e g when editing any symbol in the library System symbol libraries are protected from being edited directly You can still edit the system symbols but the changes are stored separately in an ASCII file located in a directory in the application data area This scheme protects such changes from being lost when the system symbol libraries are updated during a service update The system symbol libraries are stored in a directory defined by the SymbolsDir option variable see page 378 On Windows this is typically located at C Program Files SIMetrixXX support symbollibs and on Linux usr local simetrix_xx share symbol libs The directory where system library edits are stored is defined by the UserSystemSymbolDir option variable see page 380 PSpice Schematics Translation 110 SIMetrix can read schematic files created by the
195. d from the sampled data if the sampling rate is greater than twice the maximum frequency component in the signal In practice this condition can never be met perfectly and any signal components whose frequency is greater than half the sampling rate will be aliased to a different frequency So if the number of interpolated points is too small there will be errors in the result due to high frequency components being aliased to lower frequencies This is the Achilles heel of FFTs 233 User s Manual 234 applied to simulated data The Continuous Fourier technique described next does not suffer from this problem It suffers from other problems the main one being that it is considerably slower than the FFT Continuous Fourier This calculates the Fourier spectrum by numerically integrating the Fourier integral With this method each frequency component is calculated individually whereas with the FFT the whole spectrum is calculated in one quite efficient operation Continuous Fourier does not require the data to be interpolated and does not suffer from aliasing The problem with continuous Fourier is that compared to the FFT it is a slow algorithm and in many cases an FFT with a very large number of interpolated points can be calculated more quickly and give just as accurate a result However in cases where a signal has a very large high frequency content such as narrow pulses this method is superior and it is recommended th
196. d in the Script Reference manual for more details SimDataGroupDelete Text Default Never No Same as DataGroupDelete see page 367 when simulator is run independently l e not called from the front end SIMPLISComponentButtons Text As ComponentButtons but Schematic for SIMPLIS operation Toolbar menu SIMPLISPath Text Default EXEPATH sim No plis exe Path of SIMPLIS binary SnapshotExtension Text Default sxsnp File extension used for snapshot files StartUpDir Text Current directory set at Options start of session dialog StartUpFile Text Default Startup SXSCR_ Options Script that is automatically dialog run at start of each session StatusUpdatePeriod Numeric Default 0 2 seconds No Minimum delay in seconds between updates of simulator status window during run 377 User s Manual Name Type Description User interface support SymbolExtension SymbolMainButtons SymbolsDir TempDataDir TerminalEmulator TextExtension TotalVectorBufferSize 378 Text Text Text Text Text Text Numeric Default sxslb slb File extension used for symbol files See Chapter 7 Script Reference Manual Creating and Modifying Toolbars for details Default SHAREPATH Option SymbolLibs dialog Path of directory where system symbol libraries are located Default TEMPPATH Options SIMetrixTempData dialog See Default Configuration Location on page 355 for definition
197. d see a series of curves build up as the run progresses Tolerances and Distribution Functions Distribution Functions Tolerances are defined using distribution functions For SIMPLIS Monte Carlo there are just three functions available These are defined below Function Name Description GAUSS tol Returns a random with a mean of 1 0 and a standard deviation of tol 3 Random values have a Gaussian or Normal distribution UNIF to Returns a random value in the range 1 0 to witha uniform distribution WC tol Returns either 1 0 to or 1 0 to chosen at random The L and E suffix functions available in S Metrix Monte Carlo analysis are not available for SIMPLIS operation Lot and Device Tolerances No special provision has been made to implement so called Lot tolerances which model tolerances that track However it is nevertheless possible to implement Lot tolerances by defining a parameter as a random variable Suppose for example that you have a resistor network consisting of 4 resistors of 1k with an absolute tolerance of 2 but the resistors match to within 0 2 The absolute tolerance is the lot tolerance This is how it can be implemented ja Assign a random variable using the VAR preprocessor control You cannot use PARAM in SIMPLIS simulations E g VAR rvl UNIF 0 02 B Give each resistor in the network a value of 1k ew UNIF CO 0027 rv1 will be updated on
198. d startup ini On Windows this must be located in the same directory as SIMetrix exe On Linux the file must be located at HOME simetrix startup ini The format of the file is as follows StartUp settings settings can be any combination of the following StartupScript startup_script equivalent to s on command line UsePrevInst equivalent to i on command line InhibitSplash equivalent to n on command line ConfigLoc config_location equivalent to c on command line Features features equivalent to f on command line Configuration Settings Overview SIMetrix in common with most applications needs to store a number of values that affect the operation of the program These are known as configuration settings Included among these are the locations of installed symbol libraries installed model libraries font preferences colour preferences and default window positions Default Configuration Location By default SIMetrix stores configuration settings in a single file This file is located at simetrix_app_data_dir config Base sxprj windows simetrix_app_data_dir config Base sxprj linux See Application Data Directory below for location of simetrix_app_data_dir Application Data Directory SIMetrix stores a number of files in its application data directory On the Linux platform this is at one of the following locations 355 User s Manual 356 HOME simetrix ver full production versions HOME si
199. d the entire file and write its data out to a temporary sxdat file in the same way as it does when saving its own simulation data The data read from the raw file is buffered in RAM in order to maximise the efficiency of the saved data SIMetrix will use up to 10 of system RAM for this purpose Note that this feature is not available with SIMetrix Intro Chapter 9 Graphs Probes and Data Analysis Importing Tabulated ASCII Data SIMetrix can import data in a tabulated ASCII format allowing the display of data created by a spreadsheet program There is a no menu for this but this can be done using the OpenGroup command page 313 with the text switch E g at the command line type OpenGroup text data txt This will read in the file data txt and create a new group called textn See Data Files Text Format on page 298 below for details of format Note that if you create the file using another program such as a spreadsheet the above command may fail if the file is still open in the other application Closing the file in the other application will resolve this Exporting SPICE3 Raw Files SIMetrix can export all simulation data to a SPICE3 raw file This format may be accepted by third party waveform viewers To export a SPICE3 raw file proceed as follows 1 Select menu FilelDatalSave 2 Under Save as type choose SPICE3 Raw Files Note that various applications use slightly different variants of this format By de
200. d to any primitive model or subcircuit In this method the SPICE device is measured using the SIMetrix simulator in a number of test circuits Chapter 5 Components The results of these tests are then analysed and used to derive the final SIMPLIS model SPICE to SIMPLIS conversion takes place when you place the device on the schematic and may be repeated if you edit one of the additional parameters see below If Simulated parameter extraction is being used the message Extracting SIMPLIS model for Please wait will be displayed For MOSFETs this process usually takes less than about 0 5 seconds on a modern machine but can be much longer if the SPICE model is complex Note that Simulated parameter extraction is not guaranteed to succeed and can fail if the SPICE model is faulty or badly designed Additional Parameters Semiconductor devices converted for SIMPLIS operation have some additional parameters that may be edited after the device is placed This is done using the popup menu Edit Additional Parameters The parameters displayed depend on the type of device but usually include some parameters to define operating conditions These are used to work out suitable coordinates for the piece wise linear approximation needed for SIMPLIS devices in order to extract the most efficient and accurate model Some device have a LEVEL parameter which defines the complexity of the model used to set the trade off between accuracy and speed
201. d with markers even for colour printers Options dialog Default 1 Minimum suffix used for automatic generation of schematic component references Default False Only effective if AutoWireEnabled is False Selects mode whereby a wire is started when the cursor is brought close to a pin or wire termination This mode is on automatically when AutoWireEnabled is True Options dialog Default True Smart wiring is on if this is True Options dialog Default True Options Controls whether the smart dialog wire algorithm is allowed to route wires through existing wires that connect to the destination or target Chapter 14 Sundry Topics Name Type Description User interface support AxisPrintWidth Numeric Default 0 5 Options Width of printed axis in dialog mm See also CurvePrintWidth and GridPrintWidth BiasAnnoPrecision Numeric Default 6 Options Precision of values dialog displayed for schematic DC bias annotation BiScriptDir Text This is the first location that Options SIMetrix searches for dialog scripts See File Locations section of options dialog above for more info BuildAssociations Text Default ask See Auto Configuration Options on page 383 BuildModelLibs Text Default ifempty See Auto Configuration Options on page 383 BuildPreferenceSettings Text Default askmigrate See Auto Configuration Options on page 383 BuildSymbolLibs Text Default ifempty See Auto Con
202. defined in the above graph Default value for threshold is Ymax Ymin 2 Where Ymax largest value in data and Ymin in smallest value in data Implemented by built in script uf_duty Source may be obtained from the install CD see Install CD on page 16 Fall Fall data xStart xEnd A Y1 Amplitude V y2 Function returns the 10 to 90 fall time of the first falling edge that occurs between x1 and x2 The 10 point is at y threshold Y1 Y2 Y1 0 1 and the 90 point is at y threshold Y1 Y2 Y1 0 9 Tf xStart is specified X1 xStart otherwise X1 x value of first point in data If xEnd is specified X2 xEnd otherwise X2 x value of last point in data Chapter 9 Graphs Probes and Data Analysis If xStart is specified Yl y value at xStart otherwise Y1 maximum y value in data If xEnd is specified Y2 y value at xEnd otherwise Y2 minimum y value in data Implemented by built in script uf_fall Source may be obtained from the install CD see Install CD on page 16 Frequency Frequency data threshold Finds the average frequency of data Returns n 1 X x1 Where n the number of positive crossings of threshold x the x value of the nth positive crossing of threshold x the x value of the first positive crossing of threshold If threshold is not specified a default value of ymax ymin 2 is used where ymax is the largest value in data and ymin is the smallest value Im
203. desueasshtsesenectescccarsesuseasertaeecnes 249 Stacking Curves to Multiple Grids cece 249 Moving Curves to Different Axis or Grid 249 User s Manual 10 Deleting Axes Editing Ax S 2 i sits beh avd lien Reordering Grids and Digital AxeS eeeeeee 251 Plotting the Results from a Previous Simulation 251 Combining Results from Different Runs 252 Curve Operations ecceeceseeeeeseeeeeeeeeeeseeeeeeeeeneeeeeeenaees 253 Selecting Curves ccecceseceeeeeeeneeteeeeeeeeeteeeeeeteaeens 253 Deleting CUIVES cceccceeceeeseeeseeeeeeeeeeteaeeeeeeneeeeas 253 Hiding and Showing Curves 253 Re titling CUES eeeeeeeeseeteeeeeeeeeeeeteneeteaeeeaeeeee 254 Highlighting Curves eeceeeeeeeeeeeeeeeeteeeeeneeeneeees 254 Graph Cursors 2hcike aden Gas bee eet 254 OVGIVIEW ec cess cccteetietes hectes i ir a 254 Cursor Operations ecceeeceseceeeeeeseeeeeeeeeneeeeeeeeaees 255 Additional CUrSOIS eeceeseeeeeeeeeeeeeeeneeteeeeneeesees 257 Cursor Radot ina a a 257 C rsor F NC ONS pelii naaie a e 259 Curve Measurements eceeeceeeeeeeteeeeeeeeneetieeeeeeeeees 260 OVENVIEW ars och hleciteee ener 260 Available Measurements 260 Using the Define Measurement GU 055 260 Measurement Definitions Manager eee 262 Repeating the Same Measurement 000 264 Applying Measurements to Fixed Probes 264 No
204. e Monte Carlo and Multi step Analysis See page 200 See Also NOISE in Simulator Reference Manual Plotting Results of Noise Analysis Refer to Plotting Noise Analysis Results on page 231 Chapter 7 Analysis Modes Example 1 Frequency Sweep USUB The result of a noise analysis on the above circuit using a frequency sweep 100 40n 20n 10 Output Noise V rtHz 4n 2n im 10 100 1k 10k 100k 1M 10M 100M 1G Frequency Hertz 191 User s Manual Example 2 Noise with a Parameter Sweep In the following circuit we wish to find the optimum value of tail current for a source impedance of 1KQ To do this we sweep the parameter taili which is used to set the current as well as the values for R1 R2 R3 and R4 As can be seen from the graph about 3004A would seem to be best The noise analysis was setup with the following parameters Sweep parameter taili from 11 to 10m 25 points per decade Output node VPos Reference node VNeg Input source V3 sourceR 1000 set with PARAM control 1 taili 5 1 taili 5 R3 R4 5V v1 _ VPos VNeg sourceR X sourcet re n 1 taili 50 om R2 AC1 0 5V v2 USUB The result 192 Chapter 7 Analysis Modes Input referred noise while sw eeping tail current Frequency 1K sourceR 1K Input Noise V rtHz iu 10u 10
205. e Differential Current Fourier Differential Current Nyquist Differential Current Normalised dB Differential Current Group delay Power Impedance Output noise noise analysis only Input noise noise analysis only Device noise noise analysis only Arbitrary expressions and XY plots Notes on Probe Functions Impedance You may plot the AC impedance at a circuit node using ProbelMore Probe Functions This only works in AC analysis This works by calculating V I at the device pin selected Device Power Device power is available from ProbelPower In Device This works by calculating the sum of VI products at each pin of the device Power is not stored during the simulation However once you have plotted the power in a device once the result is stored with the vector name device_name pwr E g if you plot the power in a resistor R3 its power vector will be called R3 pwr You can use this as part of an expression in any future plot Note that because SIMetrix is able to find the current in a sub circuit device or hierarchical block it can also calculate such a device s power Be aware however that as this power is calculated from the VI product of the device s pins the calculation may be inaccurate if the sub circuit uses global nodes Chapter 9 Graphs Probes and Data Analysis Plotting Noise Analysis Results Small signal noise analysis does not produce voltage and current values at nodes and in devices in th
206. e Press the Wire button again to cancel this mode Disconnecting Wires In most cases just selecting the wire then deleting it with the delete key or button is the easiest way In some cases especially if the wire is short it is difficult to select it In this instance hold down the shift key then select area enclosing the wire Press delete button To Move Items Disconnected Select items then schematic menu EditlDetach or the Detach toolbar button Move items to desired location then press left mouse key You can rotate flip mirror the items see above while doing so To Copy Across Schematics Select block you wish to copy Choose menu EditlCopy In second schematic choose EditlPaste Multiple Selection Individual items which do not lie within a single rectangle can be selected by holding down the control key while using the mouse to select the desired items in the usual way Chapter 3 Getting Started Selecting Wires Only Hold down shift key while performing select operation Holding Down the ALT Key While selecting will limit component selection to only devices that are wholly enclosed by the selection box Zoom Area Press the Zoom box button on schematic Drag mouse to zoom in on selected area Zoom Full Fit to Area Press the HOME key to fit the whole schematic in the current window size Circuit Rules The following design rules must be observed for the simulation to run correctly Note that
207. e command window manually Stage 2 Netlist Circuit To create a subcircuit netlist select schematic menu Simulator Create Netlist as Subcircuit You will be first be prompted for a subcircuit name This name will also be used for the file name with extension MOD After entering the name you will be asked to specify the subcircuit pin order J Select subcircuit pin order INP OUT VSN VSP When you close this box the subcircuit will be created and its text will be displayed Calling a Sub circuit in a Schematic To call a sub circuit in a schematic you must choose or create a symbol for it The symbol must have the same number of pins and ideally it would also have the same pin order In other words the order of the nodes in the SUBCKT line would be the same as the pin order of the symbol The matching of SSUBCKT node order and symbol pin order is not absolutely essential but it makes things much easier If they are not the same there is method of overcoming the problem using the mapping property This is explained in the section Properties on page 94 Creating symbols for the schematic is covered in Creating Schematic Symbols Overview on page 82 The symbol must have the following properties see page 94 155 User s Manual 156 Property Property value Purpose name Model X Ensures netlist line starts with X Identifies component as a subcircuit Should be hidden and
208. e corrected within the PSpice environment before reading the file into SIMetrix Using Schematic Editor for CMOS IC Design 112 MOSFET Symbols 4 MOSFET symbols are supplied for use in CMOS IC design These are Chapter 4 Schematic Editor Q2 N channel 3 terminal bulk to VSS nmos_a3_vss_new 4 W 1u L fu nmos_a_new W 1u L 1u Q1 N channel 4 terminal 4 Q3 P channel 3 terminal bulk to VDD pmos_a3_vdd_new J W 1u L 1u Q4 P channel 4 terminal pmos_a_new J W 1u L 1u In the Micron versions of SIMetrix these will by default be available from the component toolbar These symbols have the model name N1 for the N channel types and P1 for the P channel types These names can of course be changed after being placed on the schematic but this would be time consuming to have to do each time To avoid having to do this you can do one of the following Modify your SPICE model files so the devices are always called N1 and P1 Modify the standard symbol so the model name corresponds to your SPICE models Create a new set of symbols for each process you use The best course of action is probably to create a new symbol for each process Once you have created the new symbols you can modify the toolbar buttons so that they call up your new symbols instead of the standard ones You must do this using the DefButton command which redefines toolbar buttons To make permanent changes the DefButton command should be put in the s
209. e 83 2 Create manually with a script Chapter 4 Schematic Editor For most applications using the graphical symbol editor is the most appropriate method Creating a symbol from a script is appropriate for automated symbol creation Details are provided in the Script Reference Manual Graphical Symbol Editor Notes The graphical symbol editor shares much in its operation and layout with the schematic editor For this reason it is recommended that before learning how to use the symbol editor you become competent in the operation of the schematic editor In some parts of the following sections the explanations assume that you are already familiar with the schematic editor Symbol Editor Window The following diagram shows the main elements of the symbol editor Rotate mirror flip Zoom box outiin Draw segment tool Duplicate Detach Cut Major grid point p lt Device pins always snap to these Minor grid point Lines arcs and circles snap to these More minor grid points come into view with higher magnification Internal symbol name The Elements of a Symbol Schematic symbols are composed of a combination of the following elements All symbols that represent an electrical device would comprise all of these elements 83 User s Manual 84 Symbols used purely for annotation would not need pins and may not need one or other of the remaining elements either The schematic
210. e Vector Graphics svg This is a relatively new format and is not supported by many applications However it is the only scalable format available in Linux 3 Bitmap default image size png jpg bmp These are available on all platforms are widely supported by graphics applications but these are not scalable formats and so do not offer good quality when printed using high resolution printers PNG is the default format if you do not choose a file extension PNG tends to be the most efficient format to use for images such as schematics and it is also lossless meaning that it uses a compression technique which does not lose information To choose JPG JPEG format or BMP windows bitmap format you must explicitly enter jpg or bmp file extensions respectively With this option the image size will match the image size currently displayed on screen If you wish to specify a different image size use next option 4 Bitmap specify image size png jpg bmp As 3 above but you must explicitly define the image resolution in pixels You will be prompted for this when you close the file selection dialog box Note that schematics always maintain their aspect ratio so the final image size may differ from what you specify The actual image will always fit within the X and Y values you give Exporting to Earlier Versions of SIMetrix The schematic format used from version 4 1 onwards has been designed in a manner that allows us to add new fea
211. e first in the list is the default So for example the default schematic extension is sxsch so when you save a schematic without giving an extension it will automatically be given the extension sxsch Data Files Extensions used for simulation data files Device catalogs Extension for device catalogs used by parts browser system Device models SPICE model files Used by drag and drop system to detect model file types Note the drag and drop system will detect model files with extensions not in this list and it is not usually necessary to specify model file types here Logic Def Files Files used for logic definitions for the digital simulator s arbitrary logic block If the extension is omitted in the model FILE parameter this will be used Schematic Components Chapter 14 Sundry Topics Extensions used by schematic component files Schematic Files Extensions used for schematic files Scripts Default extension for scripts if called without an extension Symbol Files Extension used for binary schematic symbol files This is used by the drag and drop system to detect Symbol Library files being dropped into the command shell Text files Supported extensions for text files FilelScriptslEdit File will list all files with these extensions Using the Set and Unset commands All options have a name and many also have a value These are set using the Set command page 315 and can be cleared with UnSet page 316 When an option is clea
212. e found in the Edit Additional Parameters menu For devices that do not have user editable initial conditions you should use the Edit Additional Parameters menu This applies to most subcircuit models and to all hierarchical blocks How Does it Work The initial condition file specifies the value of initial conditions for each device that requires them This information must then be applied to each schematic instance in an appropriate manner Two basic approaches are used to apply the initial condition values depending on the device namely the specialised method and the generic method In the specialised method a special script is called which edits one or more properties of the schematic instance With a capacitor for example the VALUE property is edited so that the IC parameter is specified or modified Something similar is done for 219 User s Manual 220 inductors This action is done using a special script specified by the INIT_SCRIPT property In the case of the capacitor the script ic_reactive is called The advantage of the specialised method is that the device can be modified in a manner that is consistent with its existing user interface Capacitors already have user editable initial conditions and the application of back annotated initial conditions is compatible with this The disadvantage of the specialised method is that a method of applying the back annotated value needs to be developed for every different typ
213. e frequency radio button will be enabled Chapter 7 Analysis Modes Sweep mode Step parameters 5 Device Start value 1k Parameter Stop value 2k 5 Mode parameter Number of steps Jt Temperature q Monte Caro List Snapshot Parameters Device name Parameter name Enter parameter as described below Only the boxes for which entries are required will be enabled In the above example only the Number of steps box is enabled as this is all that is required for Monte Carlo mode Sweep Mode Choice of 6 modes as described above Step Parameters Define range of values If Decade is selected you must specify the number of steps per decade while if Linear is specified the total number of steps must be entered If List is selected you must define a sequence of values by pressing Define List Group Curves Curve traces plotted from the results of multi step analyses will be grouped together with a single legend and all in the same colour For Monte Carlo analysis this is compulsory for other analyses it is off by default Parameters The parameters required vary according to the mode as follows 201 User s Manual 202 Mode Parameters Device Device name e g V1 Parameter Parameter name Model Parameter Model name Model parameter name Temperature None Frequency not DC or transient None Monte Carlo None Snapshot See Transient Snapshots on page 179 Example 1 Refer to circuit
214. e is also used to determine the data output interval if Output at PRINT step is specified see above Real Time Noise See page 193 Monte Carlo and Multi step Analysis See page 200 Advanced Options Opens a dialog as shown below 177 User s Manual 178 J Transient Advanced Options E Time step Max time step 2 E Defaut Min time step 20f S F Defaut Integration method Miscellaneous Trapezoidal integration F Skip DC bias point Gear integration Fast start The simulation will run 0 6 V Defaut at higher speed but less precision up to this time Time Step The simulator always chooses the time step it uses but it will not rise above the maximum time step specified here If the simulator needs to use a time step smaller than the minimum specified the simulation will abort Reduce this value if the simulation aborts with the message Time step too small This might happen for long runs on circuits that have very small time constants Integration Method Set this to Gear if you see an unexplained triangular ringing in the simulation results Always use Trapezoidal for resonant circuits A full discussion on integration methods is given in the Convergence and Accuracy chapter of the Simulator Reference Manual Skip DC bias point If checked the simulation will start with all nodes at zero volts Note that unless all voltage and current sources are specified to have zero output at tim
215. e made to the schematic tool bar The diagram above shows the standard toolbar and the function of each button To Place a Component If it is a simple device which only needs a value such as a resistor or capacitor select the appropriate symbol from the tool bar or Place menu For other devices that require a part number it is easiest to use the parts browser Select menu PlacelFrom Model Library and select your desired device Once the symbol has been selected using the mouse move the image of the component to your desired location then press the left mouse button This will fix the component to the schematic Depending on preference settings command shell menu FilelOptions General schematic tab you may now be presented with another copy of the symbol for placement Use left key as before to place press right key to cancel Selecting a Single Component Most operations require items to be selected When an item component or wire is selected it changes colour to blue To select a single component just left click it Selecting an Area To select all items within a rectangular area of the schematic press the left mouse key in an empty area of the sheet and hold down while dragging mouse to opposite corner of rectangle A rectangular box should be drawn as you move the mouse Note that if the initial cursor position is too close to a wire junction or component a move operation will be carried out instead of selection 63
216. e menu as SIMetrix but you must first set the schematic to SIMPLIS mode See Simulation Modes SIMetrix or SIMPLIS on page 42 for details Select menu SimulatorlChoose Analysis You will see the following dialog box 7 15 Analysis AC Transient Select analysis POP Triggering AC Use POP Trigger schematic device See menu Place gt Analog Functions gt POP Trigger Transient Tri ate a Save options Trigger conditions Oto 1 1to0 Al Voltages Only Conditions Probes Only Max period 1u S Cycles before 5 m launching POP Advances No Forced Output Data E Force New Analysis SS GS Gea Ge SIMPLIS has three analysis modes namely Transient Periodic Operating Point POP and AC Transient is similar to SIMetrix transient analysis POP is a unique analysis mode that finds the steady state of a switching circuit AC finds the small signal response of a periodic system Transient Analysis To setup a basic transient analysis 55 User s Manual 56 1 Click on the Transient tab Periodic Operating Point AC Analysis parameters Stop time 1m pan i 0 S E Defaut Plot data output aa 0 S E Defaut i a im S E Defaut en ik S E Defaut Advanced 2 Check the Transient box in the Select analysis section 3 Enter an appropriate stop time under Analysis parameters 4
217. e mouse cursor close to either an unselected symbol pin or an unselected wire end As you do this you will notice that the cursor changes shape to depict a pen symbol 2 Click the left button press and release to mark the starting point of the wire connection 3 Move the cursor to the destination point This may be anywhere on the schematic not just at a wire end or symbol pin If there is a viable route from the start point to the destination point SIMetrix will locate it and draw the wire route Smart Wiring Notes The smart wiring algorithm use an heuristic algorithm that finds as many routes as possible then chooses the best one based on a number of criteria The criteria used in the selection include the number of corners the number of wires crossed the number of property labels crossed and its overall length It attempts to find the most aesthetically pleasing route but as this is somewhat subjective it may not necessarily find the route you may have chosen manually However in our tests we have found that it usually finds the best route for situations where there are no more than 2 or 3 corners required In developing the algorithm we paid particular attention to common scenarios found in analog design such as routing the output of an opamp back to its inverting input and you should find that these common scenarios work well Smart Wiring Options There is two option to control the smart wiring algorithm Firstly you ca
218. e of circuit You will still get sensible results without checking this option they will just be a little better with it For more information see Convergence and Accuracy chapter in the Simulator Reference Manual If you have any graph windows open you should now close them Once you have loaded or entered the circuit press F9 or use the schematic Simulator Run menu to start the simulation This will take somewhat longer than the previous tutorial but still less than 1 second on a modern machine This is the graph you will see Chapter 2 Quick Start 0 t 1 3 g 2 O 3 4 0 0 2 0 4 0 6 0 8 1 Time mSecs 200uSecs div The circuit is the switching stage of a simple step down buck regulator designed to provide a 3 3 V supply from a 9V battery The circuit has been stripped of everything except bare essentials in order to investigate power dissipation and current flow Currently it is a little over simplified as the inductor is ideal More of this later We will now make a few measurements First the power dissipation in Q1 1 Create an empty graph sheet by pressing F10 2 Select schematic menu ProbelPower In Device Left click on Q1 This is what you should see 201 IW x Power Q1 0 0 2 0 4 0 6 08 1 Time mSecs 200uSecs div 33 User s Manual This shows a peak power dissipation of 200W although you are pro
219. e of device This would not be acceptable for most users who develop their own symbols The generic method overcomes this difficulty The generic method modifies the properties so that additional netlist lines are created containing the INIT simulator command that defines the initial conditions To achieve this the SIMPLIS_TEMPLATE property needs to be modified and as long as this isn t protected the generic method will always work Hierarchical Blocks and Subcircuits All back annotated initial conditions are applied at the top level and no child schematics or subcircuits will be modified This introduces a potential problem in that once back annotated initial conditions are applied you will no longer be able to modify individual initial conditions within a hierarchical block You will only be able to edit them on the top level device using the Edit Additional Parameters menu You will be able to use initial conditions defined within a hierarchy or subcircuit if you first disable top level initial conditions using the Initial Conditions Disable menu This will of course disable all initial conditions specified at the top level To disable initial conditions for a single hierarchical block use the Edit Properties menu to set the USEIC property to 0 Note that the Enable and Disable menus will reset this property Chapter 9 Graphs Probes and Data Analysis Chapter 9 Graphs Probes and Data Analysis Overview The basics of how
220. e status bar instead of or as well as the on graph dimension display Select menu Cursors Display Options and select option as required This will change the current display You can opt to have this preference used as the default Select command shell menu FilelOptions General then Graph Probe Data Analysis tab Select appropriate option in Cursor readout section Note that the readout for additional cursors is always on the graph there is no option to display in the status bar Show Curve Info The menu Cursors Show Curve Info will display in the command shell information about the curve which currently has the main cursor attached The following information is listed Curve name Source group The name of the simulation group that was current when the curve was created Curve id Only required when accessing curves using script commands Run number If there are multiple curves generated by a Monte Carlo run this is a number that identifies the run number that created the curve This number can be used to plot the curve alone and also to identify the seed value used for that Monte Carlo step Cursor Functions There are four functions which return the current positions of the cursors and these can be used in script expressions These are XDatum YDatum XCursor YCursor See Script Reference Manual for details This is available as a PDF file on the install CD see Install CD on page 16 and is also availab
221. e to power Only integral powers may be specified Constants Any decimal number following normal rules SPICE style engineering suffixes are accepted S Variable This can be raised to a power with or by simply placing a constant directly after it with no spaces E g s 2 is the same as s2 Filter response functions These are described in the following table Function Syntax Filter Response BesselLP order cut off Bessel low pass BesselHP order cut off Bessel high pass ButterworthLP order cut off Butterworth low pass ButterworthHP order cut off Butterworth high pass ChebyshevLP order cut off Chebyshev low pass passband_ripple ChebyshevHP order cut off Chebyshev high pass passband_ripple Where order Integer specifying order of filter There is no maximum limit but in practice orders larger than about 50 tend to give accuracy problems cut off 3dB Frequency in Hertz passband_ripple Chebyshev only Passband ripple spec in dB Using Parameters with Laplace Devices Currently it is not possible to use parameters defined with PARAM in Laplace expressions You can however use parameters in the underlying simulator device if you define the expression in terms of the numerator and denominator coefficients Chapter 5 Components Refer to the S domain Transfer Function Block in the Simulator Reference Manual for further details Arbitrary Non linear Passive Devices Each of these will place a compo
222. e way that AC DC and transient analyses do Noise analysis calculates the overall noise at a single point and the contribution of every noisy device to that output noise Optionally the input referred noise may also be available To Plot Output Noise 1 Select menu Probe AC NoiselPlot Output Noise To Plot Input Referred Noise 1 Select menu Probe AC NoiselPlot Input Noise Note that you must specify an input source for input referred noise to be available See Noise Parameters on page 190 for details To Plot Device Noise 1 Select menu Probe AC NoiselProbe Device Noise 2 Click on device of interest Note that noise results are only available for noisy devices such as resistors and semiconductor devices Plotting Transfer Function Analysis Results No cross probing is available with transfer function analysis Instead you must use the general purpose Define Curve dialog box With this approach you must select a vector name from a list Proceed as follows 1 Select menu ProbelAdd Curve 2 Select a value from the Available Vectors drop down box Transfer Function Vector Names The vector names for transfer function will be of the form source_name V gain source_name Transconductance source_name Transresistance source_name l gain where source_name is the name of a voltage or current source The vectors Zout Yout or Zin may also be available These represent output impedance output admittance and input impedance res
223. e zero the simulation may fail to converge if this option is specified Fast start The accuracy of the simulation will be relaxed for the period specified This will speed up the run at the expense of precision This is a means of accelerating the process of finding a steady state in circuits such as oscillators and switching power supplies Its often of little interest how the steady state is reached so precision can be relaxed while finding it Chapter 7 Analysis Modes Note that the reduced precision can also reduce the accuracy at which a steady state is found and often a settling time is required after the fast start period Restarting a Transient Run After a transient analysis has run to completion that is it has reached its stop time it is still possible to restart the analysis to carry on from where it previously stopped To restart a transient run 1 Select the menu SimulatorlRestart Transient 2 In the New Stop Time box enter the time at which you wish the restarted analysis to stop Press Ok to start run See Also TRAN in Simulator Reference Manual Transient Snapshots Overview There is often a need to investigate a circuit at a set of circuit conditions that can only be achieved during a transient run For example you might find that an amplifier circuit oscillates under some conditions but these conditions are difficult or impossible to create during the bias point calculation that usually prec
224. each Monte Carlo step but will always have the same value in each place where it is used Monte Carlo Seed Values Introduction The random values used in Monte Carlo analysis are generated using a pseudo random number generator This generates a sequence of numbers that appear to be random and Chapter 8 SIMPLIS Analysis Modes have the statistical properties of random numbers However the sequence used is in fact repeatable by setting a defined seed value The sequence generated will always be the same as long as the same starting seed value is used This makes it possible to repeat a specific Monte Carlo step as long as the seed value is known SIMetrix SIMPLIS explicitly sets a random seed value at the start of each Monte Carlo run and records this in a file A facility exists to explicitly set the seed value instead of using a random seed and this makes it possible to repeat a specific step This is useful in cases where one or more Monte Carlo steps show unexplained behaviour and further investigation is needed This is also useful if you wish to find the values of the components used for a particular Monte Carlo step Finding the Seed Value To find the seed value of a particular step follow this procedure 1 Run normal Monte Carlo without seed definition if you have not done so already 2 Find the run number of the result whose seed you require so that you can repeat that step You can find the run number from a plotted wave
225. eate new empty symbols ready for editing with the symbol editor Chapter 4 Schematic Editor Operations Installing Libraries Select the Add button and select a library file to install Note that if you have the PSpice translator option you can install PSpice symbol libraries SLB files directly See PSpice Schematics Translation on page 110 for more details Clicking the Add button will open a file select dialog box but note that it has two additional buttons at the top left called User and System Clicking these buttons will take you straight to the user symbols directory and the system symbols directory respectively Uninstalling Libraries Select the library file you wish to uninstall from the Library Files box then click the Remove button Note that this does not delete the file Changing Search Order When searching for a particular symbol the library files are searched in the order in which they are listed in the Library Files box To change the order use the Up and Down buttons Moving Symbols To move an individual symbol to a new category simply pick it up with the mouse and drop it onto the new category You can move a symbol to a new library by dropping the symbol onto a library file in the Library Files box You can move more than one symbol at a time by picking up a complete category Copying Symbols To copy a symbol within a library select the symbol in the Symbols box then click the Copy button
226. eck box at the right and the DC tab at the top You will need to enter some values in the Sweep Parameters section Transient AC oc Noise TF soa Options Sweep parameters Start value 0 a oh cas Decade Stop value 5 a Linear Number of points 50 o Device name Mode Device Define The analysis will sweep the device you specify in the Device name box over the range specified by Start value Stop value and Number of points or Points per decade if you select a decade sweep The entry in the Device name box is the component reference of the device to be swept and for DC sweep would usually be a voltage source a current source or a resistor Device sweep is just 1 of 5 modes available with DC sweep The Define button allows you to specify one of the others See DC Sweep on page 186 for details AC Frequency Sweep An AC Frequency Sweep calculates the small signal response of a circuit to any number of user defined inputs over a specified frequency range The small signal response is computed by treating the circuit as linear about its DC operating point There must be at least one input source for AC analysis for the results to be meaningful Connect a voltage or current source to the circuit select it then press F7 In the dialog box select the Enable AC check box On the circuit an AC input voltage source will look something like this AC 1 0 al To set up an AC Frequency Sweep select the AC check box a
227. ed 1 a Reverse recovery specification Capacitance IF Forward curent 1 a G0 Capacitance at zero bias 100p IRM Peak reverse current 500m S Save options ais Save to schematic symbol Reco i m y ve dna 5 Save to model library Parameters define a soft recovery characteristic Tris the time to recover to 37 of the peak Device name reverse current from the zero crossing crea 2 Enter the required specification in the DC Forward bias spec Reverse recovery specification and Capacitance sections See below for technical details of these specifications 3 Select Save to schematic symbol if you wish to store the specification and model parameters on the schematic symbol This will allow to you to modify the specification later If you select Save to model library then the definition will be written to a library file and installed in the parts library This will make the new model available as a standard part but you will not be able to subsequently modify it other than by re entering the specification manually If you choose this option you must specify a device name in the box below 4 Press Ok to place diode on the schematic If you selected Save to model library the model file for the device will also be created at this point The file will be saved in your user models directory On windows this is located at My Documents SIMetrix Models and on Linux it is at HOME simetrix Models Soft Rec
228. ed In the Snapshot mode box select one of the three options Write bias info to list file Instructs the simulator to write the DC operating point data to the list file Does not save snapshot data Save state for AC TF Noise analysis Instructs the simulator to save snapshot data only No bias point information will be output to the list file Write bias info and save state Performs both operations described in 1 and 2 above Creating Snapshots on Demand You can create a snapshot of a transient run after it has started by executing the SaveSnapShot script command Proceed as follows 1 Pause the current transient analysis or allow it to finish normally You must not abort the run as this destroys all internal simulation data Type at the command line the edit box below the menu bar in the command shell window SaveSnapShot That is all that is needed You can now start a new small signal analysis using the snapshot created Applying Snapshots to a Small Signal Analysis 1 2 3 4 Select menu SimulatorlChoose Analysis Select AC TF or Noise analysis Press Define Multi step Analysis for the required analysis mode Select Snapshot mode The analysis will be repeated for all available snapshots Chapter 7 Analysis Modes Important Note Snapshot data can only be applied to an identical circuit to the one that created the snapshot data So you must make sure that any components needed for a small signal ana
229. ed as a greek pin graph axis labels 379 User s Manual Name UseNativeXpSplitters UserCatalog unsupported UserScriptDir UserSymbolsDir UserSystemSymbolDir UseSmallGraphCursor 380 Type Boolean Text Text Text Text Boolean Description Default false The standard splitter bar in windows XP is flat and usually not visible In some SIMetrix windows the standard style has been bypassed in order to make these visible For example the legend panel in graphs Set this option to true to revert to standard XP behaviour You may need to use this if using a non standard XP theme Default sxappdatapath user_v2 Location and base name without extension of the user catalog file Alternative location for user scripts See Script Reference Manual for more information Path of directory where the user s symbol libraries are stored Default sxappdatapath SysSymbols Location of symbol libraries containing edits to system symbols Default false If true a small graph cursor will be used instead of the full crosshair User interface support No No No Options dialog No Cursors Cursor Style Chapter 14 Sundry Topics Name Type Description User interface support VertTextMode ViDataPath VIModuleCacheSize WarnSubControls WireWidth WorkingCatalog unsupported Text Text Numeric Boolean Numeric Tex
230. edes a small signal AC analysis Transient snapshots provide a solution to this problem The state of the circuit at user specified points during a transient run may be saved and subsequently used to initialise a small signal analysis The saved state of the circuit is called a snapshot Snapshots can be created at specified intervals during a transient run They can also be created on demand at any point during a transient run by first pausing the run and then manually executing the save snapshot command So for example if you find your amplifier reaches an unstable point during a transient analysis you can stop the analysis save a snapshot and then subsequently analyse the small signal conditions with an AC sweep An option is also available to save the DC operating point data to the list file at the point at which snapshots are saved Defining Snapshots Before a Run Starts 1 Select menu SimulatorlChoose Analysis 2 Inthe Transient Sheet select button Define Snapshots 3 You will see the following dialog 179 User s Manual 180 J Define Snapshots Snapshot locations Snapshot mode i Start time 100u a Write bias info Linear sequence to list file S top time 1m a E Save state for f m vi Z Sinterval 100u S AC TFD Noise analysis N Write bias info stone Define List and save state CEJ Ga Ge Select either Linear sequence or List to define the time points at which the snapshots are sav
231. eees 209 Setting up a POP Analysis cccscceesseeeeteees 209 AG Analys Siouan etait ai ates 212 Setting up an AC AnalySis ccccsccceeseeeeetees 212 SIMPLIS Options sci snosi aeia aa chee ake 213 Multi step and Monte Carlo Analyses ceeeeeee 213 OVOIWICW 22 re carana ranie noc dees eE R ewes tees 213 Comparison Between S IMetrix and SIMPLIS 214 Setting up a SIMPLIS Multi step Parameter Analysis214 Setting Up a SIMPLIS Monte Carlo Analysis 215 Tolerances and Distribution Functions 216 Monte Carlo Seed Values eeceeseeseeeeeteeneeee 216 Performance Analysis and Histograms 218 Table of Contents Initial Condition Back annotation cccceeeeeeseeees 218 Ove NEW eos hs ieee al ees 218 How to Back annotate a Schematic cee 219 Disable Enable Initial Conditions cccceeees 219 Back annotation Errors ccccccccccccececeesseesseeeeeens 219 Editing Back annotated Initial Conditions 219 How Does it Work 00 ecccccccccceeeceeeseeseseeesesesereees 219 Hierarchical Blocks and Subcircuits 0008 220 Chapter9 Graphs Probes and Data Analysis Elements of the Graph Window ccessesseeeeeeeeeeees 221 Main Window iieii aeaaea 221 Windows and Tabbed Sheets cccseeeereeees 221 Graph Toolbar 2 5 cote ea oes 222 Probes Fixed VS Random esceessseeeeeneeeee
232. ees 128 Saturable Inductors and Transformers 130 Ideal Transformers ccesseeeeneeesneeeeeneeeeeneteneaes 132 Coupling Factors ccnsk fence ted adit 133 Mutual INGUCtOIS 0 ec eeeeeeeeeeeneeeeeneeeteneeeeeneeeee 133 Resistors Capacitors and Inductors 0 000 134 Infinite Capacitors and Inductors 135 Potentiometer sus s canister teneesiins 136 Lossless Transmission Line n 136 Lossy Transmission Line 137 Fixed Voltage and Current SOUICES eeeeee 137 Controlled SOUrCES cceceeeeeeeeeseeeeneeeneeeeeeeeeees 137 Voltage Controlled Switch ceeeeeeeeeeeeeeeneees 138 Switch with Hysteresis ceeceeseeeeeseeeeeeeeneees 138 Delayed Switch ec ceeceeeseeeseeeeaeeeneessaeeeseeeneeeees 139 Parameterised Opamp ecsceeseeeeeeeeneeseeeeeeeeeaes 140 Parameterised Opto Coupler cccsceeeeeeeeeees 141 Parameterised Comparator ccceecceeeceeeteeeeeees 141 N CQ a cigs are caine els headend 142 Verilog A Library 2 eeeeeesteeesneeeeeneeeeeneeeeenneeeeeees 142 Generic ADCs and DACS ececceeeceeeeeeeeretereeeeees 144 Generic Digital Devices ee eeeeeeeeeeeeeeteeenees 145 Functional Blocks OVervieW cceeceeteeereeeee 145 Non linear Transfer FUNCTION eeeeeeeeeeeeeneeees 146 Laplace Transfer Function n se 148 Arbitrary Non linear Passive Devices 151 Creating Models ceecceesesseeeeeeeeteeeeeeeenee
233. eets c cceeeeeeee 62 Schematic Editor Window ccceeeeceeseeeeeeeeeeees 62 Editing Operations cceeceeseeseeeeeeeeseeeeeeeenreeaes 63 WIIG Pane EEE EE E E E E EEE E 67 EditiModes 4 8 c 40 2A ea ed 69 BUS Connections ae aa rarene E n iei iakat 69 Copying to the Clipboard seeeeeeeseeeeeeeeeeeeeeeeee 70 Annotating a Schematic 0 00 ee eeceeseeeeeteeeeeeeeteeees 70 Assigning Component References ccseeeeee 71 Checking the Schematic cceseeeeeeeeeeeeeeeteetens 71 Schematic Preferences cccceeceeeeeseeseeeneeeeeeeee 71 Adding and Removing Worksheets 72 Finding and Specifying Net Names eeee 72 Hierarchical Schematic Entry c cccsceeeeeeeeeseeeeteees 72 Top Down Method eeeeeceeeeneeeseeeeesneeeteneeeeeneeees 73 Bottom up Methd eeeeeeeseeeeeneeeeeneeeeeneeeeeenneeneaes 74 Navigating Hierarchical designs 74 Placing Full vs Relative Path ascen 74 Connecting Busses in a Hierarchy ceeeeeeee 75 Global Nets pinnien aa ne ee 76 Global Pins sis 222 sec dese cecest E ET 76 Passing Parameters Through a Hierarchy 78 Missing Hierarchical Blocks seeen 79 Highlighting piisaa Gila antes eice Copying a Hierarchy PrintNet aaa eh esd Ric eae Printing a Single Schematic Sheet ceeeee 80 Printing a Hierarchical Schematic cceeeeees 80 File Op rationS ecen nnm iene nine renner 80 SAVING seers cve
234. elAnalog FunctionsIPOP Trigger You should check this box if you are using this component If you do not use the schematic POP trigger device see above you must specify a suitable component in this edit box Enter the full component reference of the device The polarity of the trigger edge You should set this to a value that is larger than the expected period of your circuit s switching cycle During each run SIMPLIS expects to see valid trigger conditions However if there is a fault in the design of the circuit or a fault in the definition of the trigger conditions it is possible that none will be detected The Max period prevents SIMPLIS from carrying on indefinitely in such an event Cycles before launching POP SIMPLIS will run a number of switching cycles in a normal transient analysis before starting the periodic point algorithm This can speed up convergence of POP or in some cases make the difference between POP converging and not converging If you find POP does not converge increasing this value can Chapter 8 SIMPLIS Analysis Modes sometimes help Advanced POP Options Press the Advanced button for more POP options la POP options Convergence E 3 E Defaut Iteration limit 20 a E Defaut srein E S E Defaut E Use snapshot from previous transient analysis E Output POP progress Define transient after failed POP W Enable automatic transient analysis after a failed POP Use defa
235. eleton Configuration File The skeleton configuration file if it exists will be copied to base sxprj if base sxprj does not exist The skeleton configuration file must be called skeleton sxprj and be located in the same directory as the executable file SIMetrix exe windows or SIMetrix Linux Installation Customising It isn t possible to customise the Windows install program However the SIMetrix installer doesn t do much more than simply uncompress files to the chosen location It is therefore possible for you to create your own SIMetrix install process using a fresh install tree as a source image You can then add your own files to this including the skeleton sxprj file described above Colours and Fonts Colours Colours for schematic symbols wires graph curves and graph grids may be customised using the colour dialog box This is opened using the FilelOptionsIColour menu item Select the object whose colour you wish to change then select Edit button to change it The colours you select are stored persistently and will remain in effect for future sessions of SIMetrix Fonts Fonts for various components of SIMetrix may be selected using the font selection dialog box This is opened using the FilelOptions Font menu item Select the item whose font you wish to change the press Edit to select new font Items available are 385 User s Manual 386 Font object name Where font used Associate Mode
236. elled by L1 and R1 while D1 is a freewheel diode S1 is the relay driver and is controlled by the output of U2 This is a simple counter implemented using the following Verilog code 344 Chapter 13 Verilog HDL Simulation module pulse_relay in out input in output out integer count reg out parameter divide_ratio 10000 parameter real duty 0 1 always posedge in begin count count 1 y if count divide_ratio count 0 if count gt divide_ratio 1 duty begin out 1 end else begin out 0 end end initial count 0 endmodule The Verilog files as well as a completed working schematic can be found in Examples Verilog HDL Tutorial Procedure The following assumes that you are already familiar with the basics of entering a schematic and running a simulation Enter Schematic 1 Open a new empty schematic sheet 2 Immediately save the empty sheet to Examples Verilog HDL Tutorial relay driver sxsch In general it is strongly advised to save the schematic sheet before using the automatic Verilog symbol generation scheme that we are about to demonstrate This is to ensure that the file system paths of the schematics and Verilog files are kept correctly synchronised 3 Select menu Verilog Construct Verilog HDL Symbol You should see the file clock v listed If so select it then click Open If you don t see the file make sure you saved the schematic to the correct location
237. els IRF530 if5m3415 RF623 Diode RF530 1R irf5m3710 RF624 Gates RF530F1 if5n3205 RF630 Linear Regulator RF530N if5n3415 RF630 IR NMOS RF530N IR if5n3710 RF630FI NPN RF530NS if5nj3315 RF630S PMOS RF530NS IR if5nj540 RF631 PNP RF530S if 5njz34 RF632 PSU Controllers if 530V if5njz48 RF633 PSU Drivers RF531 if5y1310cm RF640 Varactor Diodes RF532 if5y31n20 RF640 IR Voltage References RF533 if5y3205cm RF640FI Zener Diodes RF540 inf 5y3315cm if640ns RF540 IR inf 5y37100m RF640S RF540FI inf 5y5400m RF640S IR RF540N RF610 RF641 RF540N IR RF610 1R RF642 irf540ns RF610S RF643 RF540S RF611 inf 644s IRFS30 o irf5402 RF612 if6601 eoe eo if540zs_ RF613 if6602 el ie an i RF541 inf 6156 inf 6603 Q1 RF542 RF620 if6604 RF543 RF620 IR if6607 if5801 RF620F1 inf 6608 inf 5802 RF620S inf 6605 Eter E __Bece _ __Senca Hep C Program Files S Metrix620 support Models mosfet b Select the appropriate category on the left then the part number on the right The picture above shows what you would see if selecting an IRF530 from the NMOS category If you are not sure what category the component is in select the All Devices category which you will find at the bottom of the category list If you are looking for a part that you installed as opposed to a part supplied with SIMetrix then you will find it in the All User Models category as well as the All Devices category If installed within the last 30 days y
238. ely identified by their name Chapter 6 Device Library and Parts Management SIMetrix has a built in utility that can automatically rename models with duplicate names The devices are renamed by adding a user specified suffix to the model name The rename utility is not accessible via the menus but must be invoked by typing a command at the command line Proceed as follows 1 First ensure that all the model library files you wish to process are installed as global libraries 2 Make backup copies of your model files This is optional the utility makes backups anyway 3 Type at the command line i e the edit box below the menu bar in the command shell rename_libs 4 A list of currently installed libraries will be displayed Double click on any that you wish to be processed for renaming and supply a suffix The suffix must not contain spaces and should start with a non alphanumeric character such as or Note that only models found to have duplicates will be renamed SIMetrix will not rename unique models If you do not supply a suffix for a library no devices within it will be renamed 5 Press OK The operation can take a long time possibly a few minutes if the library is large On completion the message RENAME COMPLETE See RENAME LOG for details will be displayed in the command shell The RENAME LOG file will contain full details of the rename process This includes details of all models that were renamed Notes
239. emDoubleClickScript ScriptDir 376 Type Text Text Boolean Text Text User interface support Description Default NoSnap Options Schematic behaviour when dialog double clicking If set to Classic a wire is started If set to NoSnap a script defined by SchemDoubleClickScript is called Standard behaviour is to edit a component if mouse is located inside one Default ClassicMode Controls wiring behaviour with schematic move operations Values are ClassicMove GrowWire and Orthogonal See Edit Modes on page 69 for details Options dialog Default false No If set all schematics are opened in read only mode Default on_schem_double _click ne Script that is called when a double click action is detected in the schematic Only active if SchematicEditMode NoSnap Default SXDOCSPATH Options Scripts dialog SXDOCSPATH is My Documents S Metrix on Windows and HOME simetrix on Linux Directory used to search for scripts and symbol files if not found in the current directory Changes to this option do not take effect until next session Chapter 14 Sundry Topics Name Type Description User interface support ScriptExtension Text Default sxscr Options File extension used for dialog scripts ShellCommandProcessor Text String used to launch command processor when command supplied with Shell script command See Shell comman
240. eneeeeeeeeeeeeeeees 172 Local Models 32 0 eiae secesissicieedsgaieserenaaanecusane 172 Library Indexing Mechanism 172 Duplicate Model Names nsec 172 Chapter 7 Analysis Modes Running Simulations c ceceesceeeeeeeeeeseeeeeneeeeeeeenreeaes 175 OTA EPRE LETE ATTAT 175 Starting Pausing and Aborting Analyses 175 Running Analyses in Asynchronous Mode 176 Running an Analysis on a Netlist eee 176 Transient Analysis ceeeseeeeeseeeeeneeeeeeneeeeeneeeeeneeeees 176 Setting up a Transient Analysis c cceeee 176 Restarting a Transient Run 179 Transient Snapshots c ceceeseeseeeeeeeseeseeeeeneeeees 179 Operating Pointes neinni eeian ieee 181 SWeep MOdeS oei ssn ide ded aes 182 Device SWEEP ceeceeeseseeeeeneeeseeeeneeeeeteaeeneetsatenes 182 Temperate iie einna s eudeemens destoraneetes 183 Model Parameter eecceescceeseneeessseeereneeeeeeeeeeaes 183 ParaM te rei secceitscfeatescpdssceastatisdesestarticas este tebe 183 FreQUuency ese an aene aie de eee 185 Monte Carlo wzstechaccieitsih pastathiveiestacelc ET E 185 Setting up a Swept Analysis eceeeeeeeeeeenees 185 DG SWCD EEA TE sachs 186 Setting up a DC SWEED ee eeceeeeeeeteeeteeteeeeeeeteees 186 Exampleit sin teil eel Ra 187 User s Manual Chapter 8 AC SWEEP x titi a e A e a at a Ea 188 Setting up an AC SWEED eeeeeeeeeeeeteteeeneeeteees 188 EX IMpPlO ies EE ET 189
241. eneeeeeneeeesnneeeeneees 329 SumNoise real real real eeeeesseeeeeeeeeeees 329 tan real COMPIeX ce eeeceeeeseeeeeneeeteneeeeseeeeeeneeeeeaes 329 Truncate real real real c e 329 UNITVEC FEAl s pirripita 330 vector real setsit haare a a a aiaa eaa 330 XFromY real real real real 1 a 330 AY real real cc 22casecspeia iedectcr sesseersantieesctisncensadie 330 YFromX real real reall 330 Chapter 12 Monte Carlo Analysis An Examples ci i a cs N N 332 Component Tolerance Specification 334 Setting Device Tolerances 334 Model Tolerances eescceesceeeeseeeeeeneeeeeneeeeeneeeeeas 335 Matching Devices eeccceeseeesseceeeeeeesesereeeeeeeeens 335 Random Distribution 2 0 0 eeeeeseeeeseeeteneeeeenenereaes 336 Running Monte Carlo cecccseeseeseeeeeeeeeeeeenresseeesreeaas 336 OVenieW ae aie ae ed adhe S 336 Setting up a Single Step Monte Carlo Sweep 336 Setting up a Multi Step Monte Carlo Run 337 Running a Monte Carlo Analysis c cceeeeeee 337 Setting the Seed Value cccceceesseeeeseteeeeeeees 337 Analysing Monte Carlo Results eee 338 PlOtS shart cee diel eee eas ai 338 Creating HistOgrams eecceseeeeeeeeeeseeeeeeeneeeees 339 Chapter 13 Verilog HDL Simulation OVGIVIEW nisin heer ee eae eee 341 Documentations a 25 33 rr a e are eine pci altace 341 Supported Verilog Simulators ceeceeeeseeeeeeeeeeeee
242. ept its name and the change will be applied to all selected pins Moving Pins or Pin Names Moving any item in the symbol editor is done the same way as in the schematic Note however that pin names are attached to the pins If you move a pin its name moves with it You can move the name on its own by making sure that only the name is selected and not the pin Defining Pin Order The symbol s pin order is important if you are defining a symbol for use with a sub circuit or primitive simulator device If it is a sub circuit the symbol s pin order must match the order in which the corresponding nodes are defined in the SUBCKT Chapter 4 Schematic Editor statement If the symbol is a primitive device then it must follow the order defined in section Summary of Simulator Devices on page 115 If you are creating a symbol for a hierarchical block you do not need to define the pin order The connection between the symbol and the underlying child schematic is made by name To define the symbol s pin order select menu Property PinlEdit Pin Order Use the up and down buttons to reorder the pins as appropriate Adding XSpice Pin Attributes Some XSPICE devices support vector connections and or variable type connections These are designated in the netlist with the characters and and are explained in the Digital Simulation chapter of the Simulator Reference Manual You can add these to a symbol by prefixing the appro
243. ept that no substitution takes place if the nopinnames switch is specified for the Netlist command MAPPEDPINNAMES lt MAPPEDPINNAMES gt As PINNAMES but with the mapping property applied See MAPPEDNODE above NODENAME lt NODENAME gt This is not replaced by any text but signifies that the item following is a node name The netlist generator must be able to identify any text that is a node so that it can correctly substitute the name when required For example the following is the template definition of the N channel MOSFET with bulk connected to VSS smodel ref lt nodelist gt lt nodename gt vss value If VSS were actually connected to ground the netlist generator would replace all nodes called VSS with 0 meaning ground If the lt nodename gt keyword were not present in the above the netlist generator would not be able to determine that VSS is a node and the substitution would not take place SEP lt SEP gt 101 User s Manual 102 Returns separator character used to separate the device letter and component reference This defaults to but can be changed at the Netlist command line See Netlist command syntax in the Script Reference Manual REF lt REF gt Returns the component reference of the device using the same rules that are used when the template property is not present The rules are if MODEL property is blank OR MODEL is a single character AND first letter of REF property equals MODEL p
244. ept the result wraps at pi pi radians atan real complex Returns the arc tangent of its argument If degrees option is set return value is in degrees otherwise radians cos real complex Return cosine of argument in radians Use cos_deg if the argument is in degrees db real complex Returns 20 log10 mag argument diff real Returns the derivative of the argument with respect to its reference x values If the argument has no reference the function returns the derivative with respect to the argument s index in effect a vector containing the difference between successive values in the argument exp real complex Returns e raised to the power of argument If the argument is greater than 709 016 an overflow error occurs fft real string Vector to be processed String specifying window type Possible values are Hanning default and None Performs a Fast Fourier Transform on supplied vector The number of points used is the next binary power higher than the length of argument 1 Excess points are zero filled Window used may be Hanning default or None Users should note that using this function applied to raw transient analysis data will not produce meaningful results as the values are unevenly spaced If you apply this function to simulation data you must either specify that the simulator outputs at fixed intervals select the Output at interval option in the Choose Analysis dialog box or you must interp
245. er of menus Default is notepad under Windows and gedit under Linux PSpice inifile Set this file location if you wish to use the PSpice Schematics translator See PSpice Schematics Translation on page 110 for more information Scripts Location of script directory This directory is searched for any scripts you run Only change this setting if you are actually moving the script directory Changing this setting has no effect until you restart SIMetrix Start up Current working directory on start up Start up Script Name of script that is automatically run on startup You can place custom menu or key definitions in this file System Symbols Location Directory location where the standard symbols are located Temp Data Location of temporary simulation data files Changing this setting has no effect until you restart SIMetrix Note that this should always be a local directory That is it must not be on a remote network partition User Symbols Location Directory where user symbol libraries are expected to be located Note you can place symbol libraries anywhere This directory is simply a location that some UI functions use as a default File Extensions Defines extensions used for the various files used by SIMetrix Most SIMetrix file types use five letter extensions beginning with sx This is to help prevent clashes with other applications For each setting the supported extensions are separated by a semi colon Th
246. ere are two ways of doing this The quickest is to simply drag the mouse over the region of interest The other method is to manually enter the limits using the Edit Axis Dialog Box To zoom with the mouse proceed as follows 1 2 Make sure that the graph window is selected by clicking in its title bar Place the cursor at the top left of the region of interest i e to the left of the y axis and above the top of the red curve Press the left mouse key and while holding it down drag the mouse to the bottom right of the area you wish to zoom in You should see a rectangle appear as you drag the mouse Release the mouse key You should see something like 25 User s Manual 26 irst attempt gt E 5 2 2 fe 8 2 Q lt 0 50 100 150 200 250 300 350 400 Time nSecs 50nSecs div If you don t get it quite right press the Undo Zoom button to return to the previous view You can also use the left right up and down arrow keys to shift the position of the curves We can probably improve the ringing by adding a small phase lead in the feed back loop This can be done by connecting a small capacitor between the emitter of Q3 and the base of Q2 There isn t room to add this tidily at present so first we will move a few components to make some space Proceed as follows 1 In the schematic window drag the mouse with the left key pressed over the region shown by the dotted lines below
247. erface Configuration In order for the interface to be setup SIMetrix needs to know how to drive the Verilog simulator Also the Verilog simulator needs to know about vsxd vpi The interface is configured by the VerilogHDL ini file which is located in the support folder under windows or in usr local simetrix_nn share under Linux VerilogHDL ini uses the standard inifile format Each supported simulator is defined in a section within VerilgHDL ini and the section must at a minimum define the following keys Name Script and Path Name defines a display name for the simulator that will be meaningful to the user Script defines a script name that is used to launch the Verilog simulator More on the launch script below Path is passed to the launch script and would usually be the path where the main binary executable for the Verilog simulator is located Launch Script The launch script is a SIMetrix script that is called by SIMetrix It is responsible for starting the Verilog process usually via the Shell function The launch script knows about the command line syntax for the Verilog simulator For more details about the launch script see the script used to launch the GPL cver simulator Verilog Simulation Preparation SIMetrix netlists can instantiate any number of verilog designs both multiple instances of the same Verilog module and multiple module designs In order for the Verilog simulator to be
248. eric digital devices are provided on the PlacelDigital Generic menu Each will automatically create a symbol using a basic spec provided by your entries to a dialog box Functions provided are counter shift register AND OR NAND and NOR gates and bus register Functional Blocks Overview The simulator supports a number of devices that are arbitrary in nature and which are used to define a device in terms of its function or behaviour Functional blocks have a number of uses Here are two examples 1 System level simulation You are investigating the viability or characteristics of a complete system before actually considering its implementation detail Your system may consist of a number of interconnected blocks each with an easily defined function 2 Device model implementation Functional models can be used to actually create device models Suppose you wish to use an op amp for which no model is available The only characteristic that affects the performance of your circuit is 145 User s Manual its gain bandwidth product So instead of creating a detailed model you simply use a differential voltage amplifier with the appropriate GBW SIMetrix provides functional modelling at both the schematic and simulator levels The schematic provides a convenient user interface to the functional devices provided by the simulator The simulator provides three devices that can be defined in a completely arbitrary manner These are defined
249. ertain times but for performance reasons does not netlist the whole hierarchy You can use the menu Edit Refresh Hierarchical Highlights to resolve this 79 User s Manual problem This will netlist the complete hierarchy and rebuild the highlights from scratch Copying a Hierarchy A complete hierarchy may be copied for archival purposes subject to certain conditions as follows 1 The hierarchy must use relative paths throughout 2 All child components must be either in the same directory as the root or in a directory that is a direct descendant of the root If these conditions are met then the hierarchy may be copied using schematic menu File Copy Hierarchy Before any file copying is started checks that the above conditions are met is made first A check will also be made for any existing target files to ensure that no existing file will be overwritten If all checks are successful you will be presented with a list of all the files that will be copied before the copying operation is started Printing Printing a Single Schematic Sheet 1 Select menu File Print 2 If there is a graph window currently open See Graphs Probes and Data Analysis on page 221 you can choose to plot the schematic alongside the graph on the same sheet Select your choice in the Layout section 3 In the Schematic box select an appropriate scale Fit area will fit the schematic to a particular area relative to the size of paper If
250. es on page 72 If current mode is selected it is the name of a voltage source through which the output current is measured The simulation will calculate the gain for every circuit source to this current 195 User s Manual Reference node Optional and only available in voltage mode Output voltage is referred to this node This is assumed to be ground if it is omitted Source name Optional Input impedance to this source will be calculated if specified Monte Carlo and Multi step Analysis See page 200 See Also TF in Simulator Reference Manual Plotting Transfer Function Analysis Results See Plotting Transfer Function Analysis Results on page 231 Example Perform transfer function frequency sweep on the following circuit 5V Vi 10m AC 1 0 O ea 7 v2 OsuB Transfer function frequency sweep The results 196 Chapter 7 Analysis Modes Series ode gain Gain from V2 to output Common mode gai Gain from V1 to Output 100k 1M 10M 100M 1G Frequency Hertz All of the above waveforms were created with a single analysis Sensitivity This control instructs the simulator to perform a DC sensitivity analysis In this analysis mode a DC operating point is first calculated then the linearised sensitivity of the specified circuit voltage or current to every model and device parameter is evaluated The results are output to a file SENS TXT b
251. es will be displayed Notes To enter multiple expressions separate each with a comma The display of arrays with a very large number of elements gt 500 can take a long time For large arrays it is recommended that the file switch is used to output the results to a file The file can then be examined with a text editor or spreadsheet program The results will be tabulated if all vectors are compatible that is have the same x values If the any vectors listed are not compatible each vector s data will be listed separately The precision of numeric values can be controlled using the Precision option setting Use the command Set precision value This sets the precision in terms of the column width Unset UnSet temp option_name temp If specified the option setting will be deleted temporarily and will be restored to its original value when control returns to the Chapter 11 Command and Function Reference command line i e when all scripts have completed option_name Name of option This would usually be defined with a value using Set See Options on page 357 for a complete list Deletes specified option See Options on page 357 for a full explanation Note that most Option values are internal This means that they always have a value If such an option is UnSet it will be restored to its default value and not deleted See Options on page 357 for more details If Unset is called
252. ete on the left hand side then press Remove To subsequently restore a deleted item use Add Item see below To Move a Menu Item or Sub menu Select the item then use the up and down arrows key to move as required If you wish to move a menu item to a different sub menu you should remove it as described above then add it again using Add Item see below To Add a New Menu Item You can add a previously removed menu item to a new location or you can create a completely new menu item In both cases select the location within a sub menu and press Add Item To add a previously removed menu select Add Existing and choose an item in the left hand pane Chapter 10 The Command Shell This pane will be empty if you have not previously removed any menu items This could be in a previous session as deleted items are always remembered To add a new item press Add New then enter the required values For Name enter the name of the menu as you would like to see it in the menu itself Use the amp character to denote underlined letters used to denote Alt key short cuts E g amp My Menu will be displayed My Menu and will be activated with Alt M For Command String you must enter a valid SIMetrix command Typically this would call a user defined script but you may also enter primitive commands or a list of primitive commands separated by semi colons See the Script Reference Manual for full details To add a separator
253. eters Through a Hierarchy To pass parameters through a hierarchy assign a PARAMS property then give it a value to assign each parameter you wish to pass e g PARAM1 10 PARAM2 57 See supplied example in folder Examples Hierarchy Passing Parameters This feature works in both SIMetrix and SIMPLIS runs Note however that this feature did not work for SIMPLIS in version 5 6 and earlier Adding Parameters to a Symbol The PARAMS property is most easily added in the symbol editor when the symbol for the hieararchical block is created This is the procedure 1 Open the symbol in the symbol editor If you are editing a hierarchical symbol that has already been created and placed on a schematic select the symbol then menu HierarchylOpen Create Symbol for Schematic In the symbol editor select menu Property Pin Add Property This will open the Add Property dialog box In the Name box enter PARAMS In the Value box enter the parameter names and their default values For example PARAM1 10 PARAM2 57 You can leave the remaining settings at their default values or edit as desired Ok Add Property dialog box Select menu FilelSave then click Ok to close Close symbol editor window if desired The above procedure will add the PARAMS property to all new instances of the symbol It will not add the property to any existing instances already placed on a schematic If you have already placed instances of the symbol you can update it
254. etrix has the ability to display any number of cursors not just the standard two To Add an Additional Cursor 1 Select menu Add Additional Cursor 2 Enter a suitable label for the cursor This is displayed at the bottom of the graph and to avoid clutter we recommend that you use a short label such as a single letter 3 Select to which other cursor you wish the new cursor to be referenced for both horizontal and vertical dimensions Select none if you do not wish it to be referenced to any currently displayed cursor Note that you may reference further additional cursors to this one if desired 4 Press Ok The new cursor will be initially displayed at the start of the x axis and attached to the first curve on the sheet You may subsequently move it as desired To Remove Additional Cursors 1 Select Cursors Remove Additional Cursors 2 Select the cursor or cursors to be removed These are identified by their labels Cursor Readout There are a number of options as to how the cursors absolute and relative positions are displayed Initially all values are displayed as dimensions on the graph This can be altered in a number of ways You can opt to have just the absolute or just relative readings displayed The actual format of the graph readout can be customised E g extra text can be added perhaps something like Delay xxxnS where xxx is the relative reading The values can optionally be displayed i
255. ex and end index define the wires within the bus that you wish to connect to Suppose you were connecting to a data bus called DATA and it was 16 bits 69 User s Manual 70 wide If you wish to make a connection to the 4 bits from DATA8 to DATA11 you would enter 8 and 11 for the start and end index respectively The bus ripper doesn t care about the size of the bus to which it is connecting 3 Choose an appropriate style This only affects the appearance of the symbol not its functionality 4 Press OK then place the symbol on your schematic To Draw Busses There is no special method of drawing busses Simply wire up bus rippers as you would any other component As soon as you connect to the bus pin of a bus ripper the colour and thickness of the wire will automatically change to signify that it is a bus To Increase Reduce the Connections to a Bus If you wish to add connections to or delete connections from a bus ripper select the ripper device and press F7 or popup menu Edit Part The same dialog as above will be displayed Adjust the start and end indexes appropriately then close the box Connecting Busses in a Hierarchy See Connecting Busses in a Hierarchy on page 75 Copying to the Clipboard To copy schematics to the clipboard select the entire schematic then choose menu EditlCopy If you wish the schematic to be copied in black white select EditlCopy Monochromatic It is recommended that you zoom the sche
256. explanation in the Overview above If this is necessary you will be prompted for the information required See Placing New Model on Schematic below Full Model Installation Procedure The following is the full procedure for installing models including association if required 163 User s Manual 164 Installing Electrical Model 1 Open a suitable file manager program such as windows explorer in Windows systems or equivalent in Linux systems Locate the folder where your model files are located Select the items you wish to install You can also install a single file multiple files an entire folder or multiple folders You only thing you can t do is install files and folders at the same time Make sure that the SIMetrix command shell is visible If it is obscured you can bring it to the surface by pressing the spacebar with a schematic or graph selected Pick up the items selected in 2 above and drop them into the message window of the command shell If you installed individual files you will see a message box asking you to confirm that you wish to continue Just click OK The model files are now installed If you drop folders a search will be made in those folders for SPICE models The Add Remove Models dialog will then be displayed as shown below r J Select Libraries E Currently Selected Libraries CAP Metrix620 support Models digital rogram Files Available Librar
257. f interest then randomly probe to investigate the detailed behaviour of your circuit Chapter 9 Graphs Probes and Data Analysis Note that you can add fixed probes after a run has started but the run must be paused first There are currently 9 types of fixed probe to suit a range of applications The random probing method allows you to plot anything you like including device power FFTs arbitrary expressions of simulation results and X Y plots such as Nyquist diagrams It is possible to set up fixed probes to plot arbitrary expressions of signals but this requires manually entering the underlying simulator command the GRAPH control There is no direct schematic support for this For more info on the GRAPH control see the Command Reference Chapter of the Simulator Reference Manual Fixed Probes There are 9 types of fixed probe as described in the following table Probe Type Description To Place Voltage Single ended voltage Hint If Menu Probe Place Fixed you place the probe Voltage Probe immediately on an existing schematic wire it will Hot key B automatically be givena meaningful name related to what it is connected to Current Device pin current A single Menu Probe Place Fixed terminal device to place over Current Probe a device pin Hot key U Inline current In line current This is atwo Menu Probe Place Inline terminal device that probes Current Probe the current flowing through it Differential
258. fast 5 As a further exercise you may like to see what happens when this node is connected to an analog component Try connecting a 1 pF capacitor to ground and run the simulation You will find that the simulation runs maybe 100 times slower This is because analog time steps is now being performed for this high frequency signal With just the 10Hz output to deal with the analog simulator needed to perform only around 200 timepoints Now it has to work at 100KHz it needs 1 million or so 348 Chapter 13 Verilog HDL Simulation Multi step Run As a final exercise we will show how it is possible to perform multi step runs while varying a parameter sent to a Verilog device We will run a 3 step simulation while varying the DUTY parameter of the pulse_relay device Proceed as follows 1 2 Double click U2 Set the duty parameter to duty Open the choose analysis dialog box In the Transient sheet select Enable multi step then click Define In Sweep mode select Parameter Set Start value and Stop value to 100m and 500m respectively Set Number of steps to 3 In Parameters set Parameter name to duty Ok dialog boxes If you carried out step 5 in the above section Internal Verilog Nodes remember to remove the capacitor and restore the connection between U1 and U2 to an internal Verilog node Run simulation then plot relay drive as before You should see three curves Verilog Simulator Interface In this sect
259. fault SIMetrix outputs the data in a form that is the same as the standard unmodified SPICE3 program This can be modified using the option setting ExportRawFormat Use the Set command to set this value See Set on page 315 for details Set this value to spice3 spectre or other Exporting Data To export data use the Show command page 315 with the file switch E g Show file data txt vout rl_p qlic will output to data txt the vectors vout rl_p and ql c The values will be output in a form compatible OpenGroup text Vector Names In the above example the vector names are vout rl_p and ql c If you simulate a schematic the names used for voltage signals are the same as the node names in the netlist which in turn are assigned by the schematic s netlist generator To find out what these names are move the mouse cursor over the node of interest on the schematic You should see the node name and therefore the vector name in the status box in the form NET To find the current name place the mouse cursor on the device pin of interest and press control P 297 User s Manual 298 Launching Other Applications Data import and export makes it possible to process simulation data using other applications SIMetrix has a facility to launch other programs using the Shell command You could therefore write a script to export data process it with your own program then read the processed data back in
260. fcursor x1 graph refcursor y1 graph grouptitle graph sourcegroup curvet label curve2 label curve shortlabel curve2 shortlabel curvet xunit curve2 xunit curvet yunit curve2 yunit date time Aversion Curve s x axis label Curve s y axis label Any measurements assigned to the curve x position of main cursor y position of main cursor x position of ref cursor y position of ref cursor Title of initial data group This is actually the netlist title first line and for schematic simulations will be the full path of the schematic Data group name that was current when first curve added to graph E g tran1 dc5 etc Label for curve attached to crosshair 1 Label for curve attached to crosshair 2 Curve s label without the groupname suffix that is sometimes displayed Curve2 s label without the groupname suffix that is sometimes displayed Curvet s x axis units Curve2 s x axis units Curvet s y axis units Curve2 s y axis units Date when object created Time when object created Product name and version Curve marker Curve marker Curve marker Anything Anything Anything Anything Anything Anything Dimension Dimension Dimension Dimension Dimension Dimension Dimension Dimension Textbox free text caption legend box Textbox free text caption legend box Textbox free text caption legend box Chapter 9 Graphs Probes a
261. ference out of range an empty result is returned The sampled input vector is interpolated to produce the final result Interpolation order is specified by argument 3 331 User s Manual Chapter 12 Monte Carlo Analysis Overview Monte Carlo analysis is a procedure to assess manufacturing yields by repeating simulation runs with varying applied random variations to component parameters The technique is very powerful and usually gives a more realistic result than worst case analysis which varies component values to their extremes in a manner which produces the worst possible result The implementation of Monte Carlo analysis in SIMetrix has been designed to be quick to set up for simple cases while still providing the required flexibility for more advanced requirements as might be required for integrated circuit design In this chapter we cover the aspects of setting up a Monte Carlo analysis from the front end This includes setting device tolerances in the schematic setting up and running a Monte Carlo simulation and analysing the results This chapter covers Monte Carlo analysis for SIMetrix SPICE simulations Monte Carlo analysis is also available for SIMPLIS simulations See Multi step and Monte Carlo Analyses on page 213 Setting model tolerances is not covered here but in the Monte Carlo Analysis chapter in the Simulator Reference Manual An Example 332 Consider the following active filter circuit 6 2n
262. fied by their y axis title Use the up and down arrow buttons to arrange them in the order required then press Ok Note that the main axis the one at the bottom cannot be moved To change the digital axis order 1 2 Select menu AxeslReorder Digital Axes Rearrange entries in list as described above for analog grids Plotting the Results from a Previous Simulation 1 2 Select the menu item SimulatorlChange Data Group Select the name of the previous run or group that you require The current group will be highlighted Note that the AC analysis mode generates two groups One for the AC results and the other for the dc operating point results Transient analysis will do the same if the start time is non zero Plot the result you require in the normal way A word of warning If the schematic has undergone any modifications other than component value changes since the old simulation was completed some of the netnames may be different and the result plotted may not be of what you were expecting 251 User s Manual 252 Note By default only the three most recent groups are kept This can be changed using the GroupPersistence option using Set command see Set on page 315 or a particular group can be kept permanently using the SimulatorlKeep Current Data Group menu item Although only three groups are held at a time the data is actually stored on a disc file which will not necessarily have been delete
263. figuration Options on page 383 CachePathSymbols Boolean Default false If true SlIMetrix will cache unsupported symbolic paths 365 User s Manual Name CancelOnFocusLost CatalogExtension CommandShellMainButtons CommandShellMainNo SchemButtons ComponentButtons ComponentExtension CursorDisplay 366 Type Description User interface support Boolean Default True on No Text Text Text Text Text Text Windows False on Linux When true interactive actions are cancelled when the window focus is lost This can cause problems if the environment is set up with Point to give focus as moving the mouse outside the active window then cancels the user s action Point to give focus is available on Linux systems Default cat File extension used for catalog files See Chapter 7 Script Reference Manual Creating and Modifying Toolbars for details as CommandShellMainButtons above as CommandShellMainButtons above Default sxcmp File extension for schematic component files Options dialog Default Graph Controls Options initial graph cursor readout dialog display Graph Display on graph only StatusBar Display on status bar only Both Display on both graph and status bar Chapter 14 Sundry Topics Name Type Description User interface support CurvePrintWidth Numeric Default 0 5mm Options Width of printed graph dialog curves in
264. file extension SXCMP In earlier versions the symbol or block had to be stored in the symbol library while the schematic was stored as a separate file This method is still supported but we recommend using the component method for all new designs All the methods for creating hierarchical schematics described in this section use components Top Down Method Creating Component Symbol Select schematic menu HierarchylCreate New Symbol This will open the graphical symbol editor See page 82 for details Note that the symbol you create must be given a Ref property typically with the initial value U and a Model property which must have the value X Placing Symbol If the schematic containing the block has never been saved untitled in caption bar you must save it now This is so that the schematic has a title This step is only necessary if the schematic has never been saved before Select either Hierarchy Place Component Full Path or HierarchylPlace Component Relative Path The first references the component file using a full file system path name while the second uses a path relative to the parent schematic See Placing Full vs Relative Path on page 74 for more details Select the SXCMP file you used to save the symbol in the above paragraph Note that you will see the warning message Component module ports in underlying schematic do not match symbol pins displayed in the command shell This w
265. file or netlist file There are 8 fonts assigned for use on schematics This means that you can have up to eight different fonts on a schematic The actual definition of that font is defined in the Font dialog and stored with your user settings and is not stored in the schematic Only Chapter 14 Sundry Topics the name as in the list above is stored with the schematic property This means that if you give a schematic file to a colleague it may display differently on his machine depending on how the font options are set up So for this reason it is best to keep to the allocated purpose for each font Caption fonts should be large and possibly bold free text should be smaller etc etc Using a Black Background SIMetrix uses a white background for all its windows as is convention with GUI applications But it is possible to change to a black background if this is preferred To do this select menu File Options Background Colour This will change the schematic symbol and graph windows to use the background colour selected Note that in order to use a black background the various graphical elements e g fonts and grids that need to contrast with the background will also need to have their colour changed The above menu will deal with this automatically but be aware that these changes will override any previous colour changes that you may have made Startup Script The startup script is executed automatically each time SIMetrix is
266. fine Measurement GUI select menu Measure More Functions You will see the following dialog box Chapter 9 Graphs Probes and Data Analysis J Define Measurement Pre defined Measurement Pre process Choose measurement E Cursor span Custom F Integral cycles Mean E AC coupled Maximum Minimum Peak To Peak Rise Time 10 90 manual Rise Time 10 90 auto Rise Time custom auto Fall Time 10 90 manual Fall Time 10 90 auto Fall Time custom auto Duty cycle Overshoot relative 3 1 5 Measures RMS Choose measurement Lists all available measurement functions If cursors are not switched on some of the functions will be greyed out These are functions that require you to identify parts of the waveform to be measured For example the manual rise and fall time measurements require you to mark points before and after the rising or falling edge of interest When you click on one of the measurements some notes will appear at the bottom explaining the measurement and how to use it Pre process Listed in the pre process box are three operations that can optionally be performed on the waveform before the measurement function is applied These are Cursor span Truncates the waveform data to the span defined by the current positions of the cursors In other words ther measurement is performed on the range defined by the cursor positions Integral cycles Truncates the waveform da
267. form from the Monte Carlo run Plot a result as normal then switch on cursors Place the cursor on the curve of interest then select menu Cursors Show Curve Info The run number will be displayed in the command shell For more information about graph cursors see Graph Cursors on page 254 3 Locate the file simplis_mclog log file you should find this in the same folder as the top level schematic in your design Open this file in a text editor and note the seed value corresponding to the run number identified in step 2 Using the Seed Value You can use the seed value to repeat the run associated with it Follow this procedure 1 Select menu Simulator Setup Multi step In the Monte Carlo Seed group check the Enable box and enter the seed value obtained from step 3 in the above section Set the Number of steps to 1 2 Run the simulation as normal Finding Component Values Used The component values used for a particular step can be found by studying the deck file that is created for every SIMPLIS run To do this follow the procedure for finding and using the seed value as described above Then after the single run is complete locate the file with the deck extension This will be located in the SIMPLIS_DATA folder and will have a name the same as the top level schematic but with the extension deck So if your schematic is called DC DC Converter sxsch the deck file will be called DC DC Converter deck and will be located in the SIMP
268. g bias point 278 editing 63 adding free text 66 copying across schematics 65 deleting wires 64 disconnecting wires 44 64 duplicating items 65 labelling nets 72 move single component 64 moving labels 65 67 Index 399 User s Manual 400 placing components 63 rotate mirror or flip a component 43 64 undo 66 undo setting level 357 wiring 64 getting started 42 grid hiding 358 hierarchical 72 ascending 74 bottom up method 74 connecting busses 75 creating blocks 73 descending 74 global nets 76 global pins 76 navigating 74 passing parameters 78 probing 228 243 running simulation 58 top down method 73 importing models 171 modes 62 net names displaying 72 user defined 72 preferences 71 component placement options 72 toolbar 71 properties 94 decscript 96 editing in schematic 97 handle 96 incscript 96 lot 96 mapping 96 match 96 model 95 156 netname 96 params 96 ref 95 156 restoring 97 schematic_path 96 scterm 96 simulator 96 Index template 96 tol 96 value 95 156 valuescript 96 selecting 63 components only 65 multiple 65 wires only 65 symbols adding properties 87 changing search order 109 copying 109 creating 84 creating from script 93 defining pins 85 drawing arcs 84 drawing segments 84 editing 84 editing properties 92 graphical editor 83 how they are stored 115 installing 109 library manager 107 pin order 86 properties 94 renaming 109 uninstalling 109 Xspice pin attributes 87 to
269. green curve you can simply pick up the cursor at its intersection with the mouse and drag it to the other curve Chapter 2 Quick Start 5 We now have two curves on the graph so we must select which one with which we wish to make the measurement To do this check the box as shown File Edit Cursors Annotate Curves Axes View Measure Plot B QQA s KA HHE E BRT TR Z m 7 Power Q1 Dm 7 Power Q1 tran3 6 As before press F3 then select Mean with the cursor span pre process option The new peak power cycle will now be in the 11 12W region much more than before Tutorial 3 Installing Third Party Models In this tutorial we will install a device model library For this exercise we have supplied a model library file TUTORIAL3 MOD with just two devices These are SXN1001 an NPN bipolar transistor SXOA1000 an opamp Both are totally fictitious You will find this file in the tutorial folder i e Examples Tutorials Tutorial3 mod There are two aspects to installing a model SIMetrix needs to know where within your file system the model is located If the model is to be listed in the parts browser system then SIMetrix also needs to know what symbol to use for it in the schematic and what category it comes under This is how you do it 1 Open windows explorer or click on My Computer or open other file manager of your choice 2 Locate TUTORIAL3 MOD in EXAMPLES Tutorials see Examples and Tutoria
270. gt gt Repeats body for each pin on the symbol var is a variable that will be assigned with the pin number being processed and may be used inside an expression body may also use keywords lt node gt and lt pin gt to access connected nodes and pin names respectively NUMPINS lt NUMPINS gt Returns the number of pins on the symbol owning the TEMPLATE property Further Information To put a new line in the netlist entry you can use a Literal new lines are also accepted To put a literal lt gt or character in the text use two of them So lt lt will become E Template Scripts It is also possible to write a script to compile the line generated by the netlist generator Such scripts are called Template Scripts With this approach you enjoy the full power of the scripting language and very complex devices can be created in this manner For full details of this approach please refer to the Script Reference Manual Symbol Library Manager The symbol manager is a comprehensive system for managing symbols and the libraries that store them To open the symbol library manager select command shell menu FilelSymbol EditorlSymbol Manager The dialog shown below will be displayed 107 User s Manual be one Library Manager Symbols analog sxsib a 4 Symbols digital sxsib B BUTs psu sxsib a BJT Load Switch a connection sxsli Dual Complimentary miscellaneous sxsib
271. hich nodes are to be connected externally This is done using the same Module Port symbol used for hierarchical schematic entry see Hierarchical Schematic Entry on page 72 The procedure for defining a subcircuit is as follows 1 Draw circuit using schematic editor including module port symbols to identify external connections 2 Create netlist for circuit To describe the procedure we will use an example Stage 1 Draw Schematic This is circuit of a simple op amp In fact it is the circuit of our fictitious SXOA1000 op amp used in Tutorial 3 See page 37 a a lt A v Q6 o5 PI ai Nt 100 vr rr our T Ri 1K als R A a a a R3 tt lt G Zz The five terminal symbols e g VSN 154 Chapter 5 Components are the connections to the outside world This is a module port symbol which can be found in the schematic menu HierarchylPlace Module Port Important do not use the normal Terminal symbol It is recommended that any model definitions are included in the subcircuit definition This makes the subcircuit self contained If you have referenced models in the device library you can import them into the schematic automatically using the schematic menu SimulatorlImport Models They will be placed in the simulator command window which can be opened by pressing F11 Alternatively you can enter them in th
272. ial condition file This contains a sequence of SIMPLIS netlist commands that initialises a circuit to the state achieved at the end of the run This allows a new run to continue from where a previous run completed The initial condition file can be applied by including it in the netlist for a new run and in some instances this may be the most convenient method However it is also possible to annotate the schematic with the initial condition information This has some advantages 1 The initial conditions back annotated to top level capacitors and inductors will also be recognised in SIMetrix simulation mode 2 Back annotated initial conditions are attached to schematic instances and will be faithfully reproduced if for example a schematic block is copied and pasted to another schematic Please read all of the sections below on back annotation and ensure you correctly understand all the issues involved Chapter 8 SIMPLIS Analysis Modes How to Back annotate a Schematic Simply select menu SimulatorlInitial Conditions Back annotate You will notice a second or two of activity in the schematic and then the operation is complete You should note that SIMetrix SIMPLIS does not distinguish between initial conditions that are back annotated and initial conditions that are applied manually After running the back annotation algorithm you will not be able to restore the initial condition value to those set before You can however use Undo in
273. ies Select the items you wish to install in the lower box and transfer them to the upper box by pressing the Add button You can also change the order of the items in the upper box This affects the search order when a simulation is run Press Ok You will see a message displayed in the command shell Making Device Catalog Chapter 6 Device Library and Parts Management This may take some time please wait When finished the message Completed will be displayed The electrical model or models are now installed Placing New Model on Schematic l You can now place models installed using the parts browser Select schematic menu Place From Model Library You will see a dialog box similar to that shown on page 119 On the left hand side select category Recently Added Models or if the models were installed more than 30 days ago select All User Models You should see the models you have installed listed on the right hand side Select the device you wish to place the press Place At this point one of two things will happen Either A schematic symbol will appear possibly after a short delay for you to place on the schematic sheet If so no further action is needed after placing the symbol OR If SIMetrix is unable to identify a suitable schematic symbol for the model the associate models and symbols dialog box will open See next step The following dialog box will be displayed 165
274. ill be disabled unless graph cursors are enabled Templates Both the graph label and Format template may be entered using a template containing special variables and expressions The following is available Pyn Where n is a number from 1 to 5 y value returned by expression The value returned by the expression may be a vector with up to 5 elements y1 returns element 1 y2 returns element 2 etc oxn Where n is a number from 1 to 5 x value returned by expression The value returned by the expression may be a vector with up to 5 elements x1 returns the x value of element 1 x2 returns the x value of element 2 etc The x values are the values used for the x axis You should be aware that not all functions return x data Puyn The units of the y values Jouxn The units of the x values o Literal character expression expression will be evaluated and substituted expression may contain any valid and meaningful script function For full details see the Script Reference Manual Repeating the Same Measurement The menu Measure Repeat Last Measurement will repeat the most recent measurement performed Applying Measurements to Fixed Probes Measurements may be applied to fixed probes so that the measurement is performed automatically when the simulation is complete To apply a measurement to a probe proceeds as follows 1 Select the probe then right click menu Edit Add Measurements 2 Chapter 9 Graphs P
275. ill display the result of the expression along with its units if any SSee Templates on page 264 for details Save definition to pre defined measurements Short description Full description If checked the measurement definition will be saved to the list shown in pre defined measurements You can optionally enter some further details under Save definition Note that the definition will not appear in the pre defined list until the dialog is closed an reopened Further management of custom measurement definitions can be made using the Measurement Definitions Manager See below This is what will be displayed in the list box under Choose measurment in the Pre defined Measurement tab This is what will be displayed below the list box when the item is selected Measurement Definitions Manager Select menu Measure Manage Measurement Definitions This will open the Measurement Definitions Manager dialog box shown below Chapter 9 Graphs Probes and Data Analysis J Manage Measurement Definitio Co mE Select measurement Measurement definition Label as displayed on graph RMS M s ae Ee RMS data Maximum Expression Enter an expression that Minimum retums the measurement value Peak To Peak Use data to access the curve s data Rise Time 10 90 manual Eg to get the mean squared use Rise Time 10 90 auto Mean 1 data data Rise Time custom auto Fall Time 10 90 manual X Format template
276. imulator Commands on page 57 157 User s Manual 158 Hard Initial conditions are implemented using a voltage source with the DCOP parameter specified This feature is proprietary to SIMetrix and is not compatible with other SPICE simulators Refer to the Simulator Reference Manual for more information on voltage sources and the DCOP parameter Nodesets Nodesets are used to help convergence and also to coerce a particular state for circuits that have more than one possible DC solution More information about nodesets is given in the Simulator Reference Manual To Place a Nodeset 1 Select menu PlacelConnectors Nodeset 2 Place device at the desired location then select and press F7 Enter a suitable voltage Keeps Keeps form part of a system to limit the amount of data that is output during a simulation For some designs the data output can be too great to fit in the available disk space and in these situation the data output needs to be restricted For non hierachical designs the default is for all voltages and currents at the top level i e not in a sub circuit to be output For hierarchical designs data for all signals for the whole circuit are output To restrict the output you can use the KEEP control in the F11 window see Manual Entry of Simulator Commands on page 57 to restrict what data is output E g KEEP noi top will result in only top level voltages and digital signals being output KEEP nov
277. in any object including free text text boxes and captions Captions are identical to free text they just have a different default position and font The numeric functions above will usually result in a display with more significant digits than desirable To format the result with less accuracy use the FormatNumber function For example FormatNumber RMS1 cv curve 5 Will display the result to 5 digits Copying to the Clipboard Overview SIMetrix offers facilities to copy both graph data and the graph s graphical image to the system clipboard This provides the ability to export simulation results to other applications The data for example may be exported to a spreadsheet application for custom processing while the graphical image may be exported to a word processor for the preparation of documents 275 User s Manual 276 SIMetrix may also import data in a tabulated ASCII format This feature may be used to display data from a spreadsheet allowing for example a comparison between measured and simulated data As well as the system clipboard SIMetrix also uses an internal clipboard to which graph curves may be copied This provides an efficient method of moving or copying curves to a new graph sheet Copy Data to the Clipboard 1 Select the graphs you wish to export 2 Select the menu EditlCopy ASCII Data The data will be copied in a tabulated ASCII format The first line will contain the names of
278. in one See diagram in section Graph Layout Multiple Y Axis Graphs on page 246 If the signal is digital a digital axis see below will be used for this probe Use Separate Y axis Will always use its own separate y axis If you specify this you can optionally supply an axis 225 User s Manual 226 Graph Analyses Display order Colour name The value of the axis name is arbitrary and is used to identify the axis so that multiple fixed probes can specify the same one This name is not used as a label for display purposes but simply as a means of identification Axes can be labelled using the Axis Labels sheet See below Use Separate Grid Similar to above but uses a new grid that is stacked on top of main grid See diagram in section Graph Layout Multiple Y Axis Graphs on page 246 Digital Use a digital axis Digital axes are placed at the top of the window and are stacked Each one may only take a single curve As their name suggests they are intended for digital traces but can be used for analog signals if required Check the Use Separate Graph box if you wish a new graph sheet to be used for the probe You may also supply a graph name This works in the same way as axis name see above It is not a label but a means of identification Any other probes using the same graph name will have their curves directed to the same graph sheet Specifies for which analyses the probe is enabled Note other
279. ing and overshoot For some wave shapes the pulse peaks are not well enough defined to give a reliable answer In these cases the measurement will fail and an error will be reported Distortion This calculates residue after the fundamental has been removed using an FFT based method This algorithm needs a reasonable number of cycles to obtain an accurate result The frequency of the fundamental is displayed in the message window Note that most frequency components between OHz and just before the second harmonic are excluded The precision of the method can be tested by performing the measurement on a test circuit such as Chapter 9 Graphs Probes and Data Analysis v2 5 Sine O 1m 2k 0 0 vi 5 Sine 01 1k00 The signal on the pos side of V2 has 0 1 distortion Use V1 as your main test source assuming you are testing an amplifier then after the simulation is complete check that the distortion measurement of V2 is 0 1 If it is inaccurate you will need either to increase the number of measurement cycles or reduce the maximum time step or both You can adjust the amplitude of V2 appropriately if the required resolution is greater or less than 0 1 Note that in general accuracies of better than around 1 will require tightening of the simulation tolerance parameters In most cases just reducing RELTOL relative tolerance is sufficient This can be done from the Options tab of the Choose Analysis Dialog SimulatorlChoose Analysis
280. ing ideal inductors in series with one or more windings In some instances it may be necessary to add coupled inductors in series This is explained in more detail in Coupling Factor on page 133 5 Specify the core characteristics in the Define Core section A number of standard core sets are pre programmed and can be selected from the Select Core Type list at the top If the part you wish to use is not in the list or if you wish to use a variant with a say different air gap you can manually enter the characteristics by clicking on the Manual Entry check box The values you need to enter are Effective Area Effective Length Relative Permeability Core Material Model Details The models for saturable components can be found in the file cores lb Most of the models are based on the Jiles Atherton magnetic model which includes hysteresis effects The MPP models use a simpler model which does not include hysteresis These 131 User s Manual 132 models only define a single inductor To derive a transformer model the user interface generates a subcircuit model that constructs a non magnetic transformer using controlled sources The inductive element is added to the core which then gives the model its inductive characteristics The model does not currently handle other core characteristics such as eddy current losses nor does it handle winding artefacts such as resistive losses skin effect inter winding capacitance or
281. ins the centre of each bin with a straight line to display a continuous curve Controls where cursor values are displayed On graph Values are displayed on the graph itself Status bar Values are displayed in status bar boxes at the bottom of the graph window Both Displayed in both locations as described above Simulation data is stored in temporary data files as explained above The data is not read into system memory until it is needed say to plot a graph However the location in the file of the various vectors is always in memory so that the data can be extracted from the file as rapidly as possible It is this latter location data that is destroyed when a simulation run gets out of date The file containing the data gets deleted at a time set by the above options not necessarily when the data is no longer Chapter 14 Sundry Topics needed As long as the file exists the data can be recovered by calling FilelDatalLoad or FilelDatalLoad Temporary Data which re builds the location data Model Library Library Diagnostics Determines whether messages are displayed when models are found in the library Action on unknown model parameter Shell Scripts Script Options Keys disable File Locations Specifies action to be taken when an unknown model parameter is encountered There are three options Abort simulation an error will be raised and the simulation will be aborted Issue warning a warning message will
282. interval option in the Choose Analysis dialog box or you must interpolate the results using the Interp function see page 324 Example Suppose a vector VOUT exist in the current group simulation results The following will plot VOUT with a 4 sample rolling average applied Plot FIR vout 0 25 0 25 0 25 0 25 Alternatively the following does the same Plot FIR vout 0 25 unitvec 4 Floor real Returns the argument truncated to the next lowest integer Examples Floor 3 45 Floor 7 89 Floor 3 45 4 3 7 321 User s Manual 322 GroupDelay real complex Returns the group delay of the argument Group delay is defined as d phase y 1 dx 2 4 where y is the supplied vector and x is its reference The GroupDelay function expects the result of AC analysis where y is a voltage or current and its reference is frequency This function will yield an error if its argument is complex and has no reference Histogram real real Argi Vector Arg2 Number of bins Creates a histogram of argument 1 with the number of bins specified by argument 2 The bins are divided evenly between the maximum and minimum values in the argument Histograms are useful for finding information about waveforms that are difficult to determine by other means They are particularly useful for finding flat areas such as the flat tops of pulses as these appear as well defined peaks The Histogram function is used in the rise and
283. ion PRINT step 20u E Defaut DCOP Output all data Output at PRINT step Real time noise Enable realtime noise Define Monte Carlo and multi step analysis Enable multi step Define Selected mode None N Define Snapshots Advanced Options Help To set up the analysis first check the box on the right according to which analysis you wish to perform You can select more than one but usually it is easier to do just one at a time The following describes the most commonly used modes and how to set one up Transient The most useful and general mode First the bias point is found Then the circuit is simulated over a fixed time interval in steps of varying size according to circuit activity The circuit may contain any number of time varying voltage and current sources stimuli see Circuit Stimulus on page 46 to simulate external signals test generators etc Usually you only need to specify the Stop time specified at the top of the dialog box For information on the remaining options see Transient Analysis on page 176 DC Device Sweep A DC device sweep will sweep a specified device over a defined range and compute the DC operating point of the circuit at each point This allows for example the DC transfer function of the circuit to be plotted Note that all reactive elements are ignored in DC sweep 51 User s Manual To set up a DC Sweep select the DC Sweep ch
284. ion we describe some details of how the Verilog interface works VPI SIMetrix communicates with the Verilog simulator using the Verilog Procedural Interface or VPI VPI allows an external program to communicate with a Verilog simulator The diagram below shows the program structure SiMetrix Simulator Process Verilog Process S Metrix Simulator Interprocess communication 2 vsxd vpi Verilog Simulator vsxd vpi is a DLL shared library that is provided as part of SIMetrix This is loaded by the external Verilog simulator and runs in the Verilog process s memory space vsxd vpi uses the VPI interface to send events to the Verilog simulator to respond to 349 Simulator Reference Manual 350 events generated by the Verilog simulator and to interrogate the Verilog simulator about details of the user s Verilog module vsxd vpi is able to respond to events during the Verilog simulation that cause a change on an output port and send those changes to the SIMetrix simulator Conversely the SIMetrix simulator detects when there are changes on an input port and notifies vsxd vpi which then notifies the Verilog simulator vsxd vpi is also able to enumerate the ports and parameters of a Verilog module and report this information back to SIMetrix This process is performed before a simulation starts in order to build the final Verilog top level design Int
285. ircuit parameter such as a component reference e g R23 value e g 2 2K or model name e g BC547 All properties have a name a value and a number of attributes A property s value may be displayed on the schematic Most attributes determine how the value is displayed an exception is the protected attribute which determines whether a property is allowed to be modified A property can have any name as long as does not have spaces in it and any value However certain property names have a special meaning and impart a particular functionality on the component that owns it These special properties are described in the following table Note however that this is not an exhaustive list as many properties are used for special components and the behaviour they impart is defined in the script that is used to edit those components Chapter 4 Schematic Editor Property name Function ref value model Component reference E g R23 All circuit devices must have this property and its value must be unique Component value or model name E g BC547 All circuit devices must have this property This may be confusing What is described here is a property of name value not the property s value Single letter to signify type of device For list of signifying letters for each device supported by simulator see Summary of Simulator Devices on page 115 If absent the first letter of the component reference will be used instea
286. is being moved or copied see below You can also select a component or block then press the rotate button key to rotate in situ To mirror a component or block through the y axis press the Mirror toolbar button or F6 key To flip a component or block mirror about x axis press Flip button or press shift F6 43 User s Manual 44 Wiring There are a number of ways of placing a wire Method 1 Place the mouse cursor close to an unselected symbol pin or wire end Notice the cursor shape change to depict a pen symbol Now left click to mark the start point then left click again to mark the final point SIMetrix will automatically route the wire for you You can also mark intermediate points if you would prefer to define the precise route rather than accept the auto routed connection Method 2 If you have a three button mouse or scroll wheel mouse you can start a wire by clicking the middle button scroll wheel Clicking the middle button or scroll wheel a second time will complete the wire and start a new one Click the right button or press escape to terminate wiring Method 3 Start a wire by pressing F3 or double clicking the left button Single clicking the left button will complete the wire and start a new one Click the right button or press escape to terminate wiring Method 4 Press the Wiring tool button on the toolbar You can start a wire by single clicking the left button otherwise continue as described abov
287. istors J Choose Component Value Select Component Value Base 1 Series Decade 1k A E6 E12 a E24 Resut E 8 You can enter the value directly in the Result box or use the Base and Decade up down controls Additional Parameters Press Parameters button to edit additional parameter associated with the device such as temperature coefficients TC1 TC2 Refer to device in the Simulator Reference Manual for details of all device parameters Capacitors and Inductors Capacitors and inductors may be used in both SIMetrix and SIMPLIS modes Note that in SIMetrix mode a number of additional parameters may be specified These will not work with SIMPLIS and must not be specified if dual mode operation is required The following dialog will be displayed when you edit a capacitor or inductor Chapter 5 Components J Choose Component Value mx Device Value Initial Conditions Base 1 Series Open circuit Enable For Analysis Decade 1n a E6 Initial voltage Op E12 V Iransie I f gt m Is ok The device value is edited in the same manner as for resistors You can also supply an initial condition which defines how the device behaves while a DC operating point is calculated For capacitors you can either specify that the device is open circuit or alternatively you can specify a fixed voltage For inductors the device can be treated as a short circuit or you can define a constant current I
288. it Syntax LIB pathname pathname File system path name specifying a single file or by using a wildcard or a group of files If the path name contains spaces it must be enclosed in quotation marks 171 User s Manual 172 This control specifies a pathname to be searched for model and subcircuit libraries Any number of LIB controls may be specified and wild cards i e and may be used If a model or subcircuit is called up by a device line but that definition was not present in the netlist SIMetrix will search for it in files specified using the LIB control SIMetrix also supports another form of LIB used by model files designed for Hspice See the Simulator Reference Manual for details Drag and Drop to Schematic You can install a model file to a schematic by picking it up in windows explorer and dropping it onto the schematic window This will insert a LIB control see above with a path to the file you dropped This installs the model file to be local to that schematic Library Diagnostics When enabled library diagnostics display messages showing the progress of the location of device models To enable disable select FilelOptions General then Model Library tab Local Models You can also enter a model or subcircuit definition in the schematic s F11 window However if you enter a model in this manner it will only be available to that schematic Library Indexing Mechanism This is a te
289. it is not necessary to apply an AC specification to any source including the optional input referred source as it is with standard SPICE and many if not all of its derivatives Setting up an AC Noise analysis 1 Select menu SimulatorlChoose Analysis 2 Select Noise check box on the right 189 User s Manual 190 3 Select Noise tab at the top Enter parameters as described in the following sections Sweep Parameters Start value Stop value Points per decade Number of points Define Noise Parameters Output node Reference node Source name Defines sweep range stop and start values Defines sweep range The number of points of the sweep is defined per decade for a decade sweep For a linear sweep you must enter the total number of points Sets up desired sweep mode See Setting up a Swept Analysis on page 185 This is compulsory It is the name of the circuit node as it appears in the netlist Usually the schematic s netlist generator chooses the node names but we recommend that when running a noise analysis that you assign a user defined name to your designated output node To find out how to do this see Finding and Specifying Net Names on page 72 Optional Output noise is referred to this node This is assumed to be ground if it is omitted Optional Voltage or current source to which input source is referred Enter the component reference of either a voltage or current sourc
290. it widt A Delete axis Fit page Graph toolbar The above shows the function of each of the buttons on the graph toolbar These are referred to in the following sections Probes Fixed vs Random 222 Much of this section and some of the next have already been covered in Plotting Simulation Results on page 58 It is repeated here for convenience SIMetrix provides two approaches to creating plots of simulated results from a schematic The first approach is to fix voltage or current probes to the schematic before or during a run SIMetrix will then generate graphs of the selected voltages and or currents automatically Normally the graphs for fixed probes are opened and updated while the simulator is running The probes have a wide range of options which allow you to specify for example how the graphs are organised and when and how often they are updated These probes are known as fixed probes The second approach is to randomly probe the circuit after the run is complete You can also do this during a run by pausing first With this approach the graph will be created as you point the probe but will not be updated on a new run These probes are known as random probes You do not need to make any decisions on how you wish to probe your circuit before starting the run You can enter a circuit without any fixed probes run it then randomly probe afterwards Alternatively you can place a single fixed probe on an obvious point o
291. its it should run See page 50 below 4 Run simulator See Running the Simulator on page 58 5 Graph results See Plotting Simulation Results on page 58 The following paragraphs briefly describe these steps More details are given in other sections Simulation Modes SiMetrix or SIMPLIS If you have SIMetrix SIMPLIS you can set the schematic editor to one of two modes to select whether you are using the SIMetrix native SPICE simulator or the SIMPLIS simulator To choose the simulator mode select the menu FilelSelect Simulator then select which simulator you wish to use If the schematic is not empty and you change modes the program will check that all parts entered on the sheet are compatible with the newly selected simulation mode as not all parts will work in both modes Any that are believed not to be compatible will be highlighted and a warning will be issued To clear the highlighting select EditlUnhighlight This Sheet You will most likely need to replace those components but in some cases you may simply need to re enter the same component If you wish to enter a circuit that will work in both modes you should enter it in SIMPLIS mode and not use any of the components in the menu PlacelSIMPLIS Primitives Following this advice will not guarantee a circuit with dual mode simulation ability but will minimise the chance of placing a device that is compatible with only one of the simulators Using the Schematic
292. jl Cells SPROJECT Cells Using Symbolic Names Symbolic path constants may be used in the applications listed below In all cases a mechanism called automatic path matching is used which means that to use symbolic paths all you need to do is define the values in the project file then carry on working as before The automatic path matching algorithm attempts to match a user symbol or one of the EXEPATH or DOCSPATH system symbols to a part of the path being processed If a match is found the path name will be stored with the symbolic value Component paths If a component is placed using the full path option the automatic path matching mechanism described above will be invoked For example suppose the user symbol CELLS has the value C Projects Proj1 Cells and the component with path C Projects Proj1 Cells celllib1 inv sxsch is placed using the full path method The actual value of the schematic_path property will become CELLS celllib l inv sxsch The matching of C Projects Proj1 Cells to 7CELLS is performed automatically Note that automatic path matching will not be invoked for components placed using the relative path method Global model library file paths Model files installed globally can use symbolic paths The automatic path matching mechanism described above will be invoked when models are installed So if the model file C SPICELIB OnSemi mod and the symbol MODELLIB has the value C SPICELIB the model file path will be
293. k Q 15 You can add params to emphasise where the parameters start and also for compatibility with some other simulators E g params FREQ 12k Q 15 Note for information about passing parameters to a hierarchical block please refer to Passing Parameters Through a Hierarchy on page 78 Special Components Initial Conditions Initial conditions force a node to a fixed voltage or current during the calculation of the DC bias point There are two types of initial condition namely soft and hard Soft initial conditions apply a voltage through a fixed resistance Hard initial conditions apply a voltage directly without any resistance To Place a Soft Initial Condition 1 Select menu PlacelConnectorslInitial Condition 2 Place device at the desired location then select and press F7 Enter a suitable voltage To Place a Hard Initial Condition 1 Select menu PlacelFrom Symbol Library 2 Select device Connections Ics and Nodesets Initial Condition Hard 3 Place device at the desired location then select and press F7 Enter a suitable voltage Notes Soft initial conditions are implemented using the IC control and will also correctly apply an initial condition when Skip DC bias point is specified for a transient analysis The driving resistance for a soft initial condition is 1Q by default but can be altered using the ICRES simulator option To do this add OPTIONS ICRES nnn to the F11 window see Manual Entry of S
294. k at any voltage current or device power over the analysis time period You can also place fixed probes on the circuit before running the analysis which will cause the waveform at that point of the circuit to be automatically be displayed while the simulation is running or optionally after its completion Some of the other analysis modes are AC analysis which performs a frequency sweep DC sweep which ramps a voltage or current source and noise analysis which calculates total noise at a specified point and which components are responsible for that noise Tutorial 1 A Simple Ready to Run Circuit 22 This tutorial demonstrates a basic simulation on a ready to run to circuit All you need to do is load the circuit and press F9 to run it We will then make a few changes to the circuit and make some extra plots This tutorial demonstrates the basic features without having to get into the details of setting up a simulation Proceed as follows 1 Select the menu FilelOpen Schematic Select the schematic file TUTORIAL1 which you should find in the folder EXAMPLES TUTORIALS See Examples and Tutorials Where are They on page 21 Select Open to open this file A schematic window will open with the following circuit 5 6k ie As Amplifier Output CLOAD AC 1 0 Pulse 0 100m 0 10n 10n 5u This is a simple feedback amplifier designed to amplify a 100mV pulse up to Chapter 2 Quick Start around 50
295. l This is useful if you wanted to display a frequency instead of a period For a detailed description of this feature see Graph Symbolic Values on page 273 You can use any arithmetic operator along with many of the functions described in the Script Reference Manual in these expressions Style Show Absolute Clear check box to disable display of the absolute positions of the cursors Show Difference Clear check box to disable display of relative positions Automatic Internal External Style of dimension Internal means that the arrows will always be displayed between the cursors External means they will always be displayed outside the cursors In automatic mode the style will change according to the spacing and position Note if you clear both absolute and difference you will only be able to restore the display of the dimension by switching cursors off then on again Chapter 9 Graphs Probes and Data Analysis Font Select font used for readout text Properties Tab The properties tab lists all available properties of the CrosshairDimension object This will probably only be of interest if you are writing custom scripts to manipulate cursor dimensions More information on this subject can be found in the Script Reference Manual This is available as a PDF file on the install CD see Install CD on page 16 and may also be downloaded from our web site Status Bar Readout You can optionally have the cursor read out in th
296. l connections at the lower levels So every child schematic at lower levels would also need VCC pins Chapter 4 Schematic Editor However it is sometime convenient to hide these connections When there is only one supply for an entire design this can be done using global nets However in the scenario we described above there are two versions of VCC so we would not be able to use a global net in this case A solution to this is to use a feature of SIMetrix called Global Pins Global pins are defined during symbol definition Once a pin is defined as global a net of the same name will be available in all child schematics at all levels without the need for it to be explicitly passed Example 5 12 oy block1 sxsch block1 sxsch vec U1 vcc U2 b In Out In Out VEE VEE Sine 0 1 1k 0 0 vi jE o l Top level schematic 1K a block2 sxsch PinBin1 Block 1 vcc Ju at Pino z N1 L1 Pin VEE Block 2 In the above example VCC and VEE connections have been made in block2 without them having to be passed via the parent block1 The above trivial example is supplied as an example See Examples Hierarchy Global Pins 77 User s Manual 78 Creating Global Pins To define a global pin select the symbol editor menu Property Pin Global Pins Double click on the pin you wish to assign as global and select Yes Passing Param
297. l BUS1 F defaut Threshold kaw 0 8 D Stat 0 S m defaut Threshold E High 09 8 End 1 G E defaut Required if any bus signals are analog Define Plot Define Analog Wavefom Digtal display Decimal Range 1 Digital display Hex Offset 500n z Unts None Digtal display Binary Analog waveform Hold invalid states Define Bus Label This is how the curve will be labelled in the plot 237 User s Manual 238 Start End Defines which wires in the bus are used to created the displayed data The default is to use all wires Plot Type Decimal Hexadecimal Binary Each of these specifies a numeric display see below showing the bus values in the number base selected Analog waveform Specifies that the bus data should be plotted as an analog waveform Hold invalid states If checked then and invalid digital states found in the data will be replaced with the most recent valid state If not checked invalid states will be shown as an X in numeric displays This option is automatically selected for analog waveform mode Analog Thresholds These are required if any of the signals on the bus is analog These define the thresholds for converting to logic levels Threshold Low Analog voltage below which the signal is considered a logic zero Threshold High Analog voltage above which the signal is considered a logic one If a signal is above the lower threshold but below the upper threshold
298. l Inductance device The SIMetrix version is explained in the next section For the SIMPLIS equivalent see the SIMPLIS reference manual Coupling Factor The standard user interface for both saturable and ideal transformers provide only limited flexibility to specify inter winding coupling factor In the majority of applications coupling factor is not an important issue and so the standard model will suffice In some applications however the relative coupling factors of different windings can be important An example is in a flyback switched mode supply where the output voltage is sensed by an auxiliary winding In this instance best performance is achieved if the sense winding is strongly coupled to the secondary Such a transformer is likely to have a different coupling factor for the various windings You can use external leakage inductances to model coupling factor and this will provide some additional flexibility One approach is to set the user interface coupling factor to unity and model all non ideal coupling using external inductors In some cases it may be necessary to couple the leakage inductors Consider for example an E core with 4 windings one on each outer leg and two on the inner leg Each winding taken on its own would have approximately the same coupling to the core and so each would have the same leakage inductance But the two windings on the centre leg would be more closely coupled to each other than to the other windings
299. l Text Command Line F11 Window Graph Graph Caption Graph Free Text Legend Box Message Window Print Caption Schematic Schematic annotation Schematic caption Schematic free text Schematic user 1 4 View File Window Notes on Schematic Fonts Model display window in associate model dialog box Command line at top of command shell Schematic F11 window used for simulator commands Graph windows Graph Caption objects placed using Annotate Add Caption Graph Free Text object placed using Annotate Add Free Text Graph Legend Box object placed using Annotate Add Legend Box Bottom part of command shell Font used at base of printed schematic and graph Default for schematics Note that the size for all schematic fonts is relative The actual font size used also depends on current zoom level The font you select will be the size used for zoom magnification 1 0 as displayed in the status bar of the schematic Schematic used by bias annotation markers Schematic captions Popup menu Add Caption Schematic free text Popup menu Add Free Text Unassigned schematic fonts You can assign any of these fonts or in fact any of the other schematic fonts to any symbol property at the symbol definition stage You can also change the font assignment of any unprotected property on a schematic using the popup menu Edit Properties Window opened for viewing files such as the simulator list
300. l details of available probe options are described Select the probe and press F7 or menu Edit Part The following dialog will be displayed for voltage current power db and phase probes 224 Chapter 9 Graphs Probes and Data Analysis J Edit Probe Probe Options Axis Scales Axis Labels Curve label Persistence Power L4 0 F defaut Axis type Graph Auto select F Use separate graph Use separate Y axis Graph name Use separate grid Analyses Digtal T Trensient Axis name DC Sweep Display order 7 AC sweep Arbitrary string to specify order Colour 7 Use default Edit E Plot on completion only oer ae The elements of each tabbed sheet are explained below Probe Options Sheet Curve Label Text that will be displayed by the probe on the schematic and will also be used to label resulting curves Persistence If non zero curves created from the curve will have a limited lifetime The persistence value is the number of curves from a single probe that will be displayed at once the oldest being automatically deleted If set to zero they will never be deleted Persistence can also be set globally see Graph Probe Data Analysis on page 359 Axis Type Specifies the type of y axis to use for the curve Auto Select Will use main y axis unless its unit are incompatible E g plotting a current but the graph already has a voltage In that case a new y axis will be created alongside the ma
301. l not be saved In AC analysis the CPU time required to output data can be very significant relative to the solution time so you should be aware that checking this box may slow down the simulation significantly Note that this check box only affects AC analyses See Also AC in Simulator Reference Manual Chapter 7 Analysis Modes Example Both the examples shown in Sweep Modes on page 182 are AC analyses The following is a frequency sweep which is the traditional AC analysis mode This was performed on the circuit shown on page 184 with restail 1k 1 l Frequency sw eep of diff amp circuit 4 2 gt 2 1 i 400m 200m 10k 100k 1M 10M 100M 1G Frequency Hertz Noise Analysis Like AC analysis AC Noise analysis is a small signal mode The circuit is treated as linear about it s DC operating point and the contribution of all noisy devices to a designated output is computed The total noise at that output is also calculated and optionally the noise referred back to an input source may also be computed Like DC AC and Transfer Function it is a swept mode and can be operated in any of the 6 modes described in Sweep Modes on page 182 With some of these modes e g sweeping a resistor value it will be necessary for the DC operating point to be recalculated at each point while with others such as frequency sweep it is only necessary to calculate it at the start of the run Note that
302. launched By default it is called startup sxscr but this name can be changed with in the options dialog box FilelOptions General The startup file may reside in the script directory defined by ScriptDir option variable or in a user script directory defined by UserScriptDir option variable The most common use for the startup script is to define custom menus and keys but any commands can be placed there To edit the startup script select the FilelScripts Edit Startup menu item 387 User s Manual Index LIB 171 OUT file 278 PARAM 159 _param 160 700Extensions option variable 364 A abs function 319 ABSTOL 199 AC sweep analysis 188 SIMPLIS 212 ALL CAT 170 AlwaysUseMarkers option variable 364 Analog behavioural modelling laplace 148 non linear 146 Analog digital converter 144 Analysis modes AC sweep 188 choose analysis dialog 174 DC sweep 186 Monte Carlo sweep 185 multi step 200 noise 189 operating point 181 options 198 real time noise 193 sensitivity 197 SIMPLIS 206 AC 212 Periodic operating point POP 209 211 transient 207 specifying 50 174 sweep modes 182 186 sweeping devices 182 sweeping frequency 185 sweeping model parameters 183 sweeping parameters 183 388 Index sweeping temperature 183 transfer function 195 transient 176 181 restarting 179 transient snapshots 179 AnnoMinSuffix options variable 364 APPDATAPATH system path 352 Application data directory 355 arg functio
303. le Step Monte Carlo Sweeps An example of this type of run is shown on page 185 These runs produce only a single curve with each point in the curve the result of the Monte Carlo analysis With these runs you do not need to apply a goal function just enter the name of the signal you wish to analyse To illustrate this we will use the same example as shown on page 185 1 2 3 4 Open the example circuit Examples Sweep AC_Param_Monte Run simulation Select menu ProbelPlot Histogram Left click on pin of the differential amplifier E1 You should see R4_N appear in the box Now enter a after this then click on the pin of the E1 This is what should be in the box R4_N R3_N Close box You should see something like this 285 User s Manual 286 Mean 2 85301 Std Dev 30 3897m i Frequency counts 2 78 2 8 2 82 2 84 2 86 2 88 2 9 2 92 Voltage V 20mV div This is a histogram showing the distribution of the gain of the amplifier at 100kHz Goal Functions A range of functions are available to process curve data Some of these are primitive and others use the user defined function mechanism Primitive functions are compiled into the binary executable file while user defined functions are defined as scripts and are installed at functions at start up User defined functions can be modified and you may also define your own For more information refer to the Script Reference Manual This i
304. le from our web site 259 User s Manual Curve Measurements 260 Overview A number of measurements can be applied to selected curves The results of these measurements are displayed below the curve legend and are also printed Some of these measurements can be selected from the tool bar and more can be called directly from the Legend Panel s pop up menu Right click in Legend Panel see Elements of the Graph Window on page 221 The remainder may be accessed via the menu Measure More Functions or by pressing F3 Measurement functions may also be applied to Fixed Probes so that they are automatically updated when a simulation is repeated See Applying Measurements to Fixed Probes on page 264 for more details Note that the legend panel may be resized by dragging its bottom edge with the mouse In general to perform a measurement select the curve or curves then select measurement from tool bar or menu If there is only one curve displayed it is not necessary to select it Available Measurements A wide range of measurement functions are available Select menu Measure More Functions to see the complete list For more information see Using the Define Measurement GUT below Using the Define Measurement GUI The Define Measurement GUI is a general purpose interface to the measurement system and provides access to all measuremant functions along with a means to define custom measurements To open the De
305. le to annotate graphs for documentation purposes These are Curve Marker A single arrow line and item of text to identify a curve or feature of a curve Legend Box Box of text that lists all the names of curves currently displayed Text Box Box containing text message Free Text Similar to text box but without border and background Caption As free text but designed for single line heading Curve Markers Placing To place a curve marker select menu AnnotatelAdd Curve Marker A single curve marker should appear in the right hand margin of the graph Moving To move it place the mouse cursor at the arrow head you should see the cursor shape change to a four pointed arrow then left click and drag to your desired location When you release the marker it will snap to the nearest curve Moving Label To move the text label alone place the mouse cursor to lie within the text then left click and drag You will notice the alignment of the text with respect to the arrowed line change as you move the text around the arrow You can fix a particular alignment if preferred by changing the marker s properties See below 269 User s Manual 270 Deleting First select the marker by a single left click in the text The text should change colour to blue Now press delete key or menu AnnotatelDelete Selected Object Editing Properties Double click the marker s label or select then menu AnnotatelEdit Selected Objec
306. lected curves These are described below 267 User s Manual FFT of Selected Curve With a single curve selected select menu Plot Fourier of Selected Curve A new graph sheet will be opened with the FFT of the curve displayed To plot an FFT of the curve over the span defined by the cursor locations select select menu Plot Fourier of Selected Curve Cursor span Smoothed Curves With a single curve selected select one of the Plot More LP Filtered menus For Plot More LP Filtered Custom TC you will need to enter a time constant value A new curve will be displayed which is a filtered version of the selected curve The above functions will still work if you don t select any curves In this case you will be prompted for the curve on which to perform the operation This system uses a first order digital IIR filter to perform the filtering action Graph Zooming and Scrolling 268 Zooming with the Mouse To zoom in on a portion of a graph place the cursor at the top left of the area you wish to view press and hold the left mouse key then move cursor to bottom right of area and release left key The axes limits will be modified appropriately If the graph has multiple stacked grids you should be sure that the first left click is within the area of the grid you wish to zoom You will notice a thin grey line separating each grid You should start the mouse drag within the grey lines for the chosen axis You can
307. led your own models see Parts Management Installing Models below you will always find them listed under the category All User Models and if installed within the last 30 days under Recently Added Models If you select a part under All User Models or Recently Added Models you may be presented with the Associate Model dialog box This will happen if SIMetrix is unable to determine what symbol to use for the model This is explained in Placing New Model on Schematic on page 165 Chapter 6 Device Library and Parts Management Parts Management Installing Models Overview The process of installing third party SPICE models has always been a fundamentally tricky one The difficulty has been associating the SPICE model which is the electrical definition of the device with the schematic symbol which is the pictorial representation of it A model provides an electrical description of the device but not what schematic symbol to use nor what category it should be in the parts browser SIMetrix is able to determine this for itself if the device is implemented using a MODEL statement as all MODELs refer to a particular type of device NPN NMOS Diode etc Devices implemented as subcircuits however remain a problem as there is nothing in a SUBCKT definition which tells SIMetrix what the device is For example a three terminal regulator and a power MOSFET use identical syntax SIMetrix can t
308. linear passive devices 151 generic ADCs and DACs 144 generic digital devices 145 laplace transfer function 148 non linear transfer function 146 Functions full list 317 G Global nets 76 Global pins 76 GlobalCatalog options variable 369 Goal functions 286 full list 286 288 Graph cursors 254 259 changing styles 257 displaying 255 freezing 256 moving 255 moving to peak or trough 256 readout 257 Graph toolbar 222 GraphExtension option variable 382 Graphs 221 annotation 269 272 AutoAxis 248 captions and free text 272 changing curve weight 359 changing digital axis height 359 copying to clipboard 275 creating new axes 249 creating new grids 249 cursors 254 259 see also Graph cursors deleting axes and grids 249 deleting curves 253 editing axes 250 hiding curves 253 highlighting curves 254 logarithmic 227 242 392 Index measurements 260 moving curves 249 multiple y axes 246 naming curves 254 plotting 221 printing options 358 saving and restoring 277 scrolling 268 selecting axes and grids 249 selecting curves 253 showing curves 253 zooming 268 GridPrintWidth option variable 369 Grids creating new 249 deleting 249 reordering 251 Group curves multi step analysis feature 201 Group delay plotting 229 GroupDelay function 322 GroupPersistence option variable 252 370 H Hamming FFT window 236 handle property 96 Hanning FFT window 236 HideSchematicGrid option variable 370 Hierarchical
309. ll CD on page 16 293 User s Manual 294 PeakToPeak PeakToPeak data xStart xEnd Returns the difference between the maximum and minimum values found in the data within the interval xStart to xEnd If xStart is omitted it defaults to the x value of the first data point If xEnd is omitted it defaults to the x value of the last data point Implemented by built in script uf_peak_to_peak Source may be obtained from the install CD see Install CD on page 16 Period Period data threshold Returns the period of the data Refer to diagram for the Duty function on page 289 The Period function returns X3 X1 Default value for threshold is Ymax Ymin 2 Where Ymax largest value in data and Ymin in smallest value in data Implemented by built in script uf_period Source may be obtained from the install CD see Install CD on page 16 PhaseMargin PhaseMargin data phaseInstabilityPoint Finds the phase margin in dB of data where data is the complex open loop transfer function of a closed loop system The phase margin is defined as the angle by which the open loop phase shift of a system must increase in order to become unstable phaselnstabilityPoint is the phase at which the system becomes unstable This is used to allow support for inverting and non inverting systems If data represents an inverting system phaselnstabilityPoint should be zero If data represents a non inverting system phaselns
310. log box writes to this file In SIMetrix versions 5 2 and earlier this file was called USER CAT SIMetrix will automatically import data from USER CAT to USER_V2 CAT if USER CAT is present OUT CAT Resides in application data directory see Application Data Directory on page 355 This is what is actually used by the parts browser to select and place components It is generated by the associate model dialog box from information in ALL CAT USER_V2 CAT and installed models It will also be automatically created by the parts browser if it does not already exist You can also force it to be rebuilt at any time by selecting menu File Model Library Re build Catalog File Format Catalog files are text files Each line provides data about a single device in semi colon delimited fields The fields are as follows Field 1 Device name as it appears in browser This may optionally be followed by a comma followed by the number of terminals for the model Chapter 6 Device Library and Parts Management Field 2 Symbol name Field 3 Model property X for subcircuits as appropriate for other devices This field is empty in ALL CAT and USER_V2 CAT it is determined automatically from electrical model when OUT CAT is built Field 4 Category Field 5 Sub category currently not used Field 6 Pin mapping order Filed 7 Not used When you select OK your edits will be written to the USER_V2 CAT file see above table This is in the same fo
311. lour Even if printing to a colour printer curves will still be printed using markers and variable line styles to differentiate them They will also be printed in colour This is useful when creating on line documents e g using Adobe Acrobat Distiller which might subsequently be viewed on line or printed out Graph Probe Data Analysis Probe update times Plots created from fixed probes are updated on a regular basis This controls how frequently and when it starts Period Update period in seconds Start Start delay in seconds Fixed probe global options Sizes Default persistence Sets the default persistence for fixed probes This is number of curves from previous simulations that remain after a simulation Tf set to 1 previous results are deleted If set to zero all results are retained Persistence can also be set individually for each probe See Probe Options Sheet on page 225 for details Curve weight Thickness of displayed curves Curves display much quicker if this value is set to 1 but are clearer but can lose detail if set to 2 Digital Axis Height Sets height of axes in mm used to plot digital traces Min grid height When a grid is added to a graph window existing grids are reduced in height to accommodate the new one But they won t be reduced to a height lower than specified by this setting When this limit is reached the vertical space will be increased by allowing the window to scroll Te
312. ls Where are They on page 21 Pick the file up and drop into the SIMetrix command shell That is drop it in the window where SIMetrix messages are displayed If you can t see the command shell because it is obscured select any SIMetrix window then press the space bar A message box will appear asking you to confirm you wish to install the file Click Ok The message Making device catalog This may take some time please wait will be displayed At this stage SIMetrix knows where to find our fictitious devices You will find that it also knows about the NPN transistor as the following demonstrates 1 Open an empty schematic 2 Press control G or select menu PlacelFrom Model Library You should see window displayed with the caption Select Device 3 Select the Recently Added Models category from the top of list shown on the left hand side 37 User s Manual 4 Select SXN1001 from the listed items on the right hand side This is what you should see Recently Added Models a All User Models SXOA1000 All Models Analog MSI Analog switches Buffers Comparators Digital Flip flops Digital MSI Digital Analog interfaces Diode Drivers Gates Gates An IGBTs m w i Cee ees ae C Users rw Documents S Metrix Examples Tutorials Tutorial3 mod Category NPN 5 Press Place to place the device on the schematic
313. lso offers an Octal sweep method but this is not supported by the Choose Analysis Dialog Each of the sweep modes is explained in more detail below Device Sweep In this mode the principal value of a single device is swept The analysis definition must specify the component reference for the device The following types of device may be used Device Value swept Capacitor Capacitance Diode Area Voltage controlled voltage Gain source Current controlled current Gain source Voltage controlled current Transconductance source Current controlled voltage Transresistance source Current source Current Chapter 7 Analysis Modes Device Value swept JFET Area Inductor Inductance Bipolar Transistor Area Resistor Resistance Lossless Transmission Line Impedance Voltage source Voltage GaAs FET Area Temperature Global circuit temperature is swept Model Parameter Similar to device sweep except applied to a named model parameter Both the model name and the parameter name must be specified Special Note It is recommended that any model parameter being swept is also specified in the MODEL parameter list In most cases it isn t actually necessary but there are a few instances such as for terminal resistance parameters where it is necessary Parameter A user named variable that can be referenced in any number of expressions used to define model or device parameters Here is an example See Examples Sweep AC_Par
314. ly function which will not return an error if supplied with an empty value Empty variables are returned by some functions when they cannot produce a return value All other functions and operators will yield an error if presented with an empty value and abort any script that called it In real complex Returns the natural logarithm of the argument Chapter 11 Command and Function Reference Using In with Negative or Complex Values If the argument is real and 0 or negative an error will result If the argument is complex it will return a complex result even if the imaginary part is 0 and the real part negative E g in 1 will produce an error But 1n 1 0 will give the answer 0 3 1415926535897931 jm An error will always occur if both real and imaginary parts are zero Using In with AC Analysis Data See notes under log10 function below log10 real complex log real complex Returns log to base 10 of argument In general we recommend using log10 rather than log Software products of all types vary in their interpretation of log Some treat it as log to the base 10 and others treat it as log to the base e By using log10 there will never be any doubt Using log10 with Negative or Complex Values See notes above under In function Using log10 with AC Analysis Data The data output by the simulator when running an AC or TF analysis is complex As described in Using In with Negative or Complex Val
315. ly the simplest example of a generic component There are some components that have characteristics of both types CMOS IC designers would use MOSFETs defined by a model but will then customise it with length and width parameters Saturable inductors have an underlying model to describe the core s characteristics but a number of user defined parameters to define the geometry and air gap Numbered components need a model which is usually stored in the model library Refer to Device Library and Parts Management on page 162 for details This chapter is concerned only with devices at the schematic level Many of these devices are implemented directly by the simulator For example the simulator has a bipolar transistor model built in and such devices can be defined with a set of simulator parameters However not all devices are implemented directly by the simulator It does not for example have an operational amplifier device built in These components are constructed from a number of other components into a subcircuit The devices built in to the simulator are described in the Simulator Devices chapter of the Simulator Reference Manual Numbered Components 118 Numbered components may be accessed via the Parts Browser Select menu PlacelFrom Model Library to open it Chapter 5 Components J s Recently Added Models RF522 inf5852 RF621 All User Models RF523 irf5m3205 RF622 All Mod
316. ly which run a particular curve is associated with To do this proceed as follows 1 Switch on graph cursors Cursors Toggle On Off menu 2 Pick up the main cursor the one with the short dashes and place it on the curve of interest To pick up a cursor place mouse cursor at intersection press left key and drag 3 Select Show Curve Info menu Information about the curve will be displayed in the command shell This is an example of what will be displayed Source group acl Curve id 4 Run number 49 The information of interest here is the Run number With this you can look up in the log file details of the run i e what values were used for each component and parameter You can also obtain the seed value used so that the run can be repeated See Setting the Seed Value on page 337 Plotting a single Curve If you wish to plot a single curve in a Monte Carlo set you must obtain the run number then use the ProbelAdd Curve menu to plot an indexed expression We use an example to explain the process Using the Chebyshev filter example let s suppose that we wish to plot the curve of the filter output created by run 49 alone without the remaining curves Proceed as follows 5 Chapter 12 Monte Carlo Analysis Run the chebyshev filter example as explained at the beginning of this chapter Select menu ProbelAdd Curve Click on the output of the filter You should see C4_P entered in the Y expression box You m
317. lysis that uses snapshot data are already present in the circuit before the transient run starts In particular of course you must make sure that an AC source is present An error message will be output if there are any topological differences between the circuit that generated the snapshot data and the circuit that uses it If there are only component or model parameter differences then the snapshot data may be accepted without error but at best the results will need careful interpretation and at worst will be completely erroneous Generally if you change a component that affects the DC operating point then the results will not be meaningful If you change only an AC value e g a capacitor value then the results will probably be valid How Snapshots are Stored The snapshot data is stored in a file which has the default name of netlist sxsnp where netlist is the name of the netlist used for the simulation When using the schematic editor this is usually design net so the usual name for the snapshot file is design sxsnp You can override this name using the SNAPSHOTFILE OPTIONS setting although there is rarely any reason to do this The snapshot file is automatically deleted at the start of every transient run The SaveSnapShot command always appends its data to the snapshot file so that any pre defined snapshots are preserved When snapshot data is applied to a subsequent small signal analysis the snapshot file is read and checked that it
318. m Distribution The default distribution for device tolerances is Gaussian with the tolerance representing a 30 spread This can be changed to rectangular using two simulator options These are MC_ABSOLUTE_RECT If set absolute tolerances will have a rectangular distribution MC_MATCH_RECT If set matching tolerances will have a rectangular distribution Distributions can be specified on a per component basis or even a per parameter basis by using distribution functions in an expression See the Monte Carlo Analysis chapter of the Simulator Reference Manual for details Running Monte Carlo 336 Overview There are actually two types of Monte Carlo analyses These are 1 Single step Monte Carlo sweep 2 Multi step Monte Carlo run 1 above is applicable to AC DC Noise and Transfer Function analyses 2 can be applied to the same analyses in addition to transient analysis An example of 1 can be seen on page 185 This was a run where the gain at a single frequency was calculated 1000 times with the Monte Carlo tolerances applied This used AC analysis with the Monte Carlo sweep mode one of the six modes available Only a single curve is created hence the name single step An example of 2 is the example at the beginning of this chapter Here a complete frequency sweep from 1kHz to 100kHz was repeated 100 times creating 100 curves Setting up a Single Step Monte Carlo Sweep 1 Select schematic menu SimulatorlChoose Analysis
319. m a script is a method of creating symbols programmatically and is useful for creating symbols for devices that have some variable characteristic An example is a transformer that can have a varying number of windings and indeed this technique is employed to create symbols for the built in transformer models For full documentation on how to create a symbol from a script refer to the Script Reference Manual This is available as a PDF file on the install CD see Install CD on page 16 and can also be downloaded from our web site 93 User s Manual Properties 94 Overview Properties are one of the schematic editor s most important concepts They are actually used for a number of purposes but the most importantly they are used to determine how a schematic device behaves during simulation A property tells the simulator what type of device it is resistor BJT sub circuit etc another property specifies a device s value or model name and for a hierarchical block a property specifies the file location of the underlying schematic For many applications you only need to understand the meaning of ref value and model properties These are explained below but also in Adding Standard Properties on page 90 It is also useful but not essential to understand the schematic_path property used in hierarchical blocks What is a Property A Property is an item of text that is attached to a schematic component to specify some c
320. m the graph To hide a curve or curves select it or them then press the Hide selected curves button To show it or them again press the Show selected curves button 253 User s Manual Re titling Curves You can change the title of a curve by selecting it then pressing the Name curve button This will change the name of the curve as displayed in the legend panel Above main graph area and below toolbar Highlighting Curves You can highlight one or more curves so that they stand out from the others This is useful if there are many overlapping curves displayed To Highlight Curves 1 Select the curves you wish to highlight then press H or menu CurveslHighlight Selected Curves To Un highlight Curves 1 Select the curves you wish to un highlight then press U or menu Curves Unhighlight Selected Curves To Unhighlight All Curves 1 Select menu Curves Unhighlight All Curves Graph Cursors 254 Overview Graph cursors can be used to make measurements from waveforms In their default configuration they consist of two dimensioned crosshairs as shown below Chapter 9 Graphs Probes and Data Analysis 254 2373n 4 757869u lt 4 503632u gt 401 301 201 201 94 3299m 30 V 292 533m Oy fe cir ici ets iis mses es i S Mae EEE wee a 386 863m Reference Cursor 0 3 j i Time uSecs 500nSecs div A p Main Cursor The curso
321. mOfSquares real real Returns root sum of squares of 329 reall argument over specified range sign real Return sign of argument 329 sin real complex Sine 329 sqrt real complex Square root 329 tan real complex Tangent 329 Truncate real real real Returns vector that is a sub 329 range of supplied vector unitvec real Returns vector of specified length 330 whose elements are all 1 vector real Returns vector of specified length 330 with each element equal to its index XFromy real real real Returns array of values 330 specifying horizontal locations where specified vector crosses given y value YFromX real real real Returns array of values 330 specifying the vertical value of the specified vector at the given x value Function Reference Only a few of the approx 200 functions are documented here For the rest please refer to the Script Reference Manual This is available as a PDF file on the install CD see Install CD on page 16 and may also be downloaded from our web site The ones detailed here are the functions that accept and return numeric values and that could conceivably used for graph plots abs real complex Returns absolute value or magnitude of argument This function is identical to the mag function arg real complex Same as phase page 328 except the result wraps at 180 180 degrees 319 User s Manual 320 arg_rad real complex Same as phase_rad page 328 exc
322. matic to fill the window prior to copying to the clipboard After copying to the clipboard the schematic can be pasted into another application such as a word processor Annotating a Schematic You can add a caption or free text to a schematic The only difference between them is the font style and justification Captions use a heavy font and are centre justified Free text use a smaller font and are left justified To place a caption or free text use the popup or fixed menus EditlAdd Caption or EditlAdd Free Text respectively Note you can use the enter key to add a new line The actual fonts used can be changed with FilelOptions Font Note the fonts are global and not stored with the schematic Chapter 4 Schematic Editor Assigning Component References Standard Behaviour As you place components on a schematic they are automatically assigned a component reference R1 Q42 C11 etc These references are assigned in sequence and breaks in the sequence are reused So if you place resistors on the schematic R1 R2 R3 and R4 then delete R2 the next resistor placed will use the reference R2 that has become available Setting Start Value By default auto assigned references start at 1 You can change this using the AnnoMinSuffix option variable see page 364 For example type this at the command line Set AnnoMinSuffix 100 Auto assigned component references will now begin with 100 Assigning By Position You
323. maximum duty cycle Output low voltage Low voltage of output pulse Output high voltage High voltage of output pulse Mximum duty cycle Maximum duty cycle This may not be higher than 0 999 Generic ADCs and DACs Generic data conversion devices are available from the menus PlacelDigital GenericlADC and PlacelDigital GenericIDAC J Define A D Converter mx Number of bits E a Timings Convert time lu 0 Max conversion rate 4 gt 2Meg Input Offset volts 0 Range volts 5 J OD o J Define D A Converter Number of bits E S Timings Output slew time 100n S Output Offset volts 0 8 Range volts 5 a Chapter 5 Components These devices are implemented using the simulator s ADC and DAC models For details of these refer to the chapter Digital Mixed Signal Device Reference in the Simulator Reference Manual The controls in these boxes are explained below Number of bits Resolution of converter Values from 1 to32 Convert time ADC Time from start convert active rising edge to data becoming available Max conversion rate ADC Max frequency of start convert Period 1 f must be less than or equal to convert time Output slew time Whenever the input code changes the output is set on a trajectory to reach the target value in the time specified by this value Offset voltage Self explanatory Range Full scale range in volts Generic Digital Devices A number of gen
324. mbol aa Edit Pin Names Hectrical Model SXOA1000 From C Users jrw Documents SIMetrix Examples Tutorials Tutorial3 mod line 14 se se ee se ae se se I2 subckt SXOA1000 VINP VINN VOUT VCC VEE gt m Opamp Negative supply j Positive supply Inverting input Non inv input l D2_N VEE 100u X Associate Model dialog box In the top left hand group you select the device or devices that you wish to associate The drop down box at the top has a list of categories Usually you would select a device or devices in the Unknown category but you can also edit the association of known devices in other categories Once the category has been selected a list of devices in that category will be displayed in the list box below You should then select a device or devices to associate To select multiple devices hold the control key down while selecting Note that you will not be allowed to select multiple devices that have different numbers of pins To help you determine what type of device it is its electrical model is displayed in the window that covers most of the lower half of the dialog box You must now define the Category symbol and if necessary the pin order for the device This is done using the top right hand group of controls titled Choose Symbol Category Select an appropriate category and symbol N
325. me when_to_enable Specify key or key combination to activate menu Key description is placed on right hand side of menu item Use any of the codes specified in DefKey on page 309 except key pad codes Note that DefKey has precedence in the event of the key or key combination being defined by both DefKey and DefMenu Composed of strings separated by pipe symbol l First name must be one of the following Note that these are case sensitive under Linux Shell Command shell menu Schem Schematic popup menu Simetrix Schematic popup menu SIMetrix mode only Simplis schematic popup menu SIMPLIS mode only Graph Graph popup menu GraphMain Graph fixed menu SchemMain Schematic main menu SimetrixMain Schematic main menu SIMetrix mode only SimplisMain Schematic main menu SIMPLIS mode only Symbol Symbol editor popup menu SymbolMain Symbol editor fixed menu This must be followed by at least two l separated values for main menus and at least one l separated value for popup menus Each name describes one level in the menu hierarchy Use the amp symbol to define an underlined ALT key access letter mou To define a menu separator use the item text Note that if a menu name contains spaces it must be enclosed in quotation marks A boolean expression specifying under what circumstances the menu should be enabled The menu text turns grey when disabled If omitted the menu will always be enabled This is
326. mended that any schematics are saved before a run is commenced especially if the run is expected to take a long time SIMPLIS If the schematic is in SIMPLIS mode the procedure described above will start the SIMPLIS simulator A window showing the progress of the SIMPLIS simulation will be displayed Please refer to the SIMPLIS Reference Manual for more information about this display SIMPLIS can be aborted by pressing the Abort button in the progress window SIMPLIS cannot however be paused and resumed Plotting Simulation Results Overview SIMetrix provides two methods of creating plots of simulated results 58 Chapter 3 Getting Started The first approach is to fix voltage or current probes to the schematic before or during a run SIMetrix will then generate graphs of the selected voltages and or currents automatically The probes have a wide range of options which allow you to specify for example how the graphs are organised and when and how often they are updated The second approach is to randomly probe the circuit after the run is complete You can also do this during a run by pausing first With this approach the graph will be created as you point the probe but will not be updated on a new run You do not need to make any decisions on how you wish to probe your circuit before starting the run You can enter a circuit without any fixed probes run it then randomly probe afterwards Alternatively you can place say
327. method for transferring curves that uses very little memory even if the curve is large Also if you copy a curve the data itself is not copied internally the two curves just reference the same data This makes copying a memory efficient operation Chapter 9 Graphs Probes and Data Analysis To Move a Curve to a New Graph Sheet 1 Select the curve or curves you wish to move 2 Select menu EditlCut 3 Either create a new graph sheet to receive the new curves use F10 or switch to an existing graph sheet 4 Select menu EditlPaste To Copy a Curve to a New Graph Sheet 1 Select the curve or curves you wish to move 2 Select menu EditlCopy 3 Either create a new graph sheet to receive the new curves use F10 or switch to an existing graph sheet 4 Select menu EditlPaste Exporting Graphics You may export schematic graphics to other applications such as word processors or drawing programs You can do this via the clipboard windows only see Copying Graphics to the Clipboard above or by writing out to a file To export waveform graphics to a file select the graph menu File Save Picture then select the format of your choice using the Save as type drop down box The choices are 1 Windows Meta File EMF and WMEF This is only available in Windows versions Nearly all windows applications that support graphics import will accept this format Note that this is a scalable format and therefore suitable for high
328. metrix_intro ver SIMetrix Intro the free demo version where ver is the SIMetrix version number e g 5 50 On Windows the directory is at one of these locations sys_application_data_dir SIMetrix Technologies SIMetrixxx full production versions sys_application_data_dir SIMetrix Technologies SIMetrixIntroxx SIMetrix Intro where xXx is a three digit code representing the SIMetrix version number e g 620 for version 6 20 sys_application_data_dir is a system defined location The following table shows typical locations for all supported Windows systems Operating Path System Windows 2000 C Documents and Settings username Application Data Windows XP Windows Vista C Users username AppData Roaming Windows 7 username is the log on name currently being used The above are only typical locations on English language versions of Windows The user or system administrator may move them and also the names used may be different for non English versions of Windows With full versions of SIMetrix you can locate the SIMetrix application data directory by typing the following command at the command line Show TranslateLogicalPath ssxappdatapath Specifying Other Locations for Config Settings You can specify alternative locations for the configuration settings This can be done with the c switch on the command line or ConfigLoc setting in the startup ini file See SIMetrix Command Line Parameters on page 354
329. mporary data file delete Simulation data is stored in data files that are placed in the temporary data directory see file locations below These options control when these data files are deleted 359 User s Manual 360 Histogram style Cursor readout How data is stored Never Temporary files are never deleted but will be overwritten in subsequent sessions Not recommended unless you only ever do short simulations When S Metrix starts All temporary files are deleted when SIMetrix starts When SIMetrix closes All temporary files are deleted when SIMetrix is shut down While using SIMetrix you can recover earlier simulation runs Normally only the 3 most recent are kept but earlier ones can be recovered from the TEMPDATA directory using FilelDatalLoad When data is no longer needed This is the most aggressive delete method and is recommended if you do many long runs or and have limited disc space By default the 3 most recent runs are kept but with the other options above the data files are not deleted when the data is not needed but links to the data in them are released See explanation below If this option is set the data files are deleted as soon as they become out of date optimising use of disc space at the expense of not being able to recover old data Controls the curve style used for histogram displays Stepped Displays a flat line for the width of each bin Similar to a bar graph Smooth Jo
330. mportant note to experienced SPICE users The initial condition values above do not require the UIC or Skip DC bias point option to be set This implementation of initial condition is a new feature not found in standard SPICE If an initial condition for a capacitor is defined it will behave like a voltage source during the DC operating point calculation Similarly an inductor will behave like a current source if it has an initial condition defined Infinite Capacitors and Inductors The infinite capacitors and inductors are often useful for AC analysis To place an infinite capacitor select menu Place Passives Infinite Capacitor To place an infinite inductor select menu Place Magnetics Infinite Inductor The infinite capacitor works as follows 1 During the DC bias point calculation it behaves like an open circuit just like a regular finite capacitor 2 During any subsequent analysis it behaves like a voltage source with a value equal to the voltage achieved during the the DC bias point calculation The infinite inductor behaves as follows 1 During the DC bias point calculation it behaves like a short circuit just like a regular finite inductor 2 During any subsequent analysis it behaves like a current source with a value equal to the current achieved during the the DC bias point calculation These components allow you to close a feedback loop during the DC bias point then open it for any subsequent analysis 1
331. ms is the same except that you should use the menu ProbelHistogram instead Here is another example This is a design for an active band pass filter using the simulated inductor method See Examples MonteCarlo 768Hz_bandpass sxsch We want to plot a histogram of the centre frequency of the filter 283 User s Manual 284 The example circuit has been set up to do 100 runs This won t take long to run less than 10 seconds on most machines This is the procedure 1 2 3 4 Run the simulation using F9 or equivalent menu Select menu ProbelHistogram Left click on the output of the filter This is the junction of R1 and C2 You should see R1_P appear in the expression box We must now modify this with a goal function that returns the centre frequency The function CentreFreq will do this This measures the centre frequency by calculating the half way point between the intersections at some specified value below the peak Typically you would use 3dB Modify the value in the expression box so that it reads CentreFreq Rl_p 3 At this stage you can optionally modify the graph setting to enter your own axis labels etc Now close the box This is what you should see Frequency counts Chapter 9 Graphs Probes and Data Analysis 730 740 750 760 770 780 790 Frequency Hertz 10Hertz div Note that the mean and standard deviation are automatically calculated Histograms for Sing
332. much more easily identified Even if a problem cannot be reproduced then this gives some clues It means that it is caused by something that is not modelled a wiring parasitic perhaps Simulation is extremely useful for testing ideas at the system level Sometimes it is not easy to test a concept because the hardware to implement it is very costly or time consuming to build It may even be that you don t know how to implement the idea in hardware at all The alternative is to design a model and simulate it with a computer Once it has been established that the concept is viable then attention can be given to its implementation If it proves not to be viable then a great deal of time will have been saved Chapter 1 Introduction System Requirements Operating System Windows 32 bit versions The following are supported Windows 7 Home Premium Professional Enterprise Ultimate Windows Vista Home Home Premium Ultimate Business Enterprise Windows XP Home and Professional Windows 2000 There are no service pack requirements for any of the above The 32 bit version will also run on any of the systems listed under Windows 64 bit version below Windows 64 bit version The following are supported Windows 7 Home Premium Professional Enterprise Ultimate x64 Edition Windows Vista Home Home Premium Business Enterprise Ultimate x64 Edition Windows XP Professional x64 Edition There are no service pack requirements for any of the above
333. mulator snapshot files SymbolExtension lib Binary symbol files TextExtension txt net cir mod Text files ldf sxscr lib lb cat Toolbar Buttons The buttons displayed on each of the standard toolbars are defined with an option variable that is one for each toolbar The value of the option consists of a series of semi colon delimited button names A complete list of button names and full information concerning user defined toolbars can be found in the Script Reference Manual The toolbar option variable names are listed below Option name Description ComponentButtons Schematic parts in SIMetrix mode CommandShellMainButtons Command shell toolbar SIMPLISComponentButtons Schematic parts in SIMPLIS mode SchematicMainButtons Schematic main toolbar SchematicFileButtons Schematic file operations toolbar SymbolMainButtons Symbol editor toolbar GraphMainButtons Graph window toolbar Chapter 14 Sundry Topics Startup Auto Configuration Overview When SIMetrix is started for the first time it automatically sets up its configuration to default values Details of this process are provided in the following sections There are a number of settings that can be made to control this process and these are also explained What is Set Up During this phase the following is set up 1 Installs system supplied symbol libraries 2 Installs system supplied model libraries 3 Migrates configuration from earlier installed versions if available
334. multiple sheets are chosen a small overlap will be included Fixed grid means that the schematic s grid will be mapped to a fixed physical size on the paper The sizes are in inches 1 inch 25 4mm So 0 3 means that 1 grid square on the displayed schematic will be 0 3 inches or 7 5mm on the printed sheet Printing a Hierarchical Schematic 1 Select menu FilelPrint Hierarchy 2 You will be presented with a complete list of schematics used in the current hierarchy Select the schematics you wish print and Ok 3 Select options as appropriate then Ok File Operations 80 Saving For normal save operations use the FilelSave or FilelSave As menus To save all the sheets currently open use FilelSave All Chapter 4 Schematic Editor Exporting Schematic Graphics You may export schematic graphics to other applications such as word processors or drawing programs You can do this via the clipboard windows only see Copying to the Clipboard on page 70 or by writing out to a file To export schematic graphics to a file select the schematic menu File Save Picture then select the format of your choice using the Save as type drop down box The choices are 1 Windows Meta File EMF and WMF This is only available in Windows versions Nearly all windows applications that support graphics import will accept this format Note that this is a scalable format and therefore suitable for high resolution printing 2 Scalabl
335. n 319 arg_rad function 320 atan function 320 AutoStartWire options variable 364 AutoWireEnabled options variable 364 AWAlIlowRouteThruConnected options variable 364 Axes creating new 249 deleting 249 editing 250 reordering digital 251 selecting 249 AxisPrintWidth option variable 365 B Bandwidth function 288 Bias Point 278 BiasAnnoPrecision options variable 365 BiScriptDir option variable 353 365 Blackman FFT window 236 Bode plot 224 BPBW function 288 BuildAssociations options variable 365 BuildModelLibs options variable 365 BuildPreferenceSettings options variable 365 BuildSymbolLibs options variable 365 Bus connections see Schematic bus connections C CachePathSymbols options variable 365 CancelOnFocusLost option variable 366 Capacitor editing values 134 initial condition 135 non linear 151 sweeping 182 389 User s Manual Catalog files 170 ALL CAT 170 OUT CAT 170 USER CAT 170 CatalogExtension option variable 382 CentreFreq function 289 Chokes 130 see also Inductor Choose analysis dialog 174 Circuit rules 45 Circuit stimulus 46 Clipboard copying graphs 275 copying schematics 70 Colours customising 385 Command history 300 Command line 300 Commands full list 309 ComponentExtension option variable 382 Configuration settings 355 Core materials 130 cos function 320 Current plotting 60 Current source controlled 137 fixed 137 sweeping 182 CursorDisplay option variable 366 Cursors g
336. n an analysis on a netlist created by hand or perhaps with a third party schematic entry program To run a netlist in synchronous mode select the command shell menu Simulator Run Netlist then locate the netlist file To run a netlist in asynchronous mode select the command shell menu SimulatorlRun Netlist Asynchronous then locate the netlist file See Running Analyses in Asynchronous Mode above for further information about running asynchronous analyses Transient Analysis 176 In this mode the simulator computes the behaviour of the circuit over a time interval specified by the stop time Usually the stop time is the only parameter that needs specifying but there are a number of others available Setting up a Transient Analysis 1 Select menu SimulatorlChoose Analysis 2 Select Transient check box on the right Chapter 7 Analysis Modes 3 Select Transient tab at the top Enter parameters as described in the following sections Transient Parameters Enter the stop time as required Note that the simulation can be paused before the stop time is reached allowing the results obtained so far to be examined It is also possible to restart the simulation after the stop time has been reached and continue for as long as is needed For these reasons it is not so important to get the stop time absolutely right You should be aware however that the default values for a number of simulator parameters are chosen according
337. n disable the smart wiring algorithm altogether in which case the smart wiring procedure will place wires in a similar fashion to the manual wiring methods Secondly there is an option that controls whether or not the smart wiring algorithm is allowed to route wires through existing wires that are connected to the start and end points By default this option is on i e the smart algorithm is allowed to route through connected wires If the option is off the algorithm will not allow any wires in the route to connect to any existing wire regardless of what it is connected to In general we recommend that the option is left switched To change the smart wiring options select menu File Options General The two wiring options are in the section titled Wiring Manual Wiring Procedure If you have a three button mouse you can start a wire by clicking the middle button Clicking the middle button a second time will complete the wire and start a new one Click the right button to terminate wiring Chapter 4 Schematic Editor If you have a two button mouse you can start a wire by pressing F3 or double clicking the left button Single clicking the left button will complete the wire and start a new one Click the right button to terminate wiring Alternatively click the Wire button on the toolbar You can start a wire by single clicking the left button otherwise continue as described above Press the Wire button again to cancel this mode
338. n expression and will be evaluated Note that property substitutions are performed before expressions are evaluated so the result of an expression can depend on any combination of property values If the attempt to evaluate the expression fails the result will be empty No error message will be reported Keywords Any text enclosed by lt and gt represents a keyword The keyword along with the lt and gt will be substituted according to the keyword as defined in the following table There are two types of keyword simple and compound Simple keywords are just a single word whereas compound keywords consist of sequence of names and values separated by colons Compound keywords are used to generate multiple netlist lines for applications such as creating series and parallel combinations How Template Properties are Evaluated Template properties are processed in two passes In the first pass the property names enclosed by are substituted while keywords and expressions pass through untouched In the second pass keywords and expressions are processed and the character is treated literally This makes it possible to use property values in expressions and the control values for the multi line keywords For example SMODELSS REF lt nodelist gt VALUE L L W W AD W 0 5u if L lu W 0 5u MODEL M REF Q23 and VALUE N1 this would resolve to the following after the first pass MS Q23 lt nodelist gt N1 L
339. n of SIMetrix is available for Windows See above for system requirements The bit length of a processor e g 32 64 etc can mean many things but it usually refers to the size of the internal registers and thus the maximum range of addressable memory Up until recently all personal computers and workstations used 32 bit processors and so the maximum memory range was 232 or 4GBytes This is no longer the unimaginably large amount of memory that it once was In order to access more memory than this we need more than 32 bits and the usual choice is to increase it to 64 The memory range is the chief benefit of using a 64 bit processor and you should not expect substantial performance improvements With SIMetrix the main area where 4GBytes of memory may not be enough is graph plotting If you run simulations with ten million time points or more you should seriously consider using the 64 bit version of SIMetrix Note that all 64 bit applications require a 64 bit operating system as well as a 64 bit processor You cannot install or run the 64 bit version of SIMetrix on a 32 bit operating system even if the processor is 64bit Although major performance benefits should not be expected a 64 bit application will usually run faster with a 64 bit OS compared to a 32 bit version of the same application running with a 64 bit OS Chapter 2 Quick Start Chapter 2 Quick Start Tutorials Overview This chapter covers a number of tutorials that will hel
340. n terms of time voltage or time current pairs To place a PWL source select menu PlacelVoltage SourcesIPWL Source or PlacelCurrent SourcesIPWL Source To edit the device select it and press F7 or Edit Part popup menu This will open the Edit PWL Dialog which allows you to enter time and voltage current values As well as entering values individually you can also paste them from the Windows clipboard by pressing the Paste button or control V The values can be copied to the clipboard using a text editor The values may be separated by spaces tabs commas or new lines PWL sources may be used in both SIMetrix and SIMPLIS modes When defined in this way PWL sources are limited to 256 points In SIMetrix mode much larger PWL sources may be defined See the Analog Device Reference in the Simulator Reference Manual for more information In SIMPLIS mode a check box titled Source Idle during POP and AC analyses will also be shown This will be checked by default meaning that the source is inactive in POP and AC analyses Power Supply Fixed Current Source Select menu PlacelVoltage Sources Power Supply or PlacelCurrent SourcesIDC Source to place a fixed voltage or current source These devices work in both SIMetrix and SIMPLIS modes AC Source The small signal analysis modes AC sweep and Transfer Function require AC sources for their input stimulus To place an AC source select menu PlacelVoltage Sources AC Source for AC anal
341. n the status bar with or without the graph readings Editing Style or and Format of Cursor Dimension Double click on one of the displayed values of the cursor dimension The following dialog will open 257 User s Manual 258 J Edit Crosshair Dimension Px Properties Label Style Label 1 x1 F Show Absolute Show Difference Label 2 22 Automatic Intemal Label 3 xdi 5 Extemal Font items enclosed with are symbolic Edit Font values See help for details 7 Gee ee Edit values as described below Label The labels are the three values displayed on the dimension Label is the value displayed above the reference cursor label 2 is the value displayed above the main cursor and label 3 is the value displayed as the difference x1 x2 and xdiff are symbolic values that will be substituted with the absolute position of the reference cursor the absolute position of the main cursor and the difference between them respectively You can add additional text to these For example if you changed label 1 to Pulse Start x1 the value displayed for the position of the reference cursor would be prefixed with Pulse Start You can use expressions relating constants and symbolic values enclosed by Expressions must be enclosed in braces and For example the expression 1 xditf will cause the difference value to be displayed as a reciproca
342. n variable 379 UpdateCurvesNoFixSelected option variable 379 UseAltGraphPrintStyles option variable 379 UseGreekMu option variable 379 seNativeXpSplitters option variable 380 JSER CAT 170 UserCatalog option variable 380 UserScriptDir option variable 380 UserSymbolsDir option variable 380 UserSystemSymbolDir option variable 380 UseSmallGraphCursor option variable 380 V value property 95 156 valuescript property 96 vector function 330 VertTextMode option variable 381 VNTOL 199 Voltage CG 404 plotting 59 60 plotting differential 60 Voltage source controlled 137 fixed 137 sweeping 183 WwW WarnSubControls option variable 381 Window graph 221 schematic 62 symbol editor 83 WireWidth option variable 381 WorkingCatalog option variable 381 Worksheets schematic 72 X XatNthY function 295 XatNthYn function 296 XatNthYp function 296 XatNthYpct function 296 XFromY function 330 XY function 330 Y YatX 296 YatXpct 296 YFromX function 330 Z Zooming graph 268 Index 405
343. n wanted to alter the damping factor to 0 8 you only need to type in its new value Let alpha 0 8 then re run the simulator To execute the Let commands from within a script prefix the parameter names with global E g Let global f0 1k In many cases the PARAM approach is more convenient as the values can be stored with the schematic Example passing parameters to subcircuits If the filter example above was implemented as a subcircuit different values of the parameters freq alpha and C1 could be passed to each instance of the subcircuit This allows several filters with differing roll off frequencies and damping factors to be quickly drawn C1 C1 1 ZNE Pitted C1 alpha 2 2 PI iS C1 alpha Ri ip C1 alpha ae Wa IN E OUT Chapter 5 Components You can set the values of the parameters for each instance of the above subcircuit by appending the expressions to the value property of the symbol in the main circuit separated by a E g U Filter C1 10n alpha 1 freq 10k 161 User s Manual Chapter 6 Device Library and Parts Management Overview The electrical characteristics for semiconductor devices such as transistors and for more complex devices such as operational amplifiers are not built in to the simulator program but are defined in separate library files These are text files containing MODEL and SUBCKT controls Some libraries have been supplied with
344. native would be to measure the capacitance of an actual device Notes of Soft Recovery Diode Model The soft recovery diode does not use the standard SPICE model but a new model based on work at the University of Washington Full details of the model can be found in the Simulator Reference Manual Subcircuits Overview Subcircuits are a method of defining a circuit block which can be referenced any number of times by a single netlist line or schematic device Subcircuits are the method used to define many device models such as op amps It is also the underlying mechanism of the hierarchical schematic entry system 153 User s Manual You don t need to know anything about subcircuits unless you wish to define you own device models perhaps to build up a library of tested blocks for general distribution If you just wish to enter your circuit in a modular manner hierarchical schematic entry is probably the more appropriate method See Hierarchical Schematic Entry on page 72 for details This section explains how to create a subcircuit from a schematic and how to reference one in netlist or schematic For the SUBCKT control syntax see the Command Reference chapter of the Simulator Reference Manual Creating a Sub circuit from a Schematic Subcircuits must be defined in text form as a netlist However the schematic editor can be used to generate the netlist To create a sub circuit from a schematic you need to identify w
345. nd Data Analysis Expressions Graph object labels may contain expressions enclosed in curly braces These will be evaluated and the result of the evaluation replaces the complete expression and curly braces Any script function may be used although only a subset are applicable The function cv is particularly useful cv returns the data for a curve and you can use this with functions that return a scalar from a vector to attach measurements to curve markers or cursors Use curve as the argument for cv i e cv Scurves For example this will return the RMS value for the curve attached to a curve marker RMS1 cv ScurveS For crosshair dimension objects the cursor dimensions use curvel or Yocurve2 instead of Y curve The Truncate function is useful if you want to display a measurement applied to a range marked out by the cursors So the following example will return the RMS value of the curve attached to a curve marker between the range marked out by the cursors RMS1 Truncate cv Scurve Sgraph refcursor x1 sgraph maincursor x1 You can also use string functions For example graph title usually returns the pathname of the schematic This is not guaranteed but this will always be the case if the schematic has been saved and was run using the regular menus You can use the SplitPath function to obtain just the file name E g splitpath sGraph GroupTitle 2 You can use the above
346. neeeeeeeeees 222 Fixed Probes aee aM wen ae ieee 223 Fixed Probe Options csccesceeseeeeeeeseeeeneeeneesees 224 Fixed Bus Probe Options c ccsceeeeeeeeeeeteeeeeees 227 Using Fixed Probes in Hierarchical Designs 228 Adding Fixed Probes After a Run has Started 228 Changing Update Period and Start Delay 228 Random ProbeSivrcsiacdvecusteiee desi an Aedes einen ash 228 General Behaviul cccccccssceeeteeeesneeeesseeeeeteees 228 FUNCION Sii ea emit ae ee Arete Se 229 Notes on Probe Functions ccceeesseeeeseeeeeneeees 230 Plotting Noise Analysis Results eee 231 Plotting Transfer Function Analysis Results 231 Fourier AnalySiS eeesceessseeeseneeeesseeereneeeeenetereaes 232 Probing B S S S a ee e e a EE 236 Bus Probe Options ecceesceeeeeeeeeeeeeeteeeeeeeeeeeee 237 Plotting an Arbitrary Expression ssec 238 Curve Arithmetic cccccecceeeseeeeeeeeeeeseeeessneeeseeees 243 Using Random Probes in Hierarchical Designs 243 Plot Journals and Updating Curves sssesseseeeeeeeeeen 245 OVEWIOW 2th is ccs wa nears a a aoia 245 Update Curves rr 246 Plot JOUrMalSyciie tccinseitiesistee te hans eased aden ceeds 246 Graph Layout Multiple Y Axis Graphs eeeeeeeee 246 AUtOAXIS Feature eeeeeeeeeeeeneeeseneeeeeneeeeeeneetenaes 248 Manually Creating Axes and Grids ceeeeeee 249 Selecting AXES 2 2 2 c ie
347. nees 341 Basic Operationss cs 2 3 3 ie ei adie tinsen NEA 341 User s Manual Chapter 14 14 Using Verilog HDL in SlMetrix Schematics 342 Creating Schematic Symbols ccc 342 Editing Parameters ccsseeesseeesseeeeeneeeeeneeeeeaes 342 Module Cache sessista ienn a ho aie 343 OPSratiOn sit EEEE ATT 343 Simulation Options ecceeceeeeeeeeeeeneeeeeeeneeteeeeeeeeneees 343 Verilog Simulator eeceeceeeeeeeeeneeeeeeseeeeeneeeneeees 343 Timing Resolution eee eeeeeeeseeteneeeeeneeeeeeneeeeaeee 343 Open Console for Verilog Process 344 PUTO FAL ioe ers coves ete salen e enana ai A en eves 344 Proceduress 2 iene ial AR eg 345 Verilog Simulator Interface eeeceeeeeteeeeeeeeeeeeeees 349 VBI eccune aide E 349 Interface Configuration cceeeeeeeeeeeeeeeeeeneeee 350 LAUNCH Serpia ienien ee E 350 Verilog Simulation Preparation e cceeeeeees 350 Sundry Topics Saving and Restoring Sessions esseeeeeererereenen 351 OVENIOW sas e eaa a ean eaten 351 Saving a SESSION eee cece ceeeeeeeeeeeeeeeeeeeeeeeeeeeeeeaeens 351 Restoring a Session ccesceeeeeeeseeeseetseeeseeeseeeees 351 Where is Session Data Stored cece 351 Symbolic Path Names ee eee eee eter eee eeee 351 OVOIVIEW ciori iedreen nee eben 351 Definition aps go ue cei eek neh eee oe 352 Configuration File Example ccecceeeeeeeeees 353 Using Symbolic Names
348. nent which looks exactly like its linear counterpart The difference is that when you try and edit its value with F7 or menu Edit Part you will be prompted to enter an expression In the case of the resistor and capacitor this relates its value to the applied voltage and for inductor the expression relates its inductance to its current For resistors and capacitors the terminal voltage is referred in the equation as V N1 and for inductors the device s current is referred to as I V1 Creating Models Overview SIMetrix version 5 1 introduced a new soft recovery diode model for use in power electronics circuits As this model is not a SPICE standard there are no models available from device manufacturers or other sources So we therefore also developed a soft recovery diode parameter extractor that allows the creation of soft recovery diode models from data sheet values The parameter extraction tool works directly within the schematic environment and may be used in a similar manner to other parameterised devices such as the parameterised opamp However there is also an option to save a particular model to the device library and so making it available as a standard part Creating Soft Recovery Diode Models 1 Select menu PlacelCreate ModellSoft Recovery Diode You will see this dialog box 151 User s Manual 152 J Create Diode Model Se DC Forward bias spec d1 idi 1m a Vd2 700m a
349. ng the splitter bar between it and the schematic drawing area If you have SIMetrix SIMPLIS you should use the SIMULATOR control to mark SIMetrix and SIMPLIS entries If SIMULATOR SIMetrix is encountered all following lines will only work in SIMetrix mode and will be ignored by SIMPLIS Conversely any lines following SIMULATOR SIMPLIS will only be accepted by SIMPLIS and will be ignored by SIMetrix All lines before any occurrence of SIMULATOR or after SIMULATOR DEFAULT will be accepted by both simulators Running the Simulator SiMetrix To run simulator select the Simulator Run menu item press F9 or select the run button in the SimulatorlChoose Analysis dialog box A dialog box will show the status of the simulation You can pause the simulation by selecting the Pause button on the simulator status dialog box To restart select the Resume button the Pause button changes name when simulation pauses or the SimulatorlResume menu item There is no obligation to resume a simulation that has been paused If you start a new run after having paused the previous one you will be asked whether you wish to abandon the pending simulation run Notes 1 There is no need to specify in advance of the simulation what voltages currents and or powers you wish to look at By default everything except signals internal to some device models are stored in a disk file You can decide after the run is complete what you wish to look at 2 Itis recom
350. ngs are shown in the following table 383 User s Manual Option Name Possible Values Default in bold RebuildConfig true false BuildPreferenceSettings askmigrate true false BuildAssociations ask true false BuildModelLibs ifempty merge no BuildSymbolLibs ifempty merge no Description Auto configuration proceeds if this is set to true Auto configuration automatically sets this to false on completion Build user preference settings askmigrate ask the user whether he wants to migrate settings from an earlier version if available true Build default values false do nothing Build file associations Windows only ask ask the user if he wants file association to be performed true file associations performed unconditionally false file associations not performed Install system model libraries ifempty install libraries if there are no libraries currently installed merge merge system libraries with currently installed libraries no do not install system libraries Install system symbol libraries ifempty install libraries if there are no libraries currently installed merge merge system libraries with currently installed libraries no do not install system libraries The settings in the above table should be placed in the file in Options section in the form 384 Chapter 14 Sundry Topics Options name value For example Options BuildSymbolLibs merge Sk
351. nment Chapter 9 Graphs Probes and Data Analysis Graph Symbolic Values Most graph objects have one or more label properties that can be used to display text on the graph As well as literal text these label properties may also use symbolic values enclosed with These symbolic values return values of other properties belonging to the object For example curve marker objects have a property called X1 which is always set to the x location of the curve to which it is attached So X1 in a curve marker label will return the x location allowing it to be displayed on the graph The X1 property is updated every time the curve marker is moved the label value is reevaluated every time the graph is repainted Sometimes it is necessary to force a repaint to get labels with symbolic values or and expressions to update You can do this by moving another window over the graph or adjusting the size of the window slightly Some properties return the ID of another graph object For example the Curve property returns the ID of the curve to which it is attached These can be used to access properties of the referenced object This is done by appending with a followed by the referenced object s property name For example curve label returns the label property of the curve attached to the curve marker This indirect access to graph object properties can be nested to any level although there is probably no good reason for any more than two levels cur
352. nsmission Line Select from menu PlacelPassives Trans Line Lossy RLC Editing in the usual way will display J Resistance per unit length Inductance per unit length 250n 5 Capacitance per unit length 100p S Length 1 a Relative tolerance 1 8 Absolute tolerance 1 a Oe La Lossy lines must be defined in terms of their per unit length impedance characteristics Currently only series losses are supported Enter parameters as indicated The absolute tolerance and relative tolerance parameters control the accuracy speed trade off for the model Reduce these values for greater accuracy Fixed Voltage and Current Sources See Circuit Stimulus on page 46 Controlled Sources There are four types which can be found under menu PlacelControlled Sources Voltage controlled voltage source or VCVS Voltage controlled current source or VCCS Current controlled voltage source or CCVS Current controlled current source or CCCS 137 User s Manual 138 These have a variety of uses A VCVS can implement an ideal opamp current controlled devices can monitor current voltage controlled devices can convert a differential signal to single ended They require just one value to define them which is their gain Edit value in the usual way and you will be presented with a dialog similar to that used for resistors capacitors and inductors but without the Parameters button Voltage Controlled Switch This is essentiall
353. nternal base voltage of q1 not the base current The base current would be q1 b For the vector names output by a noise analysis refer to NOISE on page 225 of the Simulator Reference Manual Edit Filter Pressing the Edit Filter button opens E J Edit Available Vectors Subcircut filter Signal type Al 5 Voltages only cuit Currents only Wildcard fitter Use to match one or more characters Use to match a single character This allows you to select what is displayed in the available vectors dialog This is useful when simulating large circuits and the number of vectors is very large Sub circuit Filter All Vectors at all levels are displayed Top level Only vectors for the top level are displayed Select sub circuit All sub circuit references will be displayed in the list box Select one of these Only vectors local to that sub circuit will be displayed in Available Vector list Signal Type All List all signal types Voltages Only Only voltages will be listed Currents Only Only currents will be listed Digital Only Only digital vectors will be listed Chapter 9 Graphs Probes and Data Analysis Wildcard filter Enter a character string containing and or to filter vector names matches 1 or more occurrences of any character and matches any single character Some examples matches anything X1 matches any signal name that starts with the three letters
354. nts Minima real real string Returns array of all minimum turning 327 points Minimum real complex Returns the largest value ina given 327 range RMS1 real real real Finds RMS value of data 328 SumNoise real real real Integrates noise data to find total 329 noise in the specified range XFromy real real real Returns an array of X values at a 330 real given Y value YFromX real real real Returns an array of Y values at a 330 given X value User Defined Functions The following functions are defined using the user defined functions mechanism They are defined as scripts but behave like functions Name Description Page BPBW lt data db_down Band pass bandwidth 288 Bandwidth data db_ down Same as BPBW 288 CentreFreq data db_down Centre frequency 289 Duty data threshold Duty cycle of first pulse 289 Fall data start end Fall time 290 Frequency data threshold Average frequency 291 287 User s Manual Name Description Page GainMargin data Gain Margin phaselnstabilityPoint HPBW data db_down High pass bandwidth 291 LPBW data db_down Low pass bandwidth 292 Overshoot data start end Overshoot 293 PeakToPeak data start Peak to Peak 294 end Period data threshold Period of first cycle 294 PhaseMargin data Phase Margin phaselnstabilityPoint PulseWidth data threshold Pulse width of first cycle 294 Rise data start end Rise time 295 XatNthY da
355. nts and Voc for input voltages where xox may be any name starting with a letter A symbol will be automatically created with all specified inputs Use I out to read output current voltage output only Use Vioutp outn to read differential output voltage and Viout to read single ended output voltage Implementation Arbitrary source Compile to binary using Verilog A Offers more functions and higher performance for complex definitions Requires license with VX option Single ended voltage P Single ended current gt Differential voltage 5 Differential current La lea Help You may specify an equation that defines an output voltage or current in terms of any number of input voltages and currents Input voltages are specified in the form V a or V a b where a and b may be any arbitrary name of your choice Input currents are specified in the form I a On completion SIMetrix will generate a schematic symbol complete with the input voltages and or currents that you reference in the equation Unlike earlier versions there is no need to specify how many input voltages and currents you wish to use SIMetrix will automatically determine this from the equation As well as input voltage and currents you can also reference the output voltage or current in your equation A single ended output voltage is accessed using V out while a differential output voltage is accessed using V outp outn If you specify
356. o a list based run that selects parameter values from a list To set up a list run select the List radio button then press Define List Enter the values for the list using the dialog box The Group Curves check box controls how graphs are displayed If unchecked curves for each run will have their own legend and curve colour If checked curves will all have the same colour and share a single legend Setting Up a SIMPLIS Monte Carlo Analysis An Example To set up a Monte Carlo analysis you must first define component tolerances This is done by defining each value as an expression using one of the functions Gauss Unif or WC Here is another example Open the same example circuit as above then make the following changes 1 Select R3 press shift F7 then enter the value 100 GAUSS 0 05 2 Select C2 press shift F7 then enter the value 100u GAUSS 0 2 3 Delete the fixed probes on the V1 input and on R1 This is just to prevent too many unnecessary curves being plotted The above will give R3 a 5 tolerance and C2 a 20 tolerance with a 3 Sigma Gaussian distribution Now set up the Monte Carlo run 1 Select menu Simulator lSetup Multi step 2 In Sweep mode select Monte Carlo 3 Enter the desired number of steps in Number of steps To demonstrate the concepts 10 will be sufficient but usually a Monte Carlo run would be a minimum of around 30 steps 215 User s Manual 216 4 Press Run You shoul
357. o is to rerun the entire simulation If instead however you had set Start plotting data to 80mS but left Start saving data at 0 SIMPLIS will have saved the switching instance data and only the PSP process will be needed to create the final plot data SIMPLIS is smart and is able to detect when you run the same simulation as before but with only changes to data output required So if you rerun the simulation with Start plotting data set to zero SIMPLIS will only perform the PSP which is very much quicker than the whole simulation 207 User s Manual 208 Stop Plotting Data This is the time at which the process of creating plot data is stopped i e when the PSP operation see above completes Number of Plot Points The total number of points to be generated These will be evenly spaced within the start and stop times Advanced Pressing the Advanced button opens the following dialog r J Transient Advanced Options mesm ano EN F Enable snapshot output Snapshot interval Mamet i Average Topology Duration Minimum la Measurement window 128 2 Snapshot output SIMPLIS has the ability to save its internal state in order to allow a run to be repeated from a certain time point This allows a run to be continued from where it previously left off Similar to SIMetrix transient restart facility The internal saved states are known as snapshots SIMPLIS always saves a snapshot at the end of e
358. o that it is positioned between inn and vsp This is what you will now have 40 STEP 1 Select a suitable category for this part you cant find one press New Category and enter a new category of your choice STEP 2 Select a suitable symbol for this part Select a symbol from the drop down box or press Auto Create Symbol to create a new one ff selecting an existing symbol you must make sure that the pin order matches the model definition shown below Press Help for assistance ff you use Auto Create Symbol the pin order will not need to be changed Blectrical Model SXOA1000 Choose Category for SXOA1000 Unassigned E New Category z Auto Create Symbol Define Symbol for SXOA1000 Operational Amplifier 5 terminal Pin order EJ E3 inp inn vsp vsn Edit Pin Names From C Users jrw Documents SIMetrix Examples Tutorials Tutorial3 mod se se ant 22 Inverting input 22 Non inv input l l re I I2 D2_N VEE 100u Subckt SXOA1000 VINP VINN VOUT VCC Opamp 22 Negative supply I line 14 m Chapter 2 Quick Start 3 Press OK You will now find our op amp listed under the Op amps category in the parts browser Notes You will not always need to execute the above procedure to associate models and symbols even for subcircuit devices SIMetrix is supplied with a data base of over 30000 devices that are
359. obes only If selected only voltages and currents that are explicitly probed will be output Other Options Force New Analysis This tells SIMPLIS to ignore any state information that it may have stored and which could be used to speed up the run For example any stored snapshots see above will not be used if this is selected No Forced Output Data If checked SIMPLIS will not force a data point before and after every switching instant Under most circumstances this option should remain turned OFF For very long simulations that generate extremely large data sets the waveform viewer may be slow responding to user commands In such cases turning ON the NO_FORCED_DATA option will reduce the number of simulation data points displayed in the waveform viewer during each switching cycle For long simulations that involve many switching instants in one switching cycle this reduction can be significant Enabling this option in no way degrades the accuracy of the SIMPLIS solution but it can potentially reduce the fidelity of the displayed waveforms within each switching cycle Multi step and Monte Carlo Analyses Overview The SIMetrix environment provides a facility to run automatic multiple SIMPLIS analyses Two modes are available namely parameter step and Monte Carlo In parameter step mode the run is repeated while setting a parameter value at each step The parameter may be used within any expression to describe a device or model
360. of that symbol To restore instances properties follow the instructions below 1 Select the instances whose properties you wish to restore 2 Select popup menu Restore Properties 3 There are two options New Properties Only will only add new properties to the selected instances That is any property that is present on the symbol definition but not on the schematic instance of it will be added All other properties will remain intact All Properties will restore all properties to that of the symbol definition This includes deleting any instance properties that are not in the symbol definition In effect this will restore the symbol as if it had just been placed using the PlacelFrom Symbol Library menu Note that REF properties will be automatically annotated to make them unique This option must be used with care Don t use it unless you are very clear about what it will do This function will restore properties according to the local symbol definition stored in the schematic This won t necessarily be the same as the global definition in the symbol library For more information see How Symbols are Stored on page 115 Template Property Overview The template property provides a method of customising the netlist entry for a schematic component Normally a single line is created in the netlist for each schematic component except F and H devices which are defined by two lines The line is created according to the values of
361. oil You should see something like this S1 P V 0 20 40 60 80 100 120 140 160 180 200 Time mSecs 20mSecs div You will notice that at t 0 the voltage is between 4 and 5 volts suggesting that the switch is not fully turned on or off This is because the output of U2 starts in the unknown state The unknown state is translated to a high impedance which leaves the output in a near floating state To calculate the DC operating point SIMetrix takes the port values after the first Verilog event which is the state after executing the init block In the Verilog design the output is the port out but you will notice in pulse_relay v that out is not defined in the init block Modify the pulse_relay v to add an initial definition for the out port as follows initial begin count 0 out 0 end Rerun the simulation and notice the change in the result at the start of the simulation Internal Verilog Nodes Have a look at the connection between U1 clk and U2 in This connects two Verilog signals but does not connect to any analog component Because of this it is implemented within the Verilog simulator and does not interact with the analog simulator 347 Simulator Reference Manual Although the node is not connected to the analog simulator its data is sent to SIMetrix so that it can be plotted Try plotting this node now you will notice that you get a digital plot with no analog detail Although
362. olate the results using the Interp function see page 324 The FFT plotting menu items run a script which interpolate the data if it detects that the results are unevenly spaced Use of these menus does not require special consideration by the user Further information on FFTs can be found on page 232 Chapter 11 Command and Function Reference FIR real real real Vector to be filtered Filter coefficients Initial conditions Default all zero Performs Finite Impulse Response digital filtering on supplied vector This function performs the operation Yn Xn Co Xn 1 C1 Xn2 C2 Where x is the input vector argument 1 c is the coefficient vector argument 2 y is the result returned value The third argument provide the history of x i e X4 X etc as required The operation of this function and also the HR function is simple but its application can be the subject of several volumes Below is the simple case of a four sample rolling average In principle an almost unlimited range of FIR filtering operations may be performed using this function Any text on Digital Signal Processing will provide further details Users should note that using this function applied to raw transient analysis data will not produce meaningful results as the values are unevenly spaced If you apply this function to simulation data you must either specify that the simulator outputs at fixed intervals select the Output at
363. olbar editing 71 placement options 358 unselecting 65 in box 65 using for IC design 112 automatic area and perimeter calculation 114 window 62 worksheets adding and removing 72 zooming box 66 in 66 out 66 to fit 66 schematic_path property 96 SchematicEditMode option variable 376 401 User s Manual SchematicExtension option variable 382 SchematicMoveMode option variable 376 SchematicReadOnly option variable 376 SchemDoubleClickScript option variable 376 ScriptDir option variable 353 376 ScriptExtension option variable 382 Scripts 301 location 362 options 361 startup 387 Scrolling graph 268 scterm property 96 Selecting schematic components and wires 63 Sensitivity analysis 197 sep template property keyword 101 series template property keyword 103 Set command 315 Show command 315 sign function 329 SimDataGroupDelete option variable 377 SIMPLIS Analysis modes AC 212 Periodic operating point POP 209 211 transient 207 analysis modes 206 options 213 primitive components 130 using SPICE models 122 SIMPLISComponentButtons option variable 377 SIMPLISPath option variable 377 Simulation modes 42 Simulator controls manual entry 57 Simulator options 198 simulator property 96 SIMXIDX n 172 sin function 329 Singular matrix 45 SnapshotExtension option variable 382 Snapshots SIMPLIS 208 sqrt function 329 402 Index STARTPATH system path 352 Startup script 387 STARTUP INI 355 StartUpDir option variable 3
364. olerance Chapter 13 Verilog HDL Simulation Module Cache Operation Before starting a simulation and also when creating a symbol from a Verilog design SIMetrix needs to gather some information about each Verilog module used in the circuit It does this by starting a Verilog simulation then interrogating the Verilog simulator via VPI This process can take some time if there are many Verilog modules in the circuit To speed things up SIMetrix caches the information obtained for future use The cache mechanism calculates the MD5 checksum of the Verilog file and stores this with the cached information in the cache file When the cached information is required SIMetrix calculates the MD5 checksum of the Verilog file and looks to see whether there is a cache item with that MD5 value If there is it will use the cached data If not it will retrieve the information via the Verilog simulator For more information about the Module cache see the Simulator Reference Manual Chapter 4 Verilog HDL Interface VSXA Simulation Options There are three Verilog simulation options available through the user interface These can be accessed from the Choose Analysis dialog box as follows 1 Select menu Simulator Choose Analysis 2 Select the Options tab 3 See options under Verilog HDL Options Verilog Simulator This option allows you to select the Verilog simulator used for the main simulation With Windows version there will be
365. oltage Controlled Delay Implements a variable analog delay This device has three parameters as defined in the table below Double click the device to edit its parameters Chapter 5 Components Parameter Description Max delay The maximum delay that the device may provide in seconds Voltage for minimum Input voltage for minimum delay i e zero delay Voltage for maximum Input voltage for maximum delay The delay when delay between the minimun and maximum voltages will be calculated following a linear characteristic Fixed Delay Implements a fixed analog delay This device has just a single parameter defining its delay in seconds Double click the device to edit Sinewave VCO Implements a sinewave voltage controlled oscillator This has four parameters as defined below Parameter Description Amplitude Peak amplitude of sine wave Centre Frequency Frequency for zero volts input Gain Hz Volt Change in frequency for each volt change in the input Minimum steps per Minimum number of time points per cycle The cycle simulator will force time points to ensure that each cycle has at least the number specified Pulse Width Modulator Implements a voltage controlled pulse width Defined by 6 parameters as follows Parameter Description Frequency Frequency of pulse Input low voltage Voltage for zero duty cycle 14 User s Manual 144 Parameter Description Input high voltage Voltage for
366. omponent s value and other properties will always have a consistent location relative to the symbol body and there will be no confusion as to which component it belongs If you have a situation where some device label property text clashes with another your first thought will probably be to move the label We ask you instead to think about moving the component that owns the label it s nearly always a better way In situations where the label is very long it might be better to hide it altogether If you find that moving the label is the only way then you should be aware of how the positions of property text are defined In SIMetrix property positions can be defined in one of two ways namely Auto and Absolute Most of the standard symbols have their properties defined as Auto This means that SIMetrix chooses the location of the property on a specified edge of the symbol and ensures that it doesn t clash with other properties on the same edge Auto properties are always horizontal and therefore easily readable The position of Absolute properties is fixed relative to the symbol body regardless of the orientation of the symbol and location of other properties When the symbol is rotated through 90 degrees absolute text will also rotate Absolute properties are intended for situations where the precise location is important such as in a title block When a visible property on a symbol is moved by the method described above it and all other
367. on page 192 In the previous example we swept the tail current to find the optimum value to minimise noise for a 1K source resistance Here we extend the example further so that the run is repeated for a range of source resistances The source resistance is varied by performing a parameter step on sourceR Here is what the dialog settings are for the multi step run J Define Multi Step Analysis mE Sweep mode Step parameters Device Stat value 1k a Parameter Stop value 100k a Model parameter Steps per decade 10 S Temperature Decade E Group curves Fi Linear Monte Cario List Device name Cancel Parameter name sourceR Help This does a decade sweep varying sourceR from 1K to 100k with 2 steps per decade This is the result we get Chapter 7 Analysis Modes 10 sourceR 100040 sourceR 31622 7766017 1 sourceR 10000 z Z 100 gt 101 ourceR 3162 27766017 ole k i sourceR 1000 ip 10u 100 im 10m taili Example 2 The following circuit is a simple model of a full bridge switching amplifier used to deliver a controlled current into an inductance 250n L100n Joss 2 48 ce c1 vi n 2 22m R6 IRFP260 IRFP260 Gi ARF 1 1 2 2 a P ea RT x x R2 2 1m he E2 pa Sources V2 and V3 have been defined to be dependent on a parameter named duty which specifies the duty cycle of the switching waveform See EXAMPLES BRIDGE BRI
368. onstruct Verilog HDL Symbol 2 Navigate to the Verilog design file S Metrix expects the file extension v or vl Select the file then close 3 You should see an image of the symbol ready to place Place in the usual way 4 Tf there are errors in the Verilog file you will see a message in the form ERROR Cannot parse verilog design file filename For details see log file filename log Cannot parse Verilog HDL file No symbol created The log file should list details of the error This file is generated by the GPL Cver Verilog simulator and will contain additional information that can obscure the desired error message Verilog errors must be rectified before SIMetrix can create a symbol Editing Parameters The symbol creation feature described above builds the necessary functionality in the symbol to allow GUI editing of the device s parameters To use this just edit the schematic instance in the usual way by double clicking or selecting followed by F7 You will see a dialog box showing a number of parameters The first parameters starting with Voltage input logic zero threshold and ending with Threshold time tolerance along with the check boxes Disable output of non analog vectors and Disable Module Cache are built in parameters that are defined for all Verilog devices Any parameters defined within the Verilog definition will be shown in addition to these and listed after Threshold time t
369. ooth Rise 0 z Equal rise and fall e od Sine Fall 0 L ut nse and ta z Cosine Delay 0 B Use delay T Pulse Damping 0 a se phase F One pulse Vertical One pulse exp Initial 0 Offset 500m a Step Pulse 1 2 Amplitude 1 a E OF cy Select the wave shape on the right hand side then enter the parameters as appropriate The following notes provide details on some of the controls Damping describes an exponential decay factor for sinusoidal wave shapes The decay is governed by the expression e damping t 46 SIMPLIS is available with SIMetrix SIMPLIS products Chapter 3 Getting Started s Off until delay if checked specifies that the signal will be at the Initial value until the delay period has elapsed Note that some parameters can be specified in more than one way For example both frequency and period edit controls are supplied Changing one will cause the other to be updated appropriately The same applies to duty and width and the vertical controls in the lower half A Cosine wave shape combined with a positive delay and with Off until delay checked will only function correctly in SIMPLIS mode If in SIMPLIS simulation mode you will also see a check box titled Source Idle during POP and AC analyses If checked the source will be disabled in POP and AC analysis modes PWL Source This device can be used to describe a piece wise linear source A PWL source can describe any arbitrary wave shape i
370. or to the FFT computation Specify here the number of points and the order The number of points entry may be forced to a minimum if a high stop frequency is specified in the Frequency Display section The number of interpolation points required depends on the highest significant frequency component in the signal being analysed If you have an idea what this is a useful trick to set the number of points to a suitable value is to increase the stop frequency value in the Frequency Display section up to that frequency This will automatically set the number of interpolation points to the required value to handle that frequency If you don t actually want to display frequencies up to that level you can bring the stop frequency back down again The number of interpolation points will stay at the value reached If in doubt plot the FFT twice using a different number of points If the two results are significantly different in the frequency band of interest then you should increase the number of points further Usually an interpolation order of 2 is a suitable value but you should reduce this to 1 if analysing signals with abrupt edges If analysing a smooth signal such as a sinusoid useful improvements can be gained by increasing the order to 3 Advanced Options Pressing the Advanced Options button will open this dialog box 235 User s Manual 236 f J Advanced Fourier Data span Window Rectangular Specify Hanning St
371. ose menu EditlCopy In second schematic choose EditlPaste To Delete Select items as described above then click the Cut toolbar button or press the delete key Multiple Selection Individual items which do not lie within a single rectangle can be selected by holding down the control key while using the mouse to select the desired items as described above Selecting Wires Only Hold down shift key while performing select operation Holding Down the ALT Key While selecting will limit component selection to only devices that are wholly enclosed by the selection box Unselecting Place the cursor in an empty area and press left mouse key Unselect Items Within a Rectangle You can unselect an area of schematic enclosed by the selection box Use menu EditlUnselectlRectangle 65 User s Manual 66 To Change a Component Reference Select component s then press F8 or select schematic menu EditIChange Reference Enter new reference To Correct a Mistake Click the Undo toolbar button By default you can backtrack up to ten operations but this can be changed with FilelOptions General If you want to undo the undo operation select the menu EditIRedo menu item To Add Text To a Schematic Select the popup menu item EditlAdd Free Text This opens a dialog box prompting you for the text to be entered After entering text and closing box you can then position the text where you require using the mouse To
372. otation Display Precision 279 Bias Annotation and Long Transient Runs 279 SAVING Data nsee a a e as 279 Saving the Data of a Simulation c ceee 279 Restoring Simulation Data ccceseeeeeseeeeeees 280 Performance Analysis and HistogramS seee 280 OVEIVICW fet einen Sheena hick tease edie 280 Examples ae eee ea aes 281 Histograms kiasan nieve eee 283 Goal FUNCIONS vrisne Erni 286 Data Import and Export eeceeeseeeeeseeeeeeneeteeneeereneees 296 Importing SPICE3 Raw and CSDF Files 296 Importing Tabulated ASCII Data eerie 297 Exporting SPICES Raw FileS ccceseeeeeeeeeee 297 Exporting Datta s eiit naan 297 Launching Other Applications cceeeeeees 298 Data Files Text Format 298 Chapter 10 The Command Shell Command Line sesoses n 300 Command HiStory eeceeecessceeeeeeeeeeeeneeseeeeeeeeees 300 Message WINdOW eeeeesseeeeeneeeeeneeeeeneeeeeneeeee 300 Multiple commands on one line eee 301 SGMptSes gio teks ected es ele a es eet ed 301 Command Line Editing cceeceeeeeeeeeeeeeeeeeeeees 301 Command Line Switches ecceeceeeteeeeeeneteees 301 Editing the Menu SyStem ecceeeeseeeeeeeeseeeeeeeeeeeeeaes 301 OAT A EE EEE tts Seen cele 301 Procedures enyana e a 302 User Defined Toolbars and Buttons 303 Message WINdOW s ssssssriierierernenaciereirentirunrirerrirareienne 303 Menu Reference
373. otation markers Auto save interval minutes 357 User s Manual 358 Enter a value to enable schematic auto save SIMetrix will automatically save a backup copy of your schemnatic at the interval specified If SIMetrix aborts abnormally perhaps due to a power failure you will be prompted to recover the auto saved schematic when you next start SIMetrix Hierarchy Highlightling Double click mode Edit Mode Property Editing Placement Wiring Grid Initial Simulator Graph Printing Axis line width Grid line width Minor grid Curve line width Curve identification Check the Disabled box to disable highlighting through the hierarchy With deep and complex hierarchies net highlightling can be time consuming Checking this box will restrict highlighting to the current schematic only Selects action when double clicking a schematic instance Select Classic to retain pre version 5 0 behaviour whereby double clicking always starts a new wire Select Edit selected component for the default behaviour which is to invoke the device value editor Controls how wires are treated during move operations See Edit Modes on page 69 for full details Enable GUI Property Edits If checked allows property text i e labels to be moved using mouse actions Labels themselves can be editted by double clicking See Notes on Property Text Position on page 67 before checking this option When to auto repeat placement
374. ote that only compatible symbols that have the same number of pins as the selected device will be shown If an appropriate symbol is not available you instruct SIMetrix to create one for you by pressing the Auto Create Symbol button The symbol created will be functionally correct but of course its design and labelling may not be exactly what you would like You can edit the pin names of the new symbol by Chapter 6 Device Library and Parts Management pressing Edit Pin Names If other changes are required you can edit the symbol using the graphical symbol editor at a later time The next list box allows the pin order to be changed If you used the auto create symbol described in the above paragraph you will not need to change the pin order Even if you used an existing symbol from the drop down box you probably won t need to change the default as most devices such as opamps and MOSFETs use a de facto standard pin order Usually you can check the pin order from the Electrical Model display at the bottom of the dialog box Many subcircuit definitions are preceded by text which identifies each connection to the sub circuit This must correspond exactly to the pin order of the symbol The names of symbol pins and the names used for the subcircuit terminations do not need to match only the order is important If the pin order does not match you can change it using the up and down arrow buttons Simply select a pin in the list box then move it up or d
375. ou will also find it under Recently Added Models To reduce the number of devices displayed to a manageable level you can specify a filter You can use the wild cards and here will match 1 or more of any character while will match any single character So on its own will match any string and so all devices will be displayed But IRF will display any device that starts with the three letters IRF IRF will display any device beginning with IRF and followed by three and only three characters 119 User s Manual 120 Selecting a Model by Specification For some classes of part you can select a model based on a desired specification For example if you are looking for an n channel power FET with a 200V max Vds and Rds on less than 0 5Ohms you can enter this specification and obtain a list of parts that meet it Currently devices supported for this scheme include power FETs diodes and Zener diodes This feature is available in both SIMetrix and SIMPLIS modes To use this method of selecting a device proceed as follows 1 Select one of the menus listed under Place Select by Specification The picture below show what you would see if selecting NMOS Power FET re J Select FET Part Number ld Vdsmax Rds on Vgs i 2N6782 35 100 06 2N7000 0 2 60 5 E 2N7000 0 28 60 5 2N7000 NXP 0 28 60 5 2N7000 PS 0 28 60 5 2N7000P 0 28 60 5 2N7002 0 115 60 3 75 2N7002 NXP 0 115 60 3
376. our then select item Text Box Edit colour as required Font Select button Edit Font to change font To change the default font select command shell menu Filel Options Font then select item Legend Box Edit font as required Text Box Placing Select menu AnnotatelText Box Enter required text then Ok You can use the symbolic constants date Y time and Y version to represent creation date creation time and the product version respectively Moving Place cursor inside the box and drag to new location Editing Properties Double click on the box or select then menu AnnotatelEdit Selected Object A dialog like the one shown for legend boxes see above will be displayed Note when editing the label you can use the symbolic constants as detailed in Placing above Caption and Free Text The Caption and Free Text objects are essentially the same the only difference is their initial font size and position Placing Select menu AnnotatelCaption or AnnotatelFree Text Enter required text then Ok You can use the symbolic constants date time and Yoversion to represent creation date creation time and the product version respectively Moving Place cursor inside the box and drag to new location Editing Properties Double click on the box or select then menu AnnotatelEdit Selected Object This will open a dialog similar to the one shown for curve markers but without the Automatic option for text alig
377. overy Diode Specification The parameter extractor allows the specification of three important characteristics of the diode These are the DC forward bias voltage reverse recovery and capacitance Currently reverse leakage and breakdown characteristics are not modelled To specify the forward bias characteristics simply enter the coordinates of two points on the graph showing forward drop versus diode current which is found in most data sheets You should choose values at the extremes The low current value will essentially determine the value of the IS parameter while the high current value defines the series resistance of the device The reverse recovery characteristics are explained in the following diagram Chapter 5 Components Tr dif dt IRM 37 E The values quoted in data sheets vary between manufacturers The value given for Tr is sometimes taken from the reverse peak rather than the zero crossing If this is the case you can calculate the time from the zero crossing to the reverse peak using the values for IRM and dIf dt and so arrive at the value of Tr as shown above Some data sheets do not give the value of IRM In these cases the best that can be done is to enter an intelligent guess Capacitance is the measured value at zero bias Unfortunately this is not always quoted in data sheets in which case you can either enter zero which may speed simulation times or enter an estimated value Of course an alter
378. own the list Note that the change will only apply to the device s you are currently editing other devices associated with the same symbol will be unaffected Once you have finished selecting the category symbol and pin mapping you must select the Apply Changes button Your edits will be lost if you don t but you will be warned about this before closing the box Embedded Association It is possible to embed association information within the model file itself This is useful if you wish to prepare a model to distribute to other users and wish to spare them the burden of performing the association process themselves Models with embedded association can be installed by dropping their files in the command shell with no other action being required Only subcircuit devices may receive embedded association information The information is placed in a specially formatted comment line after the SUBCKT line but before the first device or command The line is in the form ASSOC Category category Symbol symbol Mapping mapping category Category for part If it has spaces this must be enclosed in double quotation marks symbol Internal symbol name to be used for part mapping Mapping information This changes the mapping between the subcircuit terminals and the symbol pin order Usually its easiest simply to arrange the subcircuit pin order to match the symbol pin order in which case this is not required If however there is some reason why rea
379. p you get started with SIMetrix Tutorial 1 is designed for total novices You may wish to skip to tutorial 2 if you already have experience with SPICE type programs Tutorial 2 assumes you have grasped the basics of using the schematic editor You don t have to worry about setting up analyses or the characteristics of any input stimulus such as V2 in tutorial 1 these procedures will be explained If you are an experienced circuit designer but have never used a circuit simulator before we recommend you read Simulation for the Novice below This will familiarise you with a few concepts about simulation that may be alien to you if you are used to traditional methods of evaluating circuits Examples and Tutorials Where are They In Linux the examples and tutorials reside in the examples tar file that forms part of the standard distribution Note that this file is not automatically installed On Windows the example files are first installed under the main installation root e g under C Program Files SIMetrix600 support examples but it is not intended that they are used from that location Instead they will be copied to your My Documents folder when SIMetrix starts for the first time but only if you accept the option to do so If you can t find the examples files you may need to manually copy them from the installation root to a suitable location of your choice In the following tutorial discussions the examples directory is
380. pecified model Suppose that you are using a BJT model that has a Vcb limit of 15V While you could place a differential voltage watch device across each instance of this model this would be time consuming and error prone Instead you can define a single SETSOA control that refers to the model name of the device The simulator will then automatically set up the limit test for every instance of that model You would usually enter a SETSOA control in the schematic editor s F11 window See Manual Entry of Simulator Commands on page 57 for details Refer to the Simulator Reference Manual command chapter for details about SETSOA It is also possible to set up an SOA specification for a model within the MODEL control Again see the Simulator Reference Manual for details 205 User s Manual Chapter 8 SIMPLIS Analysis Modes Overview 206 The SIMPLIS simulator is supplied with the SIMetrix SIMPLIS product For information on SIMPLIS see What is SIMPLIS on page 17 In this chapter we explain the analysis modes available with the SIMPLIS simulator There is more information on SIMPLIS analysis modes including full details of the netlist commands required to invoke them in the SIMPLIS Reference Manual To setup a SIMPLIS simulation you must first set the schematic editor to SIMPLIS mode See Simulation Modes SIMetrix or SIMPLIS on page 42 for details To set up a SIMPLIS analysis select menu SimulatorlChoose Anal
381. pectively For more information see the Command Reference chapter of the Simulator Reference Manual 231 User s Manual 232 Fourier Analysis A Fourier spectrum of a signal can be obtained in a number of ways You have a choice of using the default settings for the calculation of the Fourier spectrum or you can customise the settings for each plot The following menus use the default settings ProbelFourier Probe Voltage Quick ProbelMore Probe Functions Graph menu PlotIPlot Fourier of Curve Graph menu PlotlPlot Fourier of Curve Cursor span The following prompt you to customise the settings ProbelFourier Probe Voltage Custom ProbelFourierl Arbitrary Command shell menu Graphs and DatalFourier Default Settings The default fourier spectrum settings are Setting Default value Method Interpolated FFT Number of points Next integral power of two larger than number of points in signal Interpolation order 2 Span All data except Plot Plot Fourier of Curve Cursor span which uses cursor span Custom Settings With menu ProbelFourierlProbe Voltage Custom you will see the dialog below With the menus ProbelFourierlArbitrary or command shell menu Graphs and DatalFourier a dialog box similar to that shown in Plotting an Arbitrary Expression on page 238 will be displayed but will include a Fourier tab Click on the this tab to display the Fourier analysis options as shown below
382. pen circuit Enable For Analysis Decade 1n A ES Initial voltage Op E12 z ansie Resut i tala Cancel l Parameters You can type the new value in directly in the Result box or you can select a value using the mouse alone with the up and down arrow buttons Leave the Initial Condition setting at its default Open Circuit 2 Now re run the simulation This is the result you should see With R6 anp C1 added Amplifier Output mV 0 50 100 150 200 250 300 350 400 Time nSecs 50nSecs div The blue curve is the latest result This is now a big improvement on our first attempt You will notice that a new curve is displayed each time you run a new simulation This is the default behaviour but this can be changed so that for example old curves are deleted leaving only the latest on view To do this double click the probe that is the 29 User s Manual object labelled Amplifier Output Set Peristence to 1 and close the box For more infromation see Probe Options Sheet on page 225 We will now round off tutorial 1 by introducing AC analysis AC analysis performs a frequency sweep over a specified frequency range To set one up follow these instructions 1 In the schematic window select the menu SimulatorlChoose Analysis This is what you will see Fa
383. perty name Function netname scterm tol lot match schematic_path mapping params template valuescript incscript decscript handle simulator If this property is present on a symbol all nets connected to any of its pins will be named according to the value property The netname property is used by the Terminal component in the Symbols menu The Terminal component forces the net to which it is attached to have a user specified name The value of the netname property will be used in the absence of a value property Identifies the component as a Module Port These identify connections in hierarchical blocks These are used for Monte Carlo analysis to specify tolerances See page Path of schematic in hierarchical designs Rearranges pin order This is a sequence of numbers each representing a symbol pin order The order of the numbers in the mapping is the order in which the schematic symbol pins placed on the netlist For example the LMC6762B comparator in the library is assigned a mapping of 1 2 5 3 4 The output on the comparator symbol is pin 5 but the model requires this to be the third node in the netlist entry Additional parameters for device appended to value If model property is X the keyword params prefixes the params property value Specifies a customised netlist entry for the device See Template Property on page 96 below for full details Specifies a script to be called when F7 or
384. plemented by built in script uf_frequency Source may be obtained from the install CD see Install CD on page 16 GainMargin GainMargin data phaselInstabilityPoint Finds the gain margin in dB of data where data is the complex open loop transfer function of a closed loop system The gain margin is defined as the factor by which the open loop gain of a system must increase in order to become unstable phaselnstabilityPoint is the phase at which the system becomes unstable This is used to allow support for inverting and non inverting systems If data represents an inverting system phaselnstabilityPoint should be zero If data represents a non inverting system phaselnstabilityPoint should be 180 The function detects the frequencies at which the phase of the system is equal to phaselnstabilityPoint It then calculates the gain at those frequencies and returns the value that is numerically the smallest This might be negative indicating that the system is probably already unstable but could be conditionally stable If the phase of the system does not cross the phaselnstabilityPoint then no gain margin can be evaluated and the function will return an empty vector HPBW HPBW lt data db_down Finds high pass bandwidth 291 User s Manual 292 Y max db_down Returns the value of X1 as shown in the above diagram Y max is the y value at the maximum point X max is the x value at the maximum point X1 i
385. priate pin name with the same characters as required in the netlist E g to start a vector connection at a pin named IN1 enter the pin name IN1 To close a vector connection at pin IN3 use pin name IN3 Similarly to change a connection whose default type is v i e a single ended voltage to a differential current type id prefix the first pin name with id and a space E g pin name VIN would become id VIN Examples of the use of vector connections in symbols can be found with any of the digital gate symbols Defining Properties Properties define the behaviour of the symbol For full documentation on the use of properties see section Properties on page 94 In this section the methods of adding and editing properties in the symbol editor are described Adding a Single Property To add a property to a symbol select Property PinlAdd Property You will see the following dialog box 87 User s Manual 88 Name Value Text Location Property Attributes Ato Font style Default Normal Left Allows symbol to be selected by x z Pineda clicking in property text fptated Protected Inhibits editing of property Absolute are values on schematic Justification Left Top HE Linear Font scales linearty with zoom Cannot use with default font Property text will be oa hidden on schematic ll b E Show name Display name as well as value Resolve Enable resolution of exp
386. pt source A physical CD is only shipped to customers who purchase a portable license but the full CD content may also be accessed from our web site There is a web browseable version as well as a downloadable ISO file allowing you to burn your own CD The CD content may be found at our web site by navigating to http www simetrix co uk app product installation htm From there you should be able to find the download links page for the version of interest Be aware that a username and password is required to access the download links pages If you have current maintenance you can obtain these by registering at http www simetrix co uk app register htm Otherwise contact support simetrix co uk What Is Simetrix 16 SIMetrix is a mixed signal circuit simulator designed for ease and speed of use The core algorithms employed by the SIMetrix analog simulator are based on the SPICE program developed by the CAD IC group at the department of Electrical Engineering and Computer Sciences University of California at Berkeley The digital event driven simulator is derived from XSPICE developed by the Computer Science and Information Technology Laboratory Georgia Tech Research Institute Georgia Institute of Technology Although originally derived from these programs only about 30 of the overall application code can be traced to them A large part of the simulator code is either new or has been rewritten in order to provide new analysis features
387. pter 10 Statements Relating to POP Analysis sub heading Behaviour of POP Analysis after POP Convergence Failure Use default transient runtime Specify Run time after failed POP See above AC Analysis 212 AC is a small signal frequency domain analysis mode applied to a switching circuit Please refer to the SIMPLIS Reference Manual for full details of this analysis mode Note that AC analysis requires a POP analysis see above to be also defined Setting up an AC Analysis 1 Select menu SimulatorlChoose Analysis 2 Select AC check box on the right Note that the POP check box is automatically checked when AC is checked 3 Select AC tab at the top Periodic Operating Point Transient Sweep parameters Start frequency 1k a Decade Stop frequency 1Meg a Lngar Points per E decade 25 2 Enter parameters as described in the following sections AC Sweep Parameters Start frequency Enter the start frequency for the AC sweep Stop frequency Enter the stop frequency for the AC sweep Points per decade Number of points If a decade sweep is selected enter the number of points required for each decade If a linear sweep is selected enter the total number of points for the analysis Decade Linear Select type of sweep Chapter 8 SIMPLIS Analysis Modes SIMPLIS Options Save options All If selected all voltages and currents will be saved Voltages only If selected only node voltages will be saved Pr
388. r In situations where more than one instance is connected to the pin index may be used to specify which one index may have a value between 0 and 1 less than the number of devices connected Use lt join_num gt to determine how many devices are connected Note that the pin of the device must be directly connected i e with pins superimposed and not by wires lt JOIN gt is intended to be used for current probes JOIN_REF lt JOIN_REF gt Similar to lt JOIN REF gt except that instead of the literal REF property it returns how the connected instance is identified in the netlist This takes account of any TEMPLATE property the connected instance posesses or the MODEL property prefix if it does not have a TEMPLATE property JOIN_NUM lt JOIN_NUM gt Only valid for single pin instances Returns number of joined devices See lt JOIN gt above for details 105 User s Manual 106 JOIN_PIN lt JOIN_PIN index gt Only valid for single pin instances Returns connected pin name for another device connected to this device s only pin This can be used in conjunction with lt JOIN gt to return the current vector for a component E g lt JOIN REF gt lt JOIN_PIN gt for the probe device in would return R1 p In situations where more than one instance is connected to the pin index may be used to specify which one index may have a value between 0 and 1 less than the number of devices connected Use lt join_num gt
389. r Monte Carlo analysis two pieces of information are required Firstly the components that are matched to each other must be identified and secondly their matching tolerances need to be specified To Identify Matched Devices Select the components you wish to match to each other Use control key to select multiple components Select menu item Monte CarlolMatch Selected Devices You must now supply a lot name which must be unique You can use any alphanumeric name Matching Tolerances To specify device match tolerances proceed as follows Select the components you wish to match to each other Use control key to select multiple components Select menu item Monte CarlolSet Match Tolerances Enter the desired tolerance 335 User s Manual If using device tolerance parameters note that any absolute tolerance specified must be the same for all devices within the same lot Any devices with the same lot name but different absolute tolerance will be treated as belonging to a different lot For example if a circuit has four resistors all with lot name RN1 but two of them have an absolute tolerance of 1 and the other two have an absolute tolerance of 2 the 1 resistors won t be matched to the 2 resistors The 1 resistors will however be matched to each other as will the 2 resistors This does not apply to match tolerances It s perfectly OK to have devices with different match tolerances within the same lot Rando
390. r No 141 VCO No 142 Device Page Non linear transfer function 146 Laplace transfer function 148 Non linear resistor 151 Non linear capacitor 151 Non linear inductor 151 Analog Digital converter 144 Digital Analog converter 144 Digital counter 145 Digital shift register 145 NAND NOR OR AND gates 145 Digital bus register 145 129 User s Manual 130 SIMPLIS Primitive Components The following components are only available with the SIMetrix SIMPLIS product and when in SIMPLIS They can all be found under the menu PlacelSIMPLIS Primitives For full details see the SIMPLIS Reference Manual Device Comparator Set reset flip flop Set reset flip flop clocked J K flip flop D type flip flop Toggle flip flop Latch Simple switch voltage controlled Simple switch current controlled Transistor switch voltage controlled Transistor switch current controlled VPWL Resistor IPWL Resistor PWL Capacitor PWL Inductor Saturable Inductors and Transformers SIMetrix is supplied with a number of models for inductors and transformers that correctly model saturation and for most models hysteresis As these components are nearly always custom designed there is no catalog of manufacturers parts as there is with semiconductor devices Consequently a little more information is needed to specify one of these devices This section describes the facilities available and a description of the models available Core
391. raph 254 259 see also Graph cursors CurvePrintWidth option variable 367 CurveWeight option variable 367 D DataExtension option variable 382 DataGroupDelete 367 dB function 320 plotting 61 223 229 DC sweep analysis 186 decscript property 96 DefaultLib option variable 353 DefaultLib options variable 367 Defining keys 390 DefKey command 309 Defining menus DefMenu command 311 DefKey command 309 Deleting schematic wires 64 DevConfigFile options variable 368 Device power probing 230 diff function 320 Differential voltage probing 61 DigAxisHeight option variable 368 Digital analog converter 144 Disconnecting schematic wires 44 64 DisplaySimProgressMessage option variable 368 Distortion calculating 266 DOCSPATH system path 352 Duplicate models 172 Duty function 289 E EchoOn option variable 368 Editor option variable 368 EXEPATH system path 352 exp function 320 Exporting data 297 ExportRawFormat 369 Expressions 159 Extensions file 362 F Fall function 290 Fall time calculating 266 Fast start for transient analysis 178 ferrite 130 FFT function 320 of selected curve 268 phase 234 plotting 233 File extensions 362 Filter response functions 150 FIR function 321 Flipping schematic components 43 64 Floor function 321 Fonts customising 385 Index 391 User s Manual Fourier analysis 232 236 Frequency function 291 sweeping 185 with multi step analysis 202 Functional modelling arbitrary non
392. red it is restored to its default value A complete listing of available options with possible values is given below Note that option settings are persistent This means that their values are stored either in the INI file or in the system registry see Configuration Settings on page 355 and automatically restored at the start of each subsequent SIMetrix session List of Options Upper and lower case letters have been used for the option names in the following listing only for clarity Option names and their values are not in fact case sensitive Many of the options described below are supported by the Options dialog box in which case they are noted accordingly Unsupported Options Some options in the following list are marked as unsupported This means that they may be withdrawn in the future or their functionality changed 363 User s Manual 364 Name Type User interface support Description 700Extensions Boolean ActionOnMissingModel string AlwaysUseMarkers Boolean AnnoMinSuffix Numeric AutoStartWire Boolean AutoWireEnabled Boolean AWAllowRouteThruConnected Boolean Schematic symbols for the 700 series semi custom arrays are enabled if this is set Default AutoAssociate Action to be performed when attempting to place a model from the library but that model has not been associated If set to AutoAssociate will attempt to auto associate by simulating the model Graphs are printe
393. rence cursor can be moved in a left right mode using the right mouse button A Both cursors can be moved together using the left button while holding down the shift key Moving Cursors along a Curve You can move a cursor to a peak or trough using the hot key defined in the following table Key Function F5 Move main cursor to next peak shift F5 Move main cursor to previous peak F6 Move main cursor to next trough shift F6 Move main cursor to previous trough F7 Move reference cursor to next peak shift F7 Move reference cursor to previous peak F8 Move reference cursor to next trough shift F8 Move reference cursor to previous trough These operations can also be accessed from the graph menu Cursors Move Hiding Cursors You can temporarily hide all or some of the displayed cursors Menu Cursors Hide Show All has a toggle action and will hide all cursors if all cursors are currently displayed and vice versa If some cursors are visible and some are hidden you will be presented with an option to hide all cursors or show all cursors Menu Cursors Hide Show Select allows you to selectively hide or show some cursors Freezing Cursors You can freeze the cursors so that they can t be moved accidentally Select menu CursorslFreeze Unfreeze Chapter 9 Graphs Probes and Data Analysis Aligning Cursors Select menu CursorslAlign to align the two cursors so that they have the same y position Additional Cursors SIM
394. ression symbolic and special symbols Vertical a see This box allows you to define the name value and attributes of the property Note that if the property is not protected the value and attributes can be changed after the symbol has been placed on a schematic using the schematic popup Edit Properties Name Name of property This would usually be one of the special properties documented in Properties on page 94 You can however add any property name you wish to display as text or to provide a special function that you define in a custom script The only restriction is that the name must not contain spaces Value The property s value Don t confuse this with the Value property You can insert a new line by pressing the ENTER key But be careful that if you press the ENTER key accidentally intending to close the dialog that you must delete the erroneously entered new line Text location Define the position of the property s value text on the schematic Auto Absolute When auto is selected the property s value text is positioned automatically outside the symbol s border according to the options specified in Normal and Rotated When absolute is Normal Rotated Justification Hidden Vertical Chapter 4 Schematic Editor selected the property is placed at a fixed position relative to the symbol body You can define the location interactively with the mouse When auto is selected the
395. ridHeight option variable 371 minidx function 327 Minima function 327 Minimum function 327 MinorGridPrintWidth option variable 372 Mirroring schematic components 43 64 Model libraries LIB 171 associating models with symbols 167 diagnostics 172 duplicates 172 importing to schematic 171 indexes 172 installing 37 163 removing 167 SPICE to SIMPLIS conversion 122 model property 95 156 ModelExtension option variable 382 Module port 74 Monte Carlo analysis 332 analysing results 338 distributions 336 example 332 plotting single curve 338 running 336 setting seed 199 337 sweep 185 336 tolerance device 334 matching 335 model 335 Moving schematic components 64 MRUSize option variable 372 Multiple schematic placement 72 N Navigating hierarchical designs 74 netname property 96 Nets 395 User s Manual global 76 NewModelLifetime option variable 372 node template property keyword 100 nodelist template property keyword 100 nodename template property keyword 101 NoEditPinNamesWarning option variable 372 NolnitXaxisLimits option variable 372 Noise analysis 189 plotting results 231 real time 193 NoKeys option variable 373 NoMenu option variable 373 norm function 327 NoStopOnEnrror option variable 373 NoStopOnUnknownParam option variable 373 Nyquist plots 229 O OldUserCatalog option variable 374 OmitAsciiRevision option variable 374 OpenGroup command 313 Operating point analysis 181 viewing results 278 Op
396. rity of operations with SIMetrix can be executed from menus or pre defined keys and do not require the use of the command line However a few more advanced operations do require the use of the command line From the command line you can run a script or an internal command You can also define a new menu to call a script command or series of commands In fact all the built in menu and keys are in fact themselves defined as commands or scripts These definitions can be changed as well as new ones defined See Editing the Menu System on page 301 Details of some of the available commands are given in Command and Function Reference on page 308 The remainder are documented in the SIMetrix Script Reference Manual Command History A history of manually entered commands is available from the drop down list select arrow to the right of the command line Some other commands entered via menus or from a script may also be placed in the command history Message Window Various messages may be displayed in the message window below the command line These include command progress errors warnings and listing outputs The text in the window may be copied to the clipboard using a context sensitive menu activated by the right mouse button Chapter 10 The Command Shell Multiple commands on one line You can place multiple commands on the same line separated by a semi colon This is the only way a menu or key can be defined to exe
397. rmat as ALL CAT in the root folder ALL CAT is never modified Also another file is updated called OUT CAT This is the file used by the parts browser The process of building OUT CAT may take a few seconds if the model library is large Importing Models to a Schematic SIMetrix provides a means to automatically import all models needed for a schematic into that schematic The models are placed in the simulator command window opened with F11 see Manual Entry of Simulator Commands on page 57 Once the models are imported to a schematic it will no longer be necessary for SIMetrix to locate the models in the library when a simulation is run This has the following benefits It makes the schematic completely self contained This is useful for archiving or if you wish to pass the schematic to a third party You can edit the models locally without affecting the global library To import models to a schematic select the schematic menu SimulatorlImport Models You will be provided with two options Import Direct Copy and Import by Reference The first will import the model text directly into the schematic The second will put the model text into a file This will be referenced in the schematic s simulator command window using a INC control See Command Reference chapter of the Simulator Reference Manual Sundry Topics LIB Control The LIB netlist control allows the local specification of model library for a particular circu
398. robes and Data Analysis The following box should be displayed j1 J Edit Probe fae l Measurement Cursor Span AC Coupled Per Cycle Display on Schemat Add Measurement RMS x No x No No No x Remove Measurement To begin with a single measurment is shown Using the drop down box in the Measurment column select the desired measurement type You may also change some of the attributes Cursor Span specifies that the measurement will be calculated over the current cursor range If cursors are not switched on this will be ignored AC coupled specifies that the data will have its DC component removed before the measurement is made Per Cycle will appply an algorithm to detect whole numbers of cycles and apply the measurement over that range Display on schematic will additionally display the measurment result on the schematic using a lable attached to the probe To add additional measurments click the Add Measurement button A new line will appear There is no limit to the number of measurements that may be applied To remove a measurement select the line to be removed then click Remove Measurement 265 User s Manual 266 Notes on Curve Measurement Algorithms Some of the measurements algorithms make some assumptions about the wave shape being analysed These work well in most cases but are not fool proof The following notes describe how the
399. ronous and combinational logic as well as ROMS and RAMs Models for saturable magnetic components including support for air gaps User definable fixed and popup menus and key definitions What is SIMPLIS SIMPLIS is a circuit simulator designed for rapid modelling of switching power systems An acronym for SIMulation for Piecewise LInear System it is supplied with our SIMetrix SIMPLIS product range SIMPLIS is a component level simulator like SPICE but is typically 10 to 50 times faster when simulating switching circuits It achieves its speed by modelling devices using a series of straight line segments rather than solving non linear equations as SPICE does By modelling devices in this way SIMPLIS can characterise a complete system as a cyclical sequence of linear circuit topologies This is an accurate representation of a typical switching power system where the semiconductor devices function as switches However a linear system can be solved very much more rapidly than the non linear systems that SPICE handles The end result is accurate but extremely fast simulations allowing the modelling of complex topologies that would not be viable with SPICE SIMPLIS has three analysis modes Transient Periodic Operating Point and AC Transient analysis is similar to the SPICE equivalent but is typically 10 50 times faster Periodic Operating Point is a unique analysis mode that finds the steady state operating waveforms of switching s
400. roperty lt ref gt REF otherwise lt ref gt SMODEL lt sep gt REF Where lt sep gt is the separator character This is usually but can be changed at the netlist command line See Netlist command syntax in the Script Reference Manual If lt REF gt is used for a series or parallel repeat sequence it will be appended with lt SEP gt lt STEP gt where lt STEP gt is the sequence number for the series parallel function See below REPEAT lt REPEAT var_name num lt line gt gt Repeats line num times var_name is incremented on each step var_name may be used in an expression to define device or node names The following example creates a subcircuit that define an RC ladder circuit with a variable number of sections defined by the property NUM The resistance of each section is defined by the property RES and the capacitance by the property CAP Note that as explained above templates are resolved in two passes In the first pass the property names enclosed by are substituted with their values while expressions and keywords are left untouched In the second pass the keywords and expressions are processed subckt ladder 1 NUM 1 gnd lt repeat idx SNUM lt X idx idx idx 1 gnd section gt gt subckt section in out gnd Rl in out RES C1 out gnd SCAP Chapter 4 Schematic Editor ends ends var_name in the above is set to idx If NUM were set to ten the line X idx idx idx l gnd section
401. rpOrder Numeric Default 2 Sets interpolation order for the FFT calculation used for distortion measurments Chapter 14 Sundry Topics Name Type Description User interface support InterpPts InvertCursors LibraryDiagnostics LicenseDisableFast Checkout LogicDefExtension MaxHighlightColours MaxVectorBufferSize MicronComponentButtons MinGridHeight Numeric Boolean Text Boolean Text Numeric Numeric Text Numeric Default 1024 Sets number of interpolated points for the FFT calculation used for distortion measurments Default false If true schematic and graph mouse cursors are modified to be suitable for use on a black background Default Full Options Possible values Partial dialog None and Full Affects progress information displayed during model library searching Default false Affects network licenses only If set the license checkout process may take longer delaying the time it takes SIMetrix to start Default lIdf Options File extension used for dialog logic definition files Default 4 Maximum number of different colours used for schematic highlighting Default 32768 See the Simulator Reference Manual for a full explanation See Chapter 7 Script Reference Manual Creating and Modifying Toolbars for details Minimum allowed height of Options graph grid dialog 371 User s Manual 372 Name Type Description User interface
402. rranging the subcircuit pins is not desirable you can instead specify the pin order using the mapping value The mapping value is a list of symbol pin numbers that match to the corresponding subcircuit terminal So a mapping value of 2 3 1 says that the first subcircuit terminal connects to pin 2 of the symbol the second subcircuit terminal connects to pin 3 and the third to pin 1 169 User s Manual 170 Example SUBCKT IRF530 DGS ASSOC Category NMOS Symbol nmos_sub ENDS Priorities Its possible that association information could be provided from multiple sources in which case the possibility of conflict arises If this is the case the following priorities apply 1 User supplied association e g using the associate symbols and models dialog takes precedence over embedded association 2 Embedded association takes precedence over pre defined association Pre defined association is what is stored in the ALL CAT catalog file supplied with SIMetrix Catalog Files The data for model and symbol associations are stored in catalog files There are three catalog files as follows ALL CAT Resides in SIMetrix root directory Stores catalog data supplied with SIMetrix SIMetrix never modifies this file USER_V2 CAT Resides in the application data directory see Application Data Directory on page 355 Stores catalog data supplied by the user Data in this file overrides data in ALL CAT The Associate Models dia
403. rs can be moved horizontally or vertically while tracking an attached curve or they can be picked up and dragged onto another curve Initially there are just two cursors but there is the facility to add additional cursors without any maximum limit Cursor Operations Displaying To switch on off the cursor display select the graph menu CursorslToggle On Off Moving Cursors can be moved by a number of methods 1 Left to right In this mode the x position of the cursor is varied while the cursor tracks the curve to which it is attached To use this method place the mouse on the vertical crosshair but away from the intersection with the horizontal crosshair You should see the mouse cursor shape change to a left right arrow Press left mouse key and drag 2 Up down Similar to 1 above but instead the y position is varied To use this method place the mouse on the horizontal crosshair but away from the 255 User s Manual 256 intersection with the vertical crosshair You should see the mouse cursor shape change to an up down arrow Press left mouse key and drag 9 Drag and drop In this mode the cursor is picked up and moved without tracking any curve It can be dropped to any location and will then snap to the nearest curve To use this method place the mouse cursor at the intersection of the crosshairs You will see the cursor shape change to a four pointed arrow Press left key and drag to new location S The refe
404. s Note that PSpice schematics do not contain local copies of their symbols unlike SIMetrix so the symbol libraries are essential to perform any schematic translation For information see the on line help topic Schematic Editor gt gt PSpice Schematics Translation Reading PSpice Schematics Once the translator has been configured simply open the PSpice schematic in the same way as you would one created by SIMetrix Installing PSpice Libraries for Use with SIMetrix You can install PSpice symbol libraries in the same way as SIMetrix symbol libraries This will make the symbols available for use with SIMetrix Note that the schematic translator only uses symbols in the PSpice libraries specified using the procedure described above What the Translator will do 1 The translator will convert symbols parts and wires and display them in a manner that is as close as reasonably possible to the original schematic 2 TIt will convert any TEMPLATE properties to the SIMetrix format while preserving the original PSpice template under a different name 3 It will copy where possible any simulator commands to the F11 window 4 Hierarchical symbols will be appropriately converted but the underlying schematics need to be converted separately and saved in SIMetrix format 111 User s Manual 5 Translated symbols will be copied to PSPICE SXSLB in the SymbolLibraries directory By default this library is not installed If you do install it
405. s available as a PDF file on the install CD see Install CD on page 16 and at our web site The functions described here aren t the only functions that may be used in the expression for performance analysis They are simply the ones that can convert the array data that the simulator generates into a single value with some useful meaning There are many other functions that process simulation vectors to produce another vector for example log sqrt sin cos and many more These are defined in Function Reference on page 319 Of particular interest is the Truncate function described on page 329 This selects data over a given X range so you can apply a goal function to work on only a specific part of the data Primitive Functions The following primitive functions may be used as goal functions Not all actually return a single value Some return an array and the result would need to be indexed Maxima is an example Chapter 9 Graphs Probes and Data Analysis Name Description Page Maxima real real string Returns array of all maximum turning 326 points Maximum real complex Returns the largest value ina given 326 real real range Mean real complex Returns the mean of all values You 326 should not use this for transient analysis data as it fails to take account of the varying step size Use Mean1 instead Mean1 real real real Finds the true mean accounting for 327 the interval between data poi
406. s produces a continuous output i e it does wrap from 180 degrees to 180 degrees phase_rad real complex Identical to ph and phase functions except that the result is in radians Range real complex real real Vector Start index Default 0 End index Default vector length 1 Returns a vector which is a range of the input vector in argument 1 The range extends from the indexes specified by arguments 2 and 3 If argument 3 is not supplied the range extends to the end of the input vector If neither arguments 2 or 3 are supplied the input vector is returned unmodified re real complex real real complex Returns the real part of the complex argument Ref real complex Returns the reference or x values of the argument Rms real Returns a vector of the accumulative RMS value of the input Unlike RMS1 this function returns a vector which can be plotted RMS1 real real real Start x value Default start of vector End x value Default end of vector Returns the root mean square value of the supplied vector between the ranges specified by arguments 2 and 3 If the values supplied for argument 2 and or 3 do not lie on sample points second order interpolation will be used to estimate y values at those points Chapter 11 Command and Function Reference rnd real Returns a vector with each element a random value between 0 and the absolute value of the argument s corresponding element Root
407. s the x value of the first point on the curve that crosses Y max db_down starting at X max and scanning right to left Note that data is assumed to be raw simulation data and may be complex It must not be in dBs Implemented by built in script uf_hpbw Source may be obtained from the install CD see Install CD on page 16 LPBW LPBW lt data db_down Finds low pass bandwidth Chapter 9 Graphs Probes and Data Analysis Y max db_down Returns the value of X1 as shown in the above diagram Y max is the y value at the maximum point X max is the x value at the maximum point X1 is the x value of the first point on the curve that crosses Y max db_down starting at X max and scanning left to right Note that data is assumed to be raw simulation data and may be complex It must not be in dBs Implemented by built in script uf_lpbw Source may be obtained from the install CD see Install CD on page 16 Overshoot Overshoot data xStart xEnd Finds overshoot in percent Returns yMax yStart yStart yEnd Where yMax is the largest value found in the interval between xStart and xEnd yStart is the y value at xStart yEnd is the y value at xEnd If xStart is omitted it defaults to the x value of the first data point If xEnd is omitted it defaults to the x value of the last data point Implemented by built in script uf_overshoot Source may be obtained from the install CD see Insta
408. schematic To enter a device pin current hold down the shift key and click on the device pin in the schematic Both voltages and currents may also be selected from the Available Vectors box You may also plot an expression based on any curve that is already plotted Simply click on the curve itself and you should see a function entered in the form cv n where n is some integer Any entries made in this box are stored for future retrieval Use the drop down box to select a previous entry Expression for X data Only required for X Y plot and you must check X Y Plot box Expression entered in the same way as for Y data Lists values available for plotting This is for finding vectors that aren t on a schematic either because the simulation was made direct from a netlist or because the vector is for a voltage or current in a sub circuit You need to tell SIMetrix to save sub circuit currents and voltages using KEEP for details see page 216 of the Simulator Reference Manual Press Edit Filter to alter selection that is displayed See below 239 User s Manual 240 The names displayed are the names of the vectors created by the simulator The names of node voltages are the same as the names of the nodes themselves The names for device currents are composed of device name followed by a followed by the pin name Note that some devices output internal node voltages which could get confused with pin currents E g q1 base is the i
409. se on the schematic from the Place menu or tool bar this is the value first displayed This can of course be subsequently changed The initial value of Q2N2222 is defined in the NPN symbol However if you edit the symbol definition and change the initial value to something else say BC547 the value of the value property for any instances of that symbol that are already placed will not change You can use the popup menu Restore Properties to restore properties to their symbol defined values For more information see Restoring Properties on page 97 If you wish a property value to always follow the definition in the symbol then you must protect it See Defining Properties on page 87 for details Summary of Simulator Devices The following information is needed to define schematic symbols for the various devices supported by the simulator In order to be able to cross probe pin currents the pin names for the schematic symbol must match up with those used by the simulator So for a BJT bipolar junction transistor the simulator refers to the four pins as b c e and s for base collector emitter and substrate The same letters must also be used for the pin names for any schematic BJT symbol The simulator device pin names are listed below The model property is the schematic symbol property which describes what type of device the symbol refers to SPICE uses the first letter of the component reference
410. see Symbol Library Manager these symbols can then be used in SIMetrix schematics Limitations The translator has the following limitations 1 2 3 4 It cannot convert busses Boxes text boxes free text and embedded graphics are not supported Pin attributes are not supported Hierarchical blocks are not supported but hierarchical symbols are To use hierarchical blocks use PSpice to convert them to symbols The template properties are converted to the SIMetrix format but with one limitation References to properties that are themselves templates are not supported These are used in some of the standard ABM blocks supplied with PSpice These will need to be manually converted by editing the template property You will not normally be able to cross probe current into a device converted from PSpice The current into the device will be available but the schematic cross probing mechanism won t work without manually editing the symbols and template property PSpice Schematics allows the placement of symbol pins parts and wires off grid The translator will convert these correctly and SIMetrix will display them correctly but they can cause problems if attempting to edit them subsequently SIMetrix itself does not permit the user to place off grid items If off grid parts are identified they will be highlighted and a warning will be displayed Off grid symbols will also resulting in a warning If possible we recommend that these ar
411. sees ened iina E length ANY ierra a e ea ear e de ria aa ar EREEREER In real compleX sssssssessreenrennnenrrnennnnsnnnrsnnarnnnne log10 real complex log real complex mag real complex magnitude real complex Maxidx real COMPIeX eeeeeeeeeseeeeeneeeteneeeesaeeeees Maxima real real String c e Maximum real complex real real eee Mean real COMPIEX eeeeeeeseeeesneeeeeneeeesneeeteneeees Mean1 real real real n e Minidx real COMPIeX ee eeeeseeeeeseeeeeeneeeeeneeeeeneeeeee Minima real real String ceecee Minimum real complex real real eee norm real COMPIeX eeeeeeeeeeeeseeeeeeeeeeeeneeeeeseeeees ph real complex phase real complex 0 Table of Contents phase_rad real COMPleX escceeeseeeeeseeeeesneeeeneees 328 Range real complex real real c e 328 re real complex real real cOMmplex ceeeeee 328 Ref real COMPIeX eeesceeeeseeeeeneeeesneeereneeeeesaeereaas 328 RIms re al i is ceecisctedesaceescgdasteccdvsegsbasaschscaceaasatt SES eiS 328 RMS1 real real real ee eeeeeeeeeeeeeseeeteeeeneerees 328 TNO al as cccessatcedsecensicecepeseciarassceesaagzeee cpaiacndeviecunaae 329 RootSumOfSquares real real real eeee 329 SIQN rGal iced ein ee eee eee eee 329 sin real complex eee eeseeeeeneeeteneeeeeneeeeseeeseneeees 329 Saqrt real COMPIeX eeeeeeeeeeeeneees
412. specify a name of your choice To Find an Assigned Net Name Place the mouse cursor on the net of interest You will see the name appear in the fifth entry of the status box at the base of the schematic window in the form NET netname Note that the schematic must have been netlisted for this to work Netlisting occurs when you run a simulation for example but you can force this at anytime by selecting the menu Simulator Check To Specify a User Defined Name User defined net names can be specified using either the Terminal symbol or the Small Terminal symbol Select menu PlacelConnectors Terminal or PlacelConnectors Small Terminal To specify the net name select the terminal then press F7 and enter your choice of name Hierarchical Schematic Entry Schematics can be organised into multiple levels in a hierarchy Typically the top level would contain a number of blocks each of which represents an underlying child schematic Each of the child schematics can in turn contain more blocks 72 Chapter 4 Schematic Editor You can create a hierarchical schematic in one of two ways Top down method Blocks are created first to make a functional diagram The underlying schematic for each block is created afterwards Bottom up method Schematics are designed first then blocks are created to use with them The schematic and its symbol are stored within the same file The combined element is known as a component and is usually given the
413. store the session select menu File Restore Session Where is Session Data Stored Session data is stored in the following directory application_data session where application_data is the SIMetrix application data directory See Application Data Directory on page 355 for details Symbolic Path Names Overview Some file system path names used by SIMetrix may be defined using a symbolic constant Such paths are of the form Y osymbol path 351 User s Manual 352 Where symbol is the name of the constant and path is any sequence of characters valid for a path name The actual path is resolved by substituting symbol with the value of symbol Symbolic paths make it easy to move files to new locations as only the values for their symbols need to be changed in order for SIMetrix to be able to continue to find them Definition There are two types of symbolic constant These are system constants and user constants system constants are pre defined while user constants can be arbitrarily defined by the user There are currently 7 system constants These are STARTPATH Full path of the current working directory from where SIMetrix was launched DOCSPATH Full path of the My Documents folder on Windows HOME on Linux EXEPATH Full path of the location of the SIMetrix binary SIMetrix exe on Windows SIMetrix on Linux APPDATAPATH Full path of the Application Data directory TEMPPATH Path of temporary directory SXAPPDA
414. t Default Alt No Controls vertical text display when copying graphs to the Windows clipboard Default setting has been found to be reliable and it isn t usually necessary to change it If you find a target application does not display the y axis labels correctly try values of Normal use a different method to rotate text Hide hides vertical text or Horiz displays vertical text horizontally Default SXAPPDATAPA TH veriloghdl Location of Verilog HDL files Currently only the cache data is stored here Default 1000 Maximum number of cache entries for Verilog HDL module info cache Default false No If true a warning will be issued if unexpected simulator commands are found in subcircuits Width in pixels of No schematic lines Default 1 Default sxappdatapath No out Location and basename without extension of working catalog file OUT CAT 381 User s Manual 382 File Extension The following options set default file extensions See options dialog for more details Option name Default Description value CatalogExtension cat Catalog files ComponentExtension sxcmp Schematic component files DataExtension sxdat dat Data files GraphExtension sxgph Graph binary files LogicDefExtension ldf Arbitrary block logic definition files ModelExtension Ib lib mod cir SPICE model files SchematicExtension sxsch sch Schematic files ScriptExtension sxscr txt Scripts SnapshotExtension sxsnp Si
415. t The following dialog will open J Edit Curve Marker x Properties Label Text Alignment curvelabel 7 Automatic Left Bottom Font items enclosed with are symbolic values and are resolved when displayed E g curve label resolves to the name of the curve to which the marker points See help for details kD Ee ae Label Text of the marker s label curve label automatically resolves to the curve s label If the curve name is edited with menu CurveslRename curve this value will reflect the change You can of course enter any text in this box You can also use expressions in the same manner as for cursor dimensions See Label on page 258 Text Alignment This is how the label is aligned to the arrowed line If set to automatic the alignment will be chosen to be the most appropriate for the relative position of the label and the arrowhead Uncheck automatic and select from the list to fix at a particular alignment Font Press Edit Font to change font for text Other Properties Snap To Curve You can switch off the action that causes curve markers to always snap to a curve Select Properties tab then double click on SnapToCurve item Select Off You will now be able to move the curve marker to any location Chapter 9 Graphs Probes and Data Analysis Legend Box Placing Select menu AnnotatelAdd Legend Box A box listing all the curve names will appear at the top left of the
416. t the fundamental frequency is specified and also that the simulated signal is consistent over a large number of cycles The rectangular window however usually gives considerably poorer results and must be used with caution Probing Busses It is possible to probe a bus in which case a plot representing all the signals on the bus will be created Usually this will be a numeric display of the digital bus data but it is also possible to display the data as an analog waveform Buses may contain either Chapter 9 Graphs Probes and Data Analysis digital or analog signals if any analog signals are present then threshold values must be supplied to define the logic levels of the analog signals To probe bus using default settings Use the schematic popup menu Probe Voltage or hot key F4 and probe the bus in the same way as you would a single wire This will plot a numeric trace using decimal values To probe bus using custom settings 1 Select menu ProbelVoltage Bus 2 Click on desired bus 3 Enter the desired bus parameters as described in Bus Probe Options below Bus Probe Options The following describes the options available for random and fixed bus probes These options are set using the dialog box shown below See Probing Busses above and Fixed Probe Options on page 224 for details on plotting busses J Define Bus Plot Bus Definition Probe Options Define Bus Analog Thresholds Labe
417. t the right and the AC tab at the top You will need to enter some values in the Sweep Parameters section 52 Chapter 3 Getting Started Transient AC Dc Noise TF SOA Options Sweep parameters Points per decade 25 Start frequency Ik a Decade Stop frequency 1Meg 3 Linear a S Mode Frequency The analysis will sweep the frequency over the range specified by Start frequency Stop frequency and Number of points or Points per decade if you select a decade sweep Frequency sweep is just 1 of 6 modes available with AC sweep The Define button allows you to specify one of the others See AC Sweep on page 188 for details Noise Frequency Sweep Like AC analysis Noise analysis is a small signal mode Over a user defined frequency range the circuit is treated as linear about its DC operating point and the contribution of all noisy devices to a designated output is computed The total noise at that output is also calculated and optionally the noise referred back to an input source may also be computed To set up a Noise Frequency Sweep select the Noise check box at the right and the Noise tab at the top You will need to enter some values in the Sweep Parameters section Transient AC E Noise TF SOA Options Sweep parameters Start frequency 1k Ss Decade Stop frequency 1Meg a 5 Linear Points per decade 25 Mode Frequency The analysis will sweep the frequenc
418. ta yValue n X value at the Nth Y crossing 295 XatNthYn data yValue n X value at the Nth Y crossing with 296 negative slope XatNthYp data yValue n X value at the Nth Y crossing with 296 positive slope XatNthYpct data yValue n X value at the Nth Y crossing y 296 value specified as a percentage YatX data xValue Y value at xValue 296 YatXpct data xValue Y value at xValue specified as a 296 percentage BPBW Bandwidth BPBW data db_down Finds the bandwidth of a band pass response This is illustrated by the following graph 288 Chapter 9 Graphs Probes and Data Analysis First 3dB crossing after peak x2 Function return x2 x1 as shown in the above diagram Note that data is assumed to be raw simulation data and may be complex It must not be in dBs Implemented by built in script uf_bandwidth Source may be obtained from the install CD see Install CD on page 16 CentreFreq CenterFreq CentreFreq data db_down See diagram in BPBW Bandwidth above Function returns x1 x2 2 Both British and North American spellings of centre center are accepted Implemented by built in script uf_centre_freq Source may be obtained from the install CD see Install CD on page 16 Duty Duty data threshold 289 User s Manual 290 First ve crossing Firgt ve crossing of threshold X2 of threshold X1 Function returns X2 X1 X3 X1 X1 X2 and X3 are
419. ta to an integral number of whole cycles This is useful for measurements such as RMS which are only meaningful if applied to a whole number of cycles AC coupled Offsets the data by the mean value This is equivalent to AC coupling the data The above operations are performed in the order listed So for example the data is truncated to the cursor span before AC coupling 261 User s Manual 262 Custom Measurement If you select the Custom entry in the Choose measurement list the Custom measurement tab will be enabled The Custom measurement tab allows you to define your own measurement along with an option to add it to the list of pre defined measurements The following explains the entries in the Custom measurement tab Label as displayed on graph Expression Format template This is the label that will appear alongside the measurement value in the graph legend panel Usually this would be literal text but you may also enter a template string using special variables and script functions See Templates on page 264 for details Expression to define measurement Use the variable data to access the data for the curve being measured The expression must return a single value i e a scalar See Goal Functions on page 286 for details of functions that may be used to define measurement expressions Defines how the value will be displayed If you leave this blank a default will be used which w
420. tabilityPoint should be 180 The function detects the frequencies at which the magnitude of the gain is unity It then calculates the phase shift at those frequencies and returns the value that is numerically the smallest This might be negative indicating that the system is probably already unstable but could be conditionally stable If the gain of the system does not cross unity then no phase margin can be evaluated and the function will return an empty vector PulseWidth PulseWidth data threshold Chapter 9 Graphs Probes and Data Analysis Returns the pulse width of the first pulse in the data Refer to diagram for the Duty function on page 289 The PulseWidth function returns X2 Xi Default value for threshold is Ymax Ymin 2 Where Ymax largest value in data and Ymin in smallest value in data Implemented by built in script uf_pulse_width Source may be obtained from the install CD see Install CD on page 16 Rise Rise data xStart xEnd Amplitude V y Function returns the 10 to 90 rise time of the first rising edge that occurs between xl and x2 The 10 point is at y threshold Y1 Y2 Y1 0 1 and the 90 point is at y threshold Y1 Y2 Y1 0 9 Tf xStart is specified X1 xStart otherwise X1 x value of first point in data If xEnd is specified X2 xEnd otherwise X2 x value of last point in data If xStart is specified Yl y value at xStart otherwise Y1 maximum y v
421. tance would be in the real world e g the actual winding resistance of an inductor and never use an unrealitically small value Very small resistances e g 1 fempto Ohm can cause convergence problems For loops containing inductors you can break the loop by adding an initial condition to the inductor instead of adding a resistor Failure to observe the above usually leads to a Singular Matrix error 45 User s Manual Circuit Stimulus Most circuits require some form of input signal such as a pulse or sine wave Such signals or stimuli are specified using a voltage or current source which is placed on the schematic in the usual way A number of different types of source are available These are described in the following sections Waveform Generator This is used to create a time domain signal for transient analysis This generator will work in both SIMetrix and SIMPLIS modes of operation To place one of these devices select menu Placel Voltage Sources Waveform Generator for a voltage source or PlacelCurrent Sources Waveform Generator for a current source To specify the signal for the source select then choose the popup menu Edit Part or press F7 This will bring up the dialog box shown below In SIMPLIS simulation mode it will have an additional check box see notes below J Edit Waveform arc Time Frequency Wave shape z Square Period 3 Frequency 10k a E Width 50u 2 Duty 50 z iiine Soe pee Sawt
422. tartup script Here is the procedure 1 Select command shell menu File Scripts Edit Startup If you are using Linux you might first need to define a suitable text editor for this menu to work The default is gedit 2 Enter a DefButton command for each toolbar button you wish to redefine For the MOS symbols the commands will be one or more combinations of the following DefButton NMOS4 inst ne your_nmos4_symbol DefButton PMOS4 inst ne your_pmos4_symbol DefButton NMOS3IC inst ne your_nmos3_symbol DefButton PMOS3 IC inst ne your_pmos3_symbol 113 User s Manual 114 Replace your_nmos4_symbol your_pmos4_symbol etc with the internal names of your new symbols Automatic Area and Perimeter Calculation In the Micron versions of SIMetrix you can edit device length width and scale factor using the popup menu Edit MOS Length Width or by pressing alt F7 These menus alter the symbol properties W L and M for width length and multiplier The symbols described above have been designed in a manner such that additional parameters such as AS AD PS PD NRS and NRD may be automatically calculated from width and length To use this facility append the VALUE property with the parameter definitions defined as expressions E g N1 AD 2 3W S 0 8u The above device will have an AD parameter calculated from 2 width 0 8u Note that the formula is enclosed in curly braces and width and length
423. teeeeeeeeaees 151 OVEIVIEW lt a2ece eects a ea aes 151 Creating Soft Recovery Diode Models 151 SUBGCIFCUITS 2 EE deck tae eee hee aa 153 OVOIVIOW iieii Mace ei iiias 153 Creating a Sub circuit from a Schematic 154 Calling a Sub circuit in a Schematic 155 Special Components e eeeeeeeeeeeeeeeeeeeeeeeeeeteeeeeeeeaees 157 Initial Conditions 0 0 ec eee eee eeeeeeeeeteeeteeeeeaeteaeeeee 157 Nodesets tis ache ceieent eines atin nec 158 Eo E E ci ee See 158 Parameters and Expressions escceeeseeeseeeeeeneeeeee 159 Example neii ada ee as 159 Table of Contents Chapter6 Device Library and Parts Management Using Parts BrowSer esceeesseeeseeeeeereeeeeneeeeeneeeeenaees 162 Parts Management Installing Models ee eee 163 OVEIVIOW stele els aie e nines 163 Procedure isi sets ei a aa ee end le A levees iach 163 Full Model Installation Procedure essere 163 Removing Model Libraries 167 Parts Management Advanced TOpics sseeeee 167 Associating Multiple Models with Symbols 167 Embedded Association 169 Catalog Files senres eee aeit 170 Importing Models to a Schematic eeeeeeeee 171 Sundry TOPICS lt fii sceis Sens eaa taane det seston die ieciapaseesaee st 171 EIB COntrO listens nies eet daeead eee Bala 171 Drag and Drop to Schematic cecceeeeeeeeeeeeees 172 Library Diagnostics eee eeeeeeeseeeee
424. tell the difference from the syntax alone To resolve this SIMetrix is shipped with a database of known part numbers providing a named schematic symbol component category and if relevant a pin mapping order If the part is in the database no further action is required by the user and the part will appear in the browser under the correct category and select the correct symbol If the model is not in the database and has 2 or 3 terminals then SIMetrix will attempt to determine the type of device by performing some tests on the model using simulation If this process is successful SIMetrix will choose an appropriate schematic symbol without further action required If SIMetrix cannot determine what the device is then in order to use the device on a schematic you will need to provide the association information You will be prompted for this information when you place a part on the schematic for the first time and this is often the most convenient method However there is also a method of providing the association information in bulk which is advantageous in many cases Procedure There are two stages to installing SPICE models 1 Install the model itself so that the program knows where to look for it This is simply a matter of dropping files or folders on the command shell See Installing Electrical Model below 2 Associate the model s with a schematic symbol This process is often automatic and you don t need to do anything see
425. tep analyses are defined using the same 6 sweep modes used for the individual swept analyses in addition to snapshot mode See Transient Snapshots on page 179 for details of snapshots The 6 modes are briefly described below Note that Monte Carlo analysis is the subject of a whole chapter see Monte Carlo Analysis on page 332 e Device Steps the principal value of a device E g the resistance of a resistor voltage of a voltage source etc The component reference of the device must be specified e Model parameter Steps the value of a single model parameter The name of the model and the parameter name must be specified e Temperature Steps global circuit temperature Parameter Steps a parameter that may be referenced in an expression e Frequency Steps global frequency for AC Noise and Transfer Function analyses Monte carlo Repeats run a specified number of times with tolerances enabled As well as 6 different modes there are 3 different sweep methods which can be applied to all modes except Monte Carlo These are Linear Decade List The simulator also offers an Octal sweep method but this is not supported by the Choose Analysis Dialog Setting up a Multi step Analysis Define Transient AC DC Noise or Transfer Function as required then check Enable Multi step and press Define button For transient DC analysis you will see the following dialog box Other analysis modes will be the same except that th
426. tes on Curve Measurement Algorithms 266 Plots from curves 0 eeeseeeeneeeeseneeeeseeeteneeeeeeeeraes 267 Graph Zooming and Scrolling cccccceeeeeeseeeeeeeeeees 268 Annotating a Graph 0 0 eeccececeeeeeeeneeeeeeeeeeeeeeteaeeeeeeees 269 Curve Markers ceeceeecceeseeesceseaeeeeeeseeseeeeeeeenaees 269 Legend Box isapan aan aeaaeai eis 271 TOXU BOX EEE EEE A E A 272 Caption and Free Text eecceeseeeeeeeeeeeeneeeeeeetens 272 Graph Symbolic Values e cecceeeceeeeeeeeeeeeeeeees 273 Copying to the Clipboard eeeeeeeseseeeeeeeeeeneeeeeeeeees 275 OVEIVIOW 2ec c0s loc cdeeseeceids cote endes iiin s 275 Copy Data to the Clipboard cccceeseeeeeees 276 Copying Graphics to the Clipboard 006 276 Paste Data from the Clipboard eeeeeeseeeeeees 276 Using the Internal Clipboard ceeeeeeeeeeeeeeees 276 Exporting Graphics sirere esipaari eroana ao ionadk naain 277 Saving Graphs snatch at a aa dal aa E a a 277 SAVING DEREAT EL T veaceatiapisedtiastiaeece crease 278 Restoring hie Re ld deed et 278 Viewing DC Operating Point Resullts ceeeeeeee 278 Table of Contents Schematic Annotation cceccceeceeeeeseseeeeeeeeteaes 278 Displaying Device Operating Point Info 278 List File Data stii aanpoten ebisapiveu hast 278 Other Methods of Obtaining Bias Data 279 Bias Annotation in SIMPLIS ssassn 279 Bias Ann
427. text is always horizontal when absolute is selected the text is vertical when the symbol is at a 90 degree rotation When auto is selected this specifies which side of the symbol the text is located when the symbol is in normal orientation When auto is selected this specifies which side of the symbol the text is located when the symbol is rotated 90 degrees Defines the reference point on the text when absolute is specified See diagram below for meaning of options The reference point is always at a fixed location with respect to the symbol body The position of the remainder of the text may vary with zoom level or font size Centre Property Text The property s value text will not be displayed in the schematic Top Base line If checked the property will be displayed vertically This option is only available if absolute location is selected Property Attributes Font style Selectable Protected Linear Show Name Resolve symbolic Select one of eight font styles The actual font definition is defined by the Font dialog box See page 385 for details If checked the instance of the symbol owning the property can be selected by clicking in the property text It is recommended that this option is off unless the symbol has no body e g a pure text item If checked it will not be possible to edit or delete the property on a schematic instance of the symbol When this is not checked the size of the font
428. the curves while the remaining lines will contain the curves data arranged in columns Copying Graphics to the Clipboard Note that this feature is not currently available in the Linux environment There are three different ways a graph can be copied to the clipboard Use the menus under EditlCopy Graphics These are detailed below Colour Copies graph to clipboard in full colour The curve legends identify the curves using coloured squares similar to how the graph is displayed on the screen Monochrome Copies graph to clipboard in monochrome Curves are distinguished using varying markers and line styles Curve legends distinguished curves with a straight line example Colour with markers Copies graph to clipboard in full colour but also differentiates curves using markers and line styles Curve legends distinguished curves with a straight line example Paste Data from the Clipboard SIMetrix can plot curves using tabulated ASCII data from the clipboard The format is the same as used for exporting data See Copy Data to the Clipboard above for more details Using the Internal Clipboard The menus EditlCopy EditlCut and EditlPaste all use the internal clipboard These menus are intended to allow the moving or copying of curves to new graphs Note that these menus do not use the system clipboard at all See above sections for details on how to copy and paste from the system clipboard The internal clipboard uses an efficient
429. the normal way and in fact the back annotation operation will be reversed with a single Undo operation Disable Enable Initial Conditions To disable initial conditions select menu SimulatorlInitial ConditionsIDisable Note that this will disable all initial conditions defined at the top level not just ones that are back annotated To re enable use the menu SimulatorlInitial ConditionslEnable Back annotation Errors If you get the error message The following instances have initial condition values but do not support back annotation it means that the SIMPLIS_TEMPLATE property is protected for the instances listed To fix the problem remove the protection on this property You will need to open the symbol in the symbol editor to do this In order to apply back annotation in a generic fashion SIMetrix needs to modify the SIMPLIS_TEMPLATE property but cannot do so if it protected hence the error message You shouldn t get this error with any standard symbols from the SIMetrix v5 library or later but you may get it with your own symbols or symbols from an earlier library Editing Back annotated Initial Conditions How you change the value of an back annotated initial condition depends on the device If the device already has a user editable initial condition then simply use the standard method With capacitors and inductors this is simply done using F7 or the Edit Part menu With some other devices the initial condition value may b
430. tial voltage 60 61 in hierarchy 228 list of types 223 options 224 persistence 225 voltage 59 fixed vs random 222 fourier phase 234 fourier spectrum 232 impedance 230 in hierarchical designs 243 old results 251 random 60 228 245 busses 236 current 60 dB 61 fourier 232 functions 229 phase 61 voltage 60 results from earlier run 251 PSP 207 PSpice schematic translator 110 configuring 111 opening schematics 111 symbol libraries 111 PSpiceIniPath option variable 353 375 PulseWidth function 294 R Random Probes 60 Range function 328 re function 328 ReadLogicCompatibility 313 real function 328 Real time noise analysis 193 RebuildConfig option variable 375 ref template property keyword 102 Ref function 328 ref property 95 156 RELTOL 198 repeat template property keyword 102 RepeatPlace option variable 375 Reset command 314 398 Resistor additional parameters 134 editing values 134 non linear 151 sweeping 183 Restarting transient analysis 179 Rise function 295 Rise time calculating 266 RMS function 328 RMS function 328 rnd function 329 RootSumOfSquares function 329 Rotating schematic components 43 64 Running simulation 58 basic steps 42 hierarchical designs 58 S Saturation 130 SaveRhs command 314 Saving graphs 277 simulation data 279 Schematic annotating 70 bus connections 69 add 69 in hierarchy 75 probing 236 ripper 69 wiring 70 checking 71 copy to clipboard 70 creating 62 displayin
431. time to complete 323 User s Manual 324 im real complex imag real complex Returns imaginary part of argument integ real Integrates the argument with respect to its reference x values The function uses simple trapezoidal integration An error will occur if the argument supplied has no reference Interp real real real real Vector to be interpolated Number of points in result Interpolation order Boolean include last point Returns a vector with length specified by argument 2 obtained by interpolating the vector supplied as argument at evenly spaced intervals The optional third argument specifies the interpolation order This can be any integer or greater but in practice there are seldom reasons to use values greater than 4 The Interp function overcomes some of the problems caused by the fact that raw transient analysis results are unevenly spaced It is used by the FFT plotting scripts to provide evenly spaced sample points for the FFT function The Interp function also makes it possible to perform operations on two vectors that originated from different transient runs and therefore will have different sample points IsComplex any Returns 1 TRUE if the supplied argument is complex and 0 FALSE if the argument is any other type length any Returns the number of elements in the argument The result will be 1 for a scalar and 0 for an empty value The length function is the on
432. tions 357 382 bus probes 237 colours 385 dialog box 357 fixed probe 224 fonts 385 SIMPLIS 213 simulator 198 variables full list 363 382 GroupPersistence 252 Set command 315 UnSet command 316 UpdateClosedSchematics 244 OUT CAT 170 Overshoot calculating 266 function 293 P parallel template property keyword 104 Parameters 159 396 list file output 199 passing through hierarchy 78 passing through subcircuits 157 start up 354 sweeping 183 with multi step analysis 202 params property 96 Parts browser 162 PassUnresTemplate option variable 374 Path names symbolic 351 PeakToPeak function 294 Period function 294 Periodic operating point 209 211 ph function 328 Phase function 328 plotting 61 224 229 phase_rad function 328 pinlist template property keyword 100 pinnames template property keyword 101 Pins global 76 Plotting arbitrary expressions 238 noise analysis 231 results from earlier run 251 see also Probing transfer function analysis 231 X Y 239 POP 209 211 Potentiometer 136 Precision option variable 374 PrintOptions option variable 374 PrintWireWidth option variable 374 ProbeStartDelay option variable 375 ProbeUpdatePeriod option variable 375 Probing 58 61 221 222 245 arbitrary expressions 61 238 busses 236 device power 230 fixed 59 223 228 after run has started 228 changing update delay and period 228 359 Index 397 User s Manual current 60 differen
433. to the sub menu press Add Separator To Create a New Sub menu Select the location for your new menu then press Add Menu Enter the menu name as required The new sub menu will have one single empty item which you can select to add new items to the sub menu The empty item will not appear in SIMetrix menus To Edit or Add an Accelerator Key Select the menu item to which you wish to assign the accelerator key Press Accelerator You will now be asked to press a single key or key combination with shift control or alt The key you press will be assigned to the menu Press Remove to delete the accelerator key assignment To Reset to Factory Settings Press Reset to reset the menu system back to factory settings Usually this means that the menu system will revert to the structure defined when SIMetrix was first installed However if you defined any menus in the startup script using the DefMenu command these menus will be faithfully restored as well Reopen Menu The Reopen menu in the Command Shell File menu is dynamically updated to include schematic files recently opened or saved The items in this menu are not listed in the Menu Editor and cannot be edited The Reopen sub menu itself should not be deleted or moved to a new sub menu nor should it be renamed but it may be repositioned in the command shell s File menu as desired User Defined Toolbars and Buttons All toolbars and buttons are user definable
434. ts alignment Hidden Check this box if you do not wish the pin name to be visible on the schematic Vertical The pin s label will be displayed vertically if this is checked Attributes Font style Select font style to use for a visible pin name There is a choice of 8 styles Schematic fonts are explained on page 385 Placing Multiple Pins To place more than one pin select menu Property Pin Place Pin repeated You will be prompted to supply a Base pin name which will be used to compose the actual pin name SIMetrix will append a number to this name to make the pin name unique The first number used will be 0 unless you append the Base name with a number in which case your appended number will be used as the starting point For example if you supplied a Base name of DATA the first pin placed will be called DATAO the second DATA etc assuming there aren t already pins of that name on the sheet If you supplied a base name of DATA2 the first pin you place will be called DATA2 the second DATA3 etc Editing Multiple Pins You can only edit the names of pins one at a time but you can edit the attributes of a group of pins in a single operation First select all of the pins you wish to edit Selecting is done in the same manner as for the schematic except note that you can select the pins themselves or the pin names either will do Now press F7 or select popup menu Edit Property Pin Arc You can change any of the pins attributes exc
435. ts ict otis EE int eta dahon bee 80 Exporting Schematic Graphics ecceeeeeceeeeees 81 Exporting to Earlier Versions of SlMetrix 81 ASCIilformat isi ararat eileen 81 TANDIL V e PPE TEA 82 Creating Schematic Symbols Overview c0008 82 Graphical Symbol Editor cceeeeeeeeeseeeeeeeeeeeeeeeeeeeees 83 Table of Contents EEA seater T 83 Symbol Editor Window eccesceeseeeeeeeeeeeteeeeeeeees 83 The Elements of a Symbol c ceeeeeeeeeeeeeeeeeetees 83 Creating a New SyMbol eeceecceeeeeeeeseeeeteeeeeeeaes 84 Editing an Existing Symbol cceeceeeeeeeeeeeeenees 84 Drawing Straight Line Segment cceseeeeeees 84 Drawing Arcs Circles and Ellipses ceeeeee 84 Placing and Defining Pins eeeeseeeeseeeeseeereneees 85 Defining Properties 0 eeeeeeeseeesneeeeseeeeeneeeeeneees 87 Saving Symbols isi iiien niset aeeie ai iainta 92 Creating a Symbol from a SCript ec eeeeeeeeeeeeseeeeeeeees 93 Properties minigona e a 94 OVEIVIOW si doeii e eE iin setae es 94 What is a Property 0 0 eceesceeeeeeeeeeeeeeeseeeeeeeeeeeees 94 Template Property 0 00 eeeceeesseeeeseeeeeeneeeeeneeereneees 96 Editing Properties in a Schematic ceeee 97 Restoring Properties eceeeeseeeseeteeseeeeeeneeeeeneees 97 Template Property ccessceceseeeesseeeeesceerenseeeessneeesscees 97 OVENVIEWS n erei date Beit Ghee 97 Template
436. tures while retaining backward compatibility At the time of writing schematics created with the latest SIMetrix version 6 2 remain readable with all versions from and including 4 1 However although the schematics may be viewed with older versions they won t necessarily simulate ASCII format SIMetrix schematics are usually saved in a binary format This is fast compact and can be read by earlier versions From version 5 0 a new ASCII based format was introduced The format used is fully documented allowing the development of translators to other formats Also there are some editing operations that are easier performed on an ASCII file than with the graphical editor For example changing a symbol name is very difficult with the 81 User s Manual schematic editor as you have to delete and replace all instances But this is a simple task with a text editor operating on the ASCII file Saving in ASCII Format To save a schematic in the ASCII format use the menu FilelSave Special then select ASCII format Opening ASCII Schematics No special procedure is needed Just open the schematic in the usual way SIMetrix will detect that it is in the ASCII format automatically File Format Documentation for the format be found on the install CD see Install CD on page 16 may be found at cd drive letter Docs File Formats schematic ascii format revnnn pdf Windows or cd mount point Docs File Formats schematic ascii form
437. ty Subsequent random probe operations will use the new axis or grid unconditionally as long as it remains selected see below Selecting Axes Some operations are performed on the selected axis or grid The selected axis or grid will be displayed with its vertical axis line a deep black while the remaining axes and grids will be light grey Newly created axes and grids are always selected To select an axis click the left mouse button immediately to the left of the vertical axis line Stacking Curves to Multiple Grids The menu Curves Stack All Curves will place each curve on its own grid The menu Curves Stack Selected Curves will place each selected curve on its own grid Moving Curves to Different Axis or Grid You can freely move curves around from one axis or grid to another Proceed as follows 1 Select the curve or curves you wish to move by checking its checkbox next to the coloured legend which designates the curve 2 Select the axis you wish to move it to See above 3 Press the Move selected curves to new axis button The curves will be re drawn on the new axis Any axes that become empty as a result of this operation will be deleted unless it is the Main axis See section below on Deleting Axes Deleting Axes To delete an axis select it then press Erase axis button Note that you cannot erase an axis or grid that has curves attached to it nor can you erase the Main axis The main axis is the first axis th
438. u wanted to plot the voltage of a node inside U1 The schematic fastamp sxsch is open but to which block does it refer The answer is that it will refer to the most recent block that was used to descend into it The block that a schematic refers to is always displayed in the schematic s status bar as illustrated below Chapter 9 Graphs Probes and Data Analysis J CAUsers jrw Documer hierarchy AEE Selected Sc File Edit View Simulator Place Probe Probe AC Noise Hierarchy Monte Carlo Verilog GGG SIOBXCHe AQQ Z HELM rT OSCIKKET top sxsch fastamp sxcmp Cur Users jrw Documents SIMetrix Examples hierarchy top ssch gt lt lt Top level reference of block Pathname of root To plot a node in U2 ascend to parent top sxsch in the above example then descend into U2 The same schematic as above will be displayed but will now refer to U2 instead of U1 Plotting Currents In the same way that you can plot currents into subcircuits in a single sheet design so you can also plot currents into hierarchical blocks at any level Plot Journals and Updating Curves Overview You can repeat previous plotting operations in one of two ways The Update Curves feature rebuilds the current graph sheet using the latest available data This allows you to randomly probe a schematic and then update the curves with new results for a new simulation run 245
439. ues above all SIMetrix logarithm functions correctly handle complex arguments and return a complex value This means that the following expression to calculate dB will not produce the expected result 20 log data where data is a value produced by an AC analysis simulation What you should do is 20 log mag data The mag function will convert the complex data to real values which is actually what is intended Better still use db data This is equivalent to 20 log mag data 325 User s Manual 326 Note that the graph system will always plot the magnitude of complex data But any expression presented for plotting will be evaluated as complex and only the final result is converted to real So 20 log data will be plotted as mag 20 log data This is not the same as 20 log mag data when data is complex mag real complex magnitude real complex Returns the magnitude of the argument This function is identical to the abs function maxidx real complex Returns index of the array element in argument with the largest magnitude Maxima real real string Vector Minimum value Default v0 Options array Possible values are xSort Sort output in order of x values nolnterp Don t interpolate Returns an array of values holding every maximum point in the supplied vector whose value is above argument 2 The value returned if noInterp is not specified is obtained by fitting a parabola to the m
440. ult transient runtime 100 x POP max period Specify 100u gt Convergence Sets the convergence criteria for the periodic operating point analysis The convergence criteria is satisfied when the relative change in each state variable between the start and end of a switching cycle is less than this parameter Iteration limit Sets the maximum number of iterations for the periodic operating point analysis Number of cycles output After a successful POP analysis and if there is no transient analysis specified SIMPLIS will generate the steady state time domain waveforms for an integral number switching cycles This option sets the number of cycles Use snapshot from previous transient analysis If checked POP is instructed to take advantage of the last data point of a previous transient simulation assuming the circuit and the initial conditions remained the same between the two simulation runs Output POP progress If checked the progress of the POP solution will be output to the data file for plotting etc This is useful for debugging Enable automatic transient analysis after a failed POP 211 User s Manual If POP fails a transient analysis automatically follows This is to help diagnose the cause of POP failure but is also useful in some cases where a subsequent transient may settle sufficiently to perform a study load transient behaviour For further details refer to the SIMPLIS Reference Manual See Cha
441. upply rejection of an amplifier to be measured in one analysis The same measurements could be performed using AC analysis but several of them would need to be run Transfer function mode also calculates output impedance or admittance and if an input source is specified input impedance Setting up a Transfer Function Analysis 1 Select menu SimulatorlChoose Analysis 2 Select TF check box on the right 3 Select TF tab at the top Enter parameters as described in the following sections Sweep Parameters Start value Stop value Defines sweep range stop and start values Points per decade Number of points Defines sweep range The number of points of the sweep is defined per decade for a decade sweep For a linear sweep you must enter the total number of points Define Sets up desired sweep mode See Setting up a Swept Analysis on page 185 Transfer Function Parameters Voltage Current Specify whether the output is a node voltage or device current Output node Output source This is compulsory If voltage mode is selected it is the name of the circuit node to which the gain of all circuit sources will be calculated It is the node name as it appears in the netlist Usually the schematic s netlist generator chooses the node names but we recommend that when running a transfer function analysis that you assign a user defined name to your designated output node To find out how to do this see Finding and Specifying Net Nam
442. using Show command Options set in print dialog Default 5 Width in pixels of schematic wires when printed No Print dialog Name ProbeFlushOnUpdate ProbeStartDelay ProbeUpdatePeriod PSpicelniPath RebuildConfig RepeatPlace Type Boolean Numeric Numeric Text Boolean Text Chapter 14 Sundry Topics Description Default false It is not usual to need to set this option Simulation data is buffered for performance reasons but this buffering can interfere with the incremental updates needed for fixed probes Usually SlMetrix deals with this problem automatically but this is not guaranteed to work in all cases In such situations fixed probes or GRAPH statements may not incrementally update correctly Setting this option may rectify this Default 1 Delay after start of simulation run before fixed probe graphs are first opened Default 0 5 seconds Update period for fixed probe graphs Path of PSPICE INI file needed for the PSpice Schematics translator Default true See Auto Configuration Options on page 383 Default Toolbar Controls when schematic placement is repeated Possible values Always Toolbar toolbar symbols only and Never User interface support Options dialog Options dialog Option dialog No Options dialog 375 User s Manual Name SchematicEditMode SchematicMoveMode SchematicReadOnly Sch
443. ust now modify the expression you have entered to give it an index value For the simple case of a single voltage or current just append it with index where index is the run number less 1 In this example the run number is 49 so we enter 48 for the index You should now have C4_P 48 displayed in the Y expression box Close box You should see a single curve plotted An alternative method of plotting single curves is given in Setting the Seed Value on page 337 Creating Histograms See Performance Analysis and Histograms on page 280 339 User s Manual 340 Chapter 13 Verilog HDL Simulation Chapter 13 Verilog HDL Simulation Overview The Verilog HDL feature provides the ability to simulate Verilog digital designs included in analog circuits The SIMetrix implementation uses an external Verilog simulator to achieve this and communicates with that simulator using the standard VPI programming interface Two open source Verilog simulators for Windows one for Linux are supplied for this purpose and these are installed with the SIMetrix installer SIMetrix Verilog is also compatible with Mentor Graphics ModelSim and this configuration is fully supported under Windows In principle any VPI compliant Verilog simulator may be used however the two open source programs supplied and ModelSim are the only ones that are tested and supported Interfacing an analog simulator with a digital HDL simulator is a
444. utput can be selected from either PlacelProbelVoltage Probe or ProbelPlace Fixed Voltage Probe or just by pressing B in the schematic editor 3 After placing the output probe double click to edit its label Enter this in the box titled Curve Label All the other options may be left at their defaults 4 For the pulse source V2 you can use PlacelVoltage Sources Universal Source or the Universal Source tool bar button 31 User s Manual 32 5 Double click V2 Edit the settings as shown below Pulse Sine Noise ac oc Text Offset Time Frequency Period B Frequency 200k 3 Width 1 95u S Duty ap 3 Rise 50n S V Equal rise and fall Fall 50n 5 E Default rise and fall Delay 0 8 Repetitive Single Pulse Step Vertical Minimum 0 S Ofset 25 5 Maximum 5 g Amplitude 5 g Maximum Apt fk Minimum Enable DC Enable AC Pulse Sine Noise 5 Text None Cancel Help This sets up a 200kHz 5V pulse source with 40 duty cycle and 50nS rise time 6 Set up the simulation by selecting the schematic menu SimulatorlChoose Analysis In the dialog box check Transient Usually we would set the Stop time but on this occasion the default 1mS is actually what we want Now select the Advanced Options button In the Integration method box select Gear integration This improves the simulation results for this typ
445. value In Monte Carlo mode runs are simply repeated the specified number of times with random distribution functions enabled Distribution functions return unity in normal analysis modes but in Monte Carlo mode they return a random number according to a specified tolerance and distribution Any model or device parameter may be defined in terms of such functions allowing an analysis of manufacturing yields to be performed 213 User s Manual 214 Comparison Between S IMetrix and SIMPLIS The multi step analysis modes offered in SIMetrix simulation mode achieve the same end result as the SIMPLIS multi step modes but their method of implementation is quite different SIMetrix multi step analyses are implemented within the simulator while the SIMPLIS multi step analyses are implemented by the front end using the scripting language The different approaches trade off speed with flexibility The approach used for SIMPLIS is more flexible while that used for SIMetrix is faster Setting up a SIMPLIS Multi step Parameter Analysis An Example We will begin with an example and will use one of the supplied example schematics First open the schematic Examples SIMPLIS Manual_Examples Example 1 example1 sxsch We will set up the system to repeat the analysis three times while varying R3 Proceed as follows 1 First we must define R3 s value in terms of an expression relating to a parameter To do this select R3 then press shift F7 Enter the
446. various properties most importantly the ref model and value properties If however a template property is specified this system is bypassed and the netlist entry is defined by the value of this property The template property value can contain a number of special keywords and characters that will be substituted during the netlist creation Values that can be substituted include node names pin names and the value of any property 97 User s Manual 98 There are three template keywords that define multiple lines to implement series or and parallel combinations ladder networks or arrays of devices Template Property Format The netlist entry for a device with a template property will be the literal text of the template property s value with certain special characters and words substituted Text enclosed by lt and gt are keywords and have a special meaning Text enclosed with is substituted with the value of the property whose name is enclosed by the character Finally text enclosed by curly braces and will be treated as an expression and will be evaluated Each of these is described in more detail in the following sections Property Substitution Any text enclosed with is substituted with the value of the property whose name is enclosed by the character So REF would be substituted with the value of the ref property Expressions Text enclosed by curly braces and will be treated as a
447. ve only need to be done once for each model Note If the message Chapter 6 Device Library and Parts Management Unknown file type xxx is displayed when you drop a file it means that no valid SPICE models were found in the file It does not mean the file has the wrong extension SIMetrix will accept any extension for model files with the exception of the extensions used for schematic or graph files sch sxsch and sxgph Removing Model Libraries Select Model Library View Remove Libraries A dialog box similar to that shown on page 164 above will be displayed but with the Available Libraries box empty Select the devices you wish to remove from the Selected Libraries box Parts Management Advanced Topics Associating Multiple Models with Symbols The procedure for installing model libraries above Full Model Installation Procedure on page 163 explains how to install the library and then if required associate each model individually as you place the device on the schematic In some situations you might wish to perform the association process in bulk that is for many devices at once To so this use the File Model Library Associate Models and Symbols menu This is what you will see 167 User s Manual 168 Associate Models and Symbols Am Select Devices Choose Category Unknown e Unassigned New Category SXOA1000 Define Symbol AD587 Auto Create Sy
448. ve xaxis label for example has two levels curve returns the ID of a curve then curve xaxis returns the id of an axis then curve xaxis label returns the label property belonging to the axis Full documentation is available in the Script Reference Manual Chapter 7 Graph Objects This lists the available objects and their property names There is also a sub heading titled Symbolic Values that explains the above However deducing all the different possibilities for symbolic values especially the indirect values requires some effort For this reason the following table has been compiled which lists a range of complete symbolic values that are meaningful for use in labels for various objects This list is not exhaustive but probably has everything that is useable Note that the symbolic variable names like everything in SIMetrix are not case sensitive Variable Description Can use with curve label Curve s label Curve marker curve shortlabel Curve s label without the Curve marker groupname suffix that is sometimes displayed curve xunit Curve s x axis units Curve marker curve yunit Curve s y axis units Curve marker X1 Curve s x value at curve marker Curve marker Ry 1 Curve s y value at curve marker Curve marker 273 User s Manual 274 Variable Description Can use with curve xaxis label curve yaxis label curve measurements graph maincursor x1 graph maincursor y1 graph re
449. very quick However if the data is from the most recent simulation SIMetrix needs to unhook it in order to be able to move the file This will make it impossible to resume the simulation if paused or restart the simulation transient only Note that if you specify a location on a different volume as the original data then the file s data has to be copied and for large data files this will take a long time Make new copy This makes a fresh copy of the data This option does not suffer from the drawbacks of moving the file but if the data file is large can take a very long time Restoring Simulation Data Select menu FilelDatalLoad Navigate to a directory where you have previously saved data files You can also reload data from temporary files using menu Filel DatalLoad Temporary Data Whether or not there will be any files available to opened depends on the temporary data file delete options See Graph Probe Data Analysis on page 359 for information about these options The error The process cannot access the file because it is being used by another process means that the temporary data file is still in use Unless the file is in use by another instance of SIMetrix you will be able to use its data by selecting its associated group Use menu Graphs and Data Analysis Change Data Group Performance Analysis and Histograms 280 Overview When running multi step analyses which generate multiple curves
450. very run so if you start a new run of the same circuit with a start time Start Saving Data equal to the stop time of the previous run SIMPLIS will not need to rerun the start and instead will load the snapshot state SIMPLIS will do this automatically The entries in this dialog section allow you to specify the saving of snapshots at other times as well as the end of a run This might be useful if you wanted to restart a run at some before the end of the previous run Enable snapshot output Check this box to enable saving of snapshot data Snapshots are always saved at the end of a run Snapshot interval This is the minimum duration between snapshots Max snapshots This is the maximum number of snapshots that will be saved This setting overrides Snapshot interval if there is a conflict Chapter 8 SIMPLIS Analysis Modes Average Topology Duration SIMPLIS calculates the average time it spends in each topology over a defined number of topologies If this value falls below a minimum value the simulation aborts The entries in the Average Topology Duration group define the parameters for this feature as follows Minimum If the avaerage time falls below this threshold the simulation will abort Measurement window Number of windows over which the average time will be calculated The purpose of this is to resolve problems with the simulation apparently getting stuck in situations where there are unexpected very high speed oscill
451. vices and VDD for PMOS devices Chapter 4 Schematic Editor Further Information How Symbols are Stored When a symbol is placed on a schematic a copy of that symbol definition is stored locally This makes it possible to open the schematic even if some of the symbols it uses are not available in the symbol library However if you edit a symbol definition for a schematic that is saved when you open that schematic it has a choice between its local copy of the symbol or the copy in the library Which it chooses depends on an option chosen when the symbol is saved When saving the symbol with the graphical editor you will see the check box All references to symbols automatically updated If this is checked then the schematic editor will always use the library symbol if present Tf not it will use its local copy If a schematic is using a local copy and you wish to update it to the current library version select the symbol or symbols then select the popup menu Update Symbol Note that all instances of the symbol will be updated It is not possible to have two versions of a symbol on the same schematic Important Note Note that only the symbol geometry pin definitions and protected properties of a schematic instance will be changed when its symbol definition is edited Unprotected properties will remain as they are For example the standard NPN bipolar transistor symbol has an initial value property of Q2N2222 so when you place one of the
452. visible properties on that symbol are converted to Absolute locations This is the only way that the positions of all properties can be preserved This means that once you move a single property on a component it and all other properties will rotate with the symbol For this reason it is better not to move property text until the orientation of the symbol has been finalised Wiring Overview SIMetrix offers both manual and smart wiring methods In smart mode you select the start and end points and SIMetrix will find a suitable route In manual mode you place each wire segment individually in exactly the locations you require You don t need to change global settings to select the mode you desire the procedures for each mode are different and so you can freely switch between them from one wiring operation to the next However in most applications you won t need to use the manual wiring method The smart wiring method can still be used to enter wire segments one by one simply by selecting start and end points that have an obvious straight line route The fundamental 67 User s Manual 68 difference between smart and manual is that smart mode will always route around obstacles such as existing wire terminations or whole symbols In manual mode the wire will always go exactly where you take it even it crosses existing connections or passes through existing symbols Smart Wiring Procedure 1 Initiate smart wiring by bringing th
453. w Graph Sheet Create a new graph sheet within current graph window New Graph Window Create a new graph window Axis Scales Sheet Allows you to specify limits for x and y axes J Define Curve Define Curve Axis Graph Options Axis Scales Axis Labels X Axis Y Axis Lin Log Auto ln log Atto 5 No change No change CESES Auto scale Defined Defined Min Min d ae d ae Max 1 Max 1 X Axis Y Axis Lin Log Auto Specify whether you want X Axis to be linear or logarithmic If Auto is selected the axis X or Y will be set to log if the x values are logarithmically spaced For the Y axis it is also necessary that the curve values are positive for a log axis to be selected Chapter 9 Graphs Probes and Data Analysis No Change Keep axes how they are Only relevant if adding to an existing graph Auto scale Set limits to fit curves Defined Set to limits defined in Min and Max boxes Axis Labels Sheet This sheet has four edit boxes allowing you to specify x and y axis labels as well as their units If any box is left blank a default value will be used or will remain unchanged if the axis already has a defined label Curve Arithmetic SIMetrix provides facilities for performing arithmetic on existing curves For example you can plot the difference between two plotted curves There are two methods 1 With the menus Plot Sum Two Curves Plot Subtr
454. w see another resistor symbol appear depending on how the system options are set Cancel this by clicking the right mouse button Now wire up the resistor There are a number of ways of doing this If you have a three button mouse or wheel mouse one way is to use the middle button or wheel Pressing it once will start a wire Pressing it again will fix it and start a new one Pressing the right button will terminate it If enabled you can also use the smart wiring method Just take the mouse pointer to the pin of the resistor You will see a pen symbol appear as the mouse gets close to the pin Left click then move the mouse cursor to the destination then left click again This method will automatically locate a route for the wire if one exists You can also enter wiring mode by selecting the toolbar wire button zZ This puts schematic into a permanent wiring mode where the left key is always used for wiring Revert to normal mode by pressing the wire button again Re run the simulation by pressing F9 The graph will now be updated to Amplifier Output mV Chapter 2 Quick Start 60 IfSt attempt 50 40 30 201 ith 0 2 4 6 8 10 Time uSecs 2uSecs div As you can see The problem with the trailing edge has been fixed and the ringing is much improved Now let s have a look at the ringing in more detail To do this we need to zoom in the graph by adjusting the limits of the axes Th
455. y a voltage controlled resistor with two terminals for the resistance and two control terminals Place one on the schematic with PlacelAnalog Functions Switch Editing using F7 or equivalent menu displays J Choose Switch Parameters x On Resistance i 2 Off Resistance 1Meg a Cancel On Voltage 3 8 Off Voltage 2 a If On Voltage gt Off Voltage If control voltage gt On Voltage Resistance On Resistance else if control voltage lt Off Voltage Resistance Off Resistance If Off Voltage gt On Voltage If control voltage gt Off Voltage Resistance Off Resistance else if control voltage lt On Voltage Resistance On Resistance If the control voltage lies between the On Voltage and Off Voltage the resistance will be somewhere between the on and off resistances using a law that assures a smooth transition between the on and off states Switch with Hysteresis An alternative switch device is available which abruptly switches between states rather than following a continuous V I characteristic This device can be used with both SIMetrix and SIMPLIS although the behaviour is slightly different in each The switching thresholds are governed by an hysteresis law and when used with the SIMetrix simulator the state change is controlled to occur over a fixed time period currently 10nS This device can be placed on a schematic with the menu PlacelAnalog Functions Switch with Hysteresis Chapter 5 Components Parameters are
456. y default but can be changed with SENSFILE option and they are also placed in a new data group The latter allows the data to be viewed in the message window type Display at the command line and can also be accessed from scripts for further analysis Setting up a Sensitivity Analysis Place a control of the following form in the F11 window SENS V nodename refnodename I sourcename nodename Output node to which sensitivities are calculated refnodename Reference node Ground if omitted sourcename Voltage source to measure output current to which sensitivities are calculated 197 User s Manual Simulator Options The simulator features a large number of option settings although fortunately the vast majority can be left at their default values for nearly all applications A few option settings can be set via the Choose Analysis dialog box and these are described in the following sections The remainder can be controlled using the simulator s OPTIONS control details of which may be found in the Simulator Reference Manual Setting Simulator Options 1 Select menu SimulatorlChoose Analysis 2 Select Options tab The following will be displayed 198 va yg joose Analysis Se Transient AC DC l Noise TF SOA Options Analysis Mode Transient Tolerances List file output Relati E Ac lative Fini 2 E Defaut Parameters Given tolerance N Curent _ Expand subcircuits tolerance Ip
457. y over the range specified by Start frequency Stop frequency and Number of points or Points per decade if you select a decade sweep You will also need to enter some additional parameters 53 User s Manual 54 Noise parameters upit node Use Terminal Ref node symbol to assign optional names for output and optional ref Source name pe optional An entry in the Output node box is compulsory It is the name of the circuit node as it appears in the netlist Usually the schematic s netlist generator chooses the node names but we recommend that when running a noise analysis that you assign a user defined name to your designated output node You can do this using a terminal symbol PlacelConnectors Terminal To find out more see Finding and Specifying Net Names on page 72 An entry in the Ref node box is optional It is the node to which the output node is referenced If omitted it is assumed to be ground An entry in the Source name box is optional If specified the noise referred back to it will be calculated Enter the component reference of the voltage or current source that is used as the input to your circuit Frequency sweep is just 1 of 6 modes available with Noise Analysis The Define button allows you to specify one of the others See Noise Analysis on page 189 for details DC Operating Point To specify a DC operating point analysis check the DCOP box on the right of the Choose Analysis Dialog
458. ymbol is a diagonal cross Repairing Missing Components If a component is missing you can either edit the schematic to identify the new location of the component or you can move files around so that the components are once again in the expected locations To edit the schematic select the place holder symbol then menu HierarchylReplace Component To relocate files use the system s file handling tools to move the component files then select menu HierarchylUpdate Symbols Highlighting The schematic highlighting features will work through a hierarchy The menus Edit Highlight by Net and Edit Highlight Net by Name will highlight a selected net within the displayed schematic and any connected nets in other schematics in the same hierarchy But note the following 1 In very large hierarchies it is possible that the mechanism that traces through the hierarchy to identify connected nets can noticeably slow down the time taken to descend into a new schematic Hierarchical highlighting can be disabled if this becomes a problem See menu File Options General then check Disabled under Hierarchy Highlighting 2 Connectivity information in SIMetrix schematics is normally only generated when a netlist is created For this reason it is possible for highlighting to be incomplete if a schematic has been edited since a simulation was last run The highlighting algorithms seeks to minimise this problem by running the netlister at c
459. ysis You will see this dialog box J Choose SIMPLIS Analysis x AC Transient Select analysis POP Triggering AC Use POP Trigger schematic device See menu Place gt Analog Functions gt POP Trigger Transient Tri ate giis Save options Trigger conditions Oto 1 1to0 5 All Voltages Only Conditions Probes Only Max period tu 8 Cycles before j launching POP E No Forced Output Dat E Force New Analysis Ok Run Cancel Help SIMPLIS offers three analysis modes namely Transient AC and Periodic Operating Point or POP These analysis modes are described in detail in the SIMPLIS Reference Manual The meaning of each of the controls is described in this chapter As with SIMetrix you can also enter the raw netlist command in the F11 window The contents of this window remain synchronised with the Choose Analysis dialog box settings so you can freely switch between the two methods Transient Analysis Chapter 8 SIMPLIS Analysis Modes SIMPLIS transient analysis is similar to S Metrix transient analysis Setting up a Transient Analysis 1 Select menu SimulatorlChoose Analysis 2 Select Transient check box on the right 3 Select Transient tab at the top Enter parameters as described in the following sections Analysis Parameters Stop Time Start Saving Data Plot data output Start plotting data The finish time of a transient analysis The data
460. ysis or PlacelCurrent Sources AC Source 47 User s Manual 48 You can also use a Universal Source see below for the AC source for SIMetrix i e not SIMPLIS simulations Be sure to check the Enable AC check box in the Universal Source Universal Source All of the sources described above can be used in both SIMetrix and SIMPLIS modes of operation In SIMetrix mode there is also a Universal source which provides the function of transient AC and DC sources all in one device In addition the Universal source may be used to create a random noise source To place a universal source select menu PlacelVoltage Sources Universal Source or PlacelCurrent Sources Universal Source To edit a universal source select the device and press F7 or popup menu Edit Part This will display the following dialog box Pulse Sine Noise Jac oc Tex V Enable DC Time Frequency Enable AC Period 100u S Frequency 10k a Spe Width 50u a Duty 505 a as Rise 500n S 7 Equal rise and fall Pie Fal 5 Sm ae 00n V Default rise and fall Tex Delay 0 o ji n None Repetitive Single Pulse Step Vertical Minimum 0 S Offset 500m 8 Maximum 1 Amplitude 1 a 7 Cancel Offset Minimum Pulse sine noise and DC waveforms may be specified using the tab sheets of the same name You can also specify a Piece wise linear source exponential source or a single frequency FM
461. ystems AC analysis finds the frequency response of a switching system without needing to use averaged models This is especially useful for what if studies on new circuit topologies or control schemes where the small signal averaged model has not yet been derived 17 User s Manual Because non linear devices are defined using a sequence of straight line segments models for such devices are quite different from SPICE models There are of course many SPICE models available and so in order to retain compatibility with these SIMetrix SIMPLIS has the ability to convert models for some types of device into SIMPLIS format This conversion is performed when the device is placed on the schematic Devices currently supported are MOSFETs BJTs and diodes In the case of MOSFETs and Zener diodes the conversion is achieved by performing a sequence of simulations using the SIMetrix SPICE simulator This method is independent of the method of implementation of the device Why Simulate 18 Integrated circuit designers have been using analog simulation software for over three decades The difficulty of bread boarding and high production engineering costs have made the use of such software essential For discrete designers the case has not been so clear cut For them prototyping is straightforward inexpensive and generally provides an accurate assessment of how the final production version of a circuit will behave By contrast computer simulation has
462. zoom just the x axis by dragging a horizontal line across an area outside any grid e g right at the bottom of the window below the lower x axis line To view whole graph again select the graph popup ZoomIFull or toolbar button Zooming with the Keyboard F12 to zoom out shift F12 to zoom in HOME returns graph to full view Same as graph popup ZoomIFull Recovering an Earlier Zoom Press the Undo Zoom toolbar button to recover earlier zoom or scroll positions Scrolling with the Keyboard up down left and right cursor keys will scroll the active graph Zooming with Multiple Grids Chapter 9 Graphs Probes and Data Analysis Each stacked grid is separated by a this grey line If when zooming you keep the zoom box within those lines only the vertical axis of that grid will be zoomed If you cross over a line the grid in which you cross will also be zoomed Adding new Curves to a Zoomed Graph If you add a new curve to a graph which has been zoomed the axes limits will not change to accommodate that curve if the new curve does not lie within the zoomed area you will not see it Selecting graph popup ZoomlFull or pressing HOME key restores the graph to auto scaling and the limits will always adjust so that all curves are visible even ones subsequently added Zoom to Fit Y axis To zoom in the y axis only to fit the displayed x axis press the Fit Height toolbar button Annotating a Graph A number of objects are availab

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