MAX1452KEY Datasheet
Contents
1. 2008 Maxim Integrated Products MAXIM is a registered trademark of Maxim Integrated Products Inc Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery amp Lifecycle Information Maxim Integrated 1452 MAX1455EVKIT NS2. MAX1455 EV Kit Bottom Silkscreen 55 EV BOARD REV C3 Figure 5 MAX1455 EV Kit Top Copper Figure 6 MAX1455 EV Kit Bottom Copper 8 MAXL MAX1455 Evaluation Kit 5 07 c ZVN4106F C8 6 R8 10 UN5214 06 05 UN RL2 LH HE207ND V 59 5214 gt gt R9 22kQ J3 o U4 11 MAX3387E Figure 7 MAX1452KEY Adapter Schematic Diagram MAKIL 9 1455 Evaluates MAX1455 Evaluation Kit Figure 8 Adapter Circuit PWB Top Silkscreen Figure 10 Adapter Circuit PWB Bottom Copper Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product No circuit patent licenses are implied Maxim reserves the right to change the circuitry and specifications without notice at any time 10 Maxim Integrated Products 120 San Gabriel Drive Sunnyvale CA 94086 408 737 7600
3. familiar with resistive element sensors and their com pensation techniques The purpose of the MAX1455EVKIT CS is to demonstrate the capabilities of the MAX1455 in compensating a typi cal resistive element sensor To assist the user in quickly evaluating the ASIC the board has been precompensat ed using a generic low pressure sensor such as the NovaSensor NPH8 100G In the case of the MAX1455EVKIT CS the test data print out included in the EV kit is specific to the particular EV board enclosed in the kit Both the test data and the EV board contain a serial number for identification Initial Setup See the MAX1455 EV board Figure 1 Four configura tion jumpers J1 J4 are provided to make the EV board adaptable to a wide range of applications J1 bypasses the VOUT isolation resistor and is not normally fitted J2 unlocks the MAX1455 digital interface and places the part in digital mode J3 connects DIO to VOUT for single pin programming J4 when fitted supplies power direct ly to the MAX1455 J4 must be removed when operating in digital mode as control of the power line is then provid ed by the serial adapter board Two rows of test points are provided to allow the user to probe the pins of the MAX1455 including the four sensor nodes If the user wishes to connect an alternative sensor this can be done using the 8 pin DIL socket S3 When connecting an alternative sensor the user must also cut the four split pad tracks S
4. type is digital mode 6 For analog mode make sure jumper J2 is removed and jumper J4 is present Note It is not possible to communicate with the MAX1455 while in analog mode 7 For digital mode make sure that jumper J2 is present and jumper J4 is removed before applying power to the EV board In addition make sure that the 10 pin ribbon cable connects the EV board to the serial com munication module and that the 9 pin connector on the serial module is connected to the PC either directly or through a straight connected serial cable MAX1455 EV Kit Contents The MAX1455EVKIT CS is shipped fully temp erature compensated from 40 C to 125 C The MAX1455EVKIT NS version of the EV kit is shipped without a sensor Additional material may be included in your EV kit which are not listed below MAX1455 EV board MAX1452KEY interface adapter e 10 ribbon cable for connecting the KEY and EV board e Computer interface adapter ribbon interconnect cable MAXIM MAX1455 Evaluation Kit e Printout of compensation test data MAX1455EVKIT CS only e Five samples of the MAX1455 Straight connected serial cable for connecting the KEY and PC Overview The objective of the EV kit is to allow the user to learn how to program the ASIC using a hands on approach To do this users are encouraged to compensate their own sensors using the EV kit along with the provided software This kit is intended to be used by engineers
5. 19 1032 0 5 08 General Description The MAX1455 evaluation kit EV kit demonstrates resis tive element sensor compensation and calibration using the MAX1455 and a computer The kit includes an assembled and tested PCB which is available with a factory calibrated sensor MAX1455EVKIT CS or with out a sensor MAX1455EVKIT NS The software and computer are not required for performing the initial per formance evaluation of the sensor option since the EV kit is already compensated A 10 pin ribbon cable nects the EV board to a serial key adapter MAX1452KEY that plugs into a computer serial port allowing the board to be evaluated inside an environ mental chamber The software requires a PC compati ble with Windows 95 98 2000 XP Windows is a registered trademark of Microsoft Corp DESCRIPTION C1 470uF 10V electrolytic capacitor C2 C4 C6 O 1uF X7R ceramic capacitors C3 C5 X7R ceramic capacitors 5 6V Zener diode Dual diode not installed 2 pin header not installed 2 pin header shorted 2 pin header 1 2 header shorted 2 pin header not installed 10 pin header 4mm banana sockets connect 45V GND OUT 100 5 resistor 4 7kQ 5 resistor 100 5 resistor 300 5 resistor NovaSensor Fremont NPH 8 100GH 8 pin TO package 100kPa gauge Unused alternate sensor site MAXKLM MAALMI MAX1455 Evaluation K
6. P1 SP4 that connect the resident sensor 51 52 These pads are located on the reverse side of the board The 10 way header P1 carries serial data and power to the serial adapter board This must be used when the MAX1455 is in digital mode and allows the user to reprogram the ASIC through the computer Three 4mm banana sockets P2 and P4 carry the 5V OUT and GND signals to the board Note that all the connectors and test pins are labeled on the board MAX1455 Evaluates MAX1455 Evaluation Kit Figure 1 Evaluation EV Board Layout Room Temperature Bench Test MAX1455EVKIT CS The board output is ratiometric to the supply and there fore a very accurate setting of the supply voltage is required to minimize measurement errors Also the board contains a Zener diode which helps protect against overvoltage and reverse voltage The protection circuit enables if the supply becomes less than approx imately 0 7V or more than approximately 5 6V The initial electrical connections should be made as follows 1 Connect the negative terminal of the power supply to the 4mm banana socket labeled GND 2 Connect the positive terminal of the power supply to the 4mm banana socket labeled 5V 3 Connect the DVM to the 4mm banana socket labeled OUT the ground return should be connect ed to the 4mm banana socket labeled GND IMPORTANT To avoid problems with ground loops noise
7. and to prevent possible damage to the MAX1452KEY adapter connect all equipment including the computer used later to the same AC circuit and use one common earth ground If the power supply has a programmable current limit set it to approximately 100mA Adjust the supply volt age to 5V and measure the voltage at test point VDD with respect to test point VSS At this point there should be no connection to the sensor pressure port Since the sensor supplied is a gauge type the output voltage at the analog connector should read about 0 5V Carefully remove the plastic sensor protector if sup plied and connect a silicone pressure tube to the sen sor pressure port Grasp the sensor not the PCB while fitting the tube in place Perform any required pressure controller initialization calibration procedures then vent the system The output voltage should read 0 5V Perform a few pressure cycles to minimize hys teresis effects Apply full scale pressure as stated in the test data or as written on the back of the board and confirm that the output reads 4 5V The user can also test at other lesser pressures to check for pressure lin earity errors Extended Temperature Pressure Test Additional equipment required Environmental chamber capable of 40 C to 125 C operation with a noncondensing atmosphere The unit can now be tested at any temperature in the 40 C 125 C range It is advisable to first perform one or t
8. d 5V return from serial board VDDOUT Switched 5 out to serial board GND Ground return screen 4 Ground return 5V power input 10 e Ground return D G Serial digital communications 10 ND Ground return MAKIN t Ki ion MAX1455 Evaluat Evaluates MAX1455 Id Zu3av3H MOL 9 old ano aNd 998 11000 NIGGA Nu2S NNO2 WW aNd Td NNOD WINY 11001010 r LNOdNV SSA 390 IND WNI 010 uag 1591 SSPLXVIA 61531 110 61531 1n0 o d 5 8141 NNOD WINY YOO INN e e ue N 10 55 4 8 100 Figure 2 MAX1455 EV Kit Schematic Diagram MAKLM MAX1455 Evaluates MAX1455 Evaluation Kit SUPPLY VOLTAGE 00 5 000 V ZI VI e PRESSURE RANGE 1 408 737 7600 GED o B SU C ras 31 0 1531 04 01 3L Ct ii 5V Figure 3 MAX1455 EV Kit Top Silk Figure 4
9. e PCB component placement and wiring information Replacing the Sensor MAX1455EVKIT CS The factory calibrated sensor can be replaced by a user provided sensor It is recommended to become fully familiarized with the basic operation of the ASIC MAXIM MAX1455 Evaluation Kit Table 1 Connector S3 Signals Sensor Interface Sia DESCRIPTION Positive output sensor Top of Wheatstone bridge Positive output sensor Bottom of Wheatstone bridge Negative sensor output Bottom of Wheatstone bridge OUT Negative sensor output and the software before attempting to remove the sen sor supplied with the board and replacing it with the user sensor The MAX1455 works with 4 wire closed Wheatstone bridge configured sensors An 8 pin DIL socket is provided for alternative sensor mounting The pinout for this connector is given in Table 1 Alternatively the user can test the ASIC using an artifi cial bridge consisting of four discrete resistors Some general knowledge of the user s sensor parameters must be known in order to set the initial coefficients This way the ASIC is not overloaded i e output satu rated It is recommended that the sensor wires be kept as short as possible to minimize system noise At this point refer to the Compensation Procedure section in the MAX1455 user manual for a step by step procedure for compensating the sensor Calibrate the new sensor in a temperature contro
10. ist continued 10V tantalum capacitor case Panasonic ECS T1AX106R DESIGNATION QTY DESCRIPTION npn transistors Panasonic UN5214 or UN5215CT Digi Key PCS2106CT ND equivalent capacitors 0805 urata GRM21BR71E104K or Switching diode 30V 0 2A O 1yF 10 25V ceramic pnp differential transistor Panasonic XP2401 n channnel MOSFET Zetex ZVN4106F 10 1W resistor 2512 Evaluates 110Q 1 8W resistors 1206 4700 1 8W resistor 1206 47kQ 1 8W resistors 1206 390kQ 1 8W resistor 1206 RB 10 1 8W resistor 1206 R9 R10 2 2 1 8W resistors 1206 Ultra reed relays Hamlin HE3621A0510 Digi Key HE207 ND Op amp SOT23 axim MAX4490AUK C hex inverter 14 SO Texas Instruments SN74HCO4DR Digi Key 296 1189 1 ND Quad 2 input 14 SO Texas Instruments SN74HCOODR Digi Key 296 1187 1 ND RS 232 5V driver receiver axim MAX3387ECUG AX1452KEY serial board PCB Indicates that part is normally consigned by Maxim Panasonic MA715 TX Digi Key MA715CT ND Diode BAR74 Zetex 747 pin headers gold 0 1in centers from 36 pin strip ins PZC36SAA i Key S1011 36 ND in header gold 0 1in center from 36 pin strip ullins PZC36SAA Ut igi Key 51011 36 hunts J1 open J2 shorted J3 02 ins 2 3 shorted lower two pins shorted ins SSCO24AN i Key S9002 ND Low profile header 2 x 5 0 1 centers 3M 2510 6002UB Digi Key MHB10K ND 9 pin D subc
11. it Features Proven PCB Layout Convenient On Board Test Points Fully Assembled and Tested Optional Pressure Sensor MAX1455EVKIT CS Factory Calibrated Over Temperature MAX1455EVKIT CS LabVIEW Based Software LabVIEW is a registered trademark of National Instruments Corp Ordering Information MAX1455EVKIT CS EV Kit MAX1455EVKIT NS EV Kit MAX1452KEY Serial Key Adapter MAX1452KEY is also used for MAX1455EVKIT and is included in MAX1455EVKIT package EV Kit Component List 8 pin DIL header alternate sensor connector Split pads cut tracks to allow connection of sensor at S3 Split pad configure on board op amp as buffer cut tracks to allow use of op amp MAX1455AA MAX1455AA KEY Component List DESCRIPTION 220uF 10V electrolytic capacitor radial lead Panasonic ECE A1AKA221 Digi Key P832 ND O 33uF 10 25V X7R ceramic capacitors 1206 Taiyo Yuden TMK316BJ334KF equivalent Murata GRM319R71E334K 0 047uF 10 50V X7R ceramic capacitor 1206 C1206C473K5RACTU Digi Key 399 1246 1 ND DESIGNATION QTY C2 C3 C5 Maxim Integrated Products 1 For pricing delivery and ordering information please contact Maxim Direct at 1 888 629 4642 or visit Maxim s website at www maxim ic com 1455 1455 Evaluation Kit DESIGNATION DESCRIPTION KEY Component L
12. lled environmental chamber Top of Wheatstone bridge EV Kit Software An unused serial port on the host PC is required to allow software control of the MAX1455 EV board The MAX1455 EV kit software is an executable file developed using National Instrument s LabVIEW soft ware LabVIEW application is not required to run the EV kit software The software is a high level interface that calls low level serial dll Note The MAX1455 software tools can be down loaded and installed from the Maxim website at www maxim ic com MAX1455 Evaluates MAX1455 Evaluation Kit MAX1455 EV Kit Files The software allows editing the contents of the ASIC s registers and EEPROM as well as observing the effects of changes to the DAC on the output Once desired results are obtained the EEPROM can be programmed with the register contents Consult the MAX1455 reference manual for a more complete description of software operation and usage Below is a listing of the main files included in the EV kit software tools MAX1455 EV Kit Files MAX1455 exe Communication program 55 Compensation program read me serial dll port98nt exe Optional file containing last minute additions Low level functional routines Device driver for PC IO communication Table 2 I O Connector Signal Digital Interface SIGNAL DESCRIPTION GND Ground return screen VDDIN Switche
13. ogical step after checking the module perfor mance is to actually edit and reprogram the module using the same sensor To do so configure the EV kit for digital operation and connect the digital interface to the computer first Below is a list of the computer requirements BM compatible PC e Windows 95 98 2000 XP e One unused serial port Detailed Hardware Description The MAX1455 U1 performs analog temperature com pensation on piezo resistive sensors The MAX1455 contains the temperature compensation coefficients in its internal EEPROM Figure 2 shows the circuit diagram of the EV board Figures 3 6 illustrate the PCB component placement and wiring details The MAX1455 has a single wire digital interface that can be connected to the output to maintain a true 3 wire sys tem The MAX1452KEY interface adapter converts and buffers the outputs from the computer serial port to com municate with the ASIC The adapter also controls power to the EV board when in digital mode This configuration allows power resets to be performed under software control The adapter operates internally at 5V The ratiometricity tests of the evaluation board should be limited to 4 5V to 5 5V while the digital connector is in place This requirement is to prevent logic level mismatch and the activation of any biasing protection diodes in the front end of the digital circuits Figure 7 shows the adapter circuit diagram and Figures 8 9 and 10 provid
14. onnector AMP 747905 2 Digi Key A2047 ND Power MOSFETs 8 pin SO 1 2 1 2 1 1 RL1 RL2 coU UW Fairchild NDS8958 Component Suppliers SUPPLIER PHONE 800 344 4539 864 963 6300 770 436 1300 626 333 5858 WEBSITE www digikey com www kemet com www murata northamerica com Digi Key Corp KEMET Corp Murata Electronics North America Inc Quest Components www questcomp com 2 MAXL WARNING NOT interconnect the EV board and the KEY while jumper J4 is in place as this will permanently damage the KEY when power is applied to the EV board Quick Start Required Equipment Precision regulated 5V power supply e Multimeter with at least five significant digits e Sensor pressure source Procedure Use the following quick start procedure to operate and evaluate the factory calibration accuracy of a MAX1455 EV board with sensor option 1 Download and install the MAX1455 EV kit software on your PC 2 Run Port98nt exe from the START menu or MAX1455 folder to load the device driver for PC IO communication 3 Connect a 5V power supply to the 5V and GND terminals on the EV kit 4 Connect a DVM between OUT and GND 5 Determine whether the EV board will run in analog or digital mode Factory setting of the CS type is analog mode Factory setting of the NS
15. wo full excursions of temperature and pressure to minimize hysteresis errors It is recommended that the electronics be conformal coated in any application where condensation of moisture might occur This was not done to the EV boards since the user might wish to modify the circuit for specific requirements Since the PCB is not conformal coated it is important that the environmental chamber not allow condensation to take place If this should happen a bake out at 125 C with no power applied for a minimum of 1hr is recommended Note that the circuit might behave errat ically if moisture is allowed to condense on the PCB since weak ionic paths affect some high impedance nodes on the board Most of the errors after compensation are due to the sen sor s drift and nonrepeatable behavior The EV board compensation printout includes the raw sensor output that was measured during compensation at each temperature Users might wish to compare this data with their measure ments of the sensor output in order to separate sensor errors from ASIC errors This can be performed at the sen sor connector To avoid attenuating the sensor output sig nal it is recommended to use a multimeter with an input impedance greater than 10 for this measurement Important Note Download factory compensated coef ficients into a file for future reference before overwrit ing flash content MAKLM Computer Requirements and Connections The next l
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