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The SR560 (manual - Stanford Research Systems

1. Integrated Circuit Thru hole Pkg Voltage Reg TO 220 TAB Package Voltage Reg TO 220 TAB Package Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Relay Voltage Reg TO 220 TAB Package Voltage Reg TO 220 TAB Package SRS sub assemblies SRS sub assemblies U 801 U 802 U 803 U 804 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 SR560 COMPONENT PARTS LIST 3 001 12 329 3 00307 340 3 00090 340 3 00250 340 0 00014 002 0 00017 002 0 00042 010 0 00043 011 0 00048 011 0 00077 030 0 00079 031 0 00089 033 0 00096 041 0 00109 050 0 00111 053 0 00122 053 0 00126 053 0 00128 053 0 00136 053 0 00153 057 0 00209 021 0 00231 043 0 00233 000 0 00237 016 0 00240 026 0 00242 026 0 00243 003 0 00249 021 0 00256 043 0 00259 021 0 00268 052 0 00284 025 0 00299 000 0 00312 000 0 00321 035 0 00322 035 0 00323 035 0 00324 035 0 00325 032 0 00327 050 0 00328 050 0 00329 050 0 00330 050 0 00333 052 0 00334 052 0 00350 053 0 00355 050 0 00466 050 0 00523 048 0 00524 048 7805 LM2940T 10 LF411 PS2501A 2 6J4 TRANSCOVER 4 40 HEX 4 40 KEP 6 32 KEP 3 16 X5 16 NYLN 4 40X3 16 M F 4 4 SPLIT 1 1 2 18 1 3 4 24B 2 1 4 24 3 1 2 24 4 24 8 1 2 24 GROMMET2 4 40X3 8PP 1 32 4 SHOULD HANDLE1 F1404 4 40X3 8PF 8 32X1 4P
2. First the front panel offset pot must be set to zero e Adjust front panel Offset pot to read 0 VDC on pin 14 U407 Next adjust the offset and CMRR for the case where the front end gain is x10 View the amplifier output on a scope and perform the following adjustments e Couple GND Gain 5 k LOW NOISE adjust P103 to null DC and output Now use a function generator as the source of a common mode signal 17 e Apply 1 kHz 1 Vpp sine to both the A and B inputs e Couple DC source A B adjust P102 to null sine wave output Now adjust the offset and CMRR for the case where the front end gain is x2 View the amplifier output on a scope and perform the following adjustments e Couple GND remove signal from A and B inputs Gain 5 k HIGH DR adjust P104 to null DC and output e Apply 1 kHz 1 Vpp sine to both the A and B inputs e Couple DC source A B adjust P101 to null sine wave output NOTE In the above procedures the gain of the front end x10 or x2 is determined by the selection of LOW NOISE or HIGH DYNAMIC RESERVE FRONT END REPLACEMENT The most commonly damaged component is the front end FET U106 National Semiconductor Corp P N NPD5564 It is located in an 8 pin DIP socket behind the relays near the input BNCs If the instrument exhibits a constant overload excessive drift or noise or large input bias currents it is likely that this component has been damaged When
3. NOISE SOURCES AND CURES Noise random and uncorrelated fluctuations of electronic signals finds its way into experiments in a variety of ways Good laboratory practice can reduce noise sources to a manageable level and the lock in technique can be used to recover signals which may still be buried in noise Intrinsic Noise Sources Johnson Noise Arising from fluctuations of electron density in a resistor at finite temperature these fluctuations give rise to a mean square noise voltage V 4KT Re Z f df 4 KTRAf where k Boltzmann s constant 1 38 x 10 J K T is the absolute temperature in Kelvin the real part ofthe impedance Re z f is the resistance R and we are looking at the noise source with a detector or AC voltmeter with a bandwidth of Af in Hz For a 1 MQ resistor V 12 0 13uV VHz To obtain the rms noise voltage that you would see across this 1MQ resistor we multiply 0 3 uV YHz by the square root of the detector bandwidth If for example we were looking at all frequencies between DC and 1 MHz we would expect to see a rms Johnson noise of V 12 0 134 V WHz 10 Hz 2 130 pV 1 f Noise Arising from resistance fluctuations in a current carrying resistor the mean squared noise voltage due to 1 f noise is given by V AR Af f where A is a dimensionless constant 10 for carbon R is the resistance the current the bandwidth of our detector and f is
4. This condition can occur when a signal is too large or the dynamic reserve is too low Reducing the gain reducing the input signal and or switching to the HIGH DYNAMIC RESERVE setting should remedy this condition If an overload occurs with filter settings of long time constants the RESET pushbutton will speed the SR560 s recovery from overload Status The ACT LED indicates communications activity over the SR560 s optoisolated RS 232 port Please refer to Appendix A Remote Programming for further details on programming the instrument via RS 232 The BLANK LED indicates the optoisolated BLANKING input on the rear panel of the SR560 is active The SR560 responds to a blanking input by internally grounding the amplifier signal path after the front end and before the first filter stage OPERATION AND CONTROLS I LINE FUSE 3 4A 100 120 VAC or 3 8A 220 240 VAC Nr Lue lt 200 mA ee 2 VOC a gt STATUS Figure 3 SR560 Rear Panel REAR PANEL OPERATING SUMMARY The SR560 rear panel is pictured in Figure 3 Various interface and power connectors are provided along with fuses and charger status LEDs AC Power Input The power entry module contains the receptacle for the AC line cord and fuse The line fuse should be a 1 A slow blow for 100 120 VAC operation or a 1 2 A slow blow for 220 240 VAC operation Amplifier Power Output The 12 V 12 V and AMP GROUND banana jack
5. 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Socket THRU HOLE Switch DIP Switch Panel Mount Power
6. 35V 20 Rad C 204 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 205 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 206 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 208 5 000 10 501 270P Capacitor Ceramic Disc 50V 10 SL C 209 5 00061 513 001U Capacitor Mylar Poly 50V 5 Rad C 210 5 00063 513 0033U Capacitor Mylar Poly 50V 5 Rad C211 5 00065 513 01U Capacitor Mylar Poly 50V 5 Rad C 212 5 00067 513 033U Capacitor Mylar Poly 50V 5 Rad C 213 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 214 5 00194 542 47U MIN Cap Mini Electrolytic 50V 20 Radial C 215 5 00194 542 47U MIN Cap Mini Electrolytic 50V 2096 Radial C 216 5 00193 542 2 2U MIN Cap Mini Electrolytic 50V 20 Radial C 217 5 00193 542 2 2U MIN Cap Mini Electrolytic 50V 20 Radial C 218 5 00213 546 4 7U Cap Mini Electro 100V 2096 Rad C 219 5 00213 546 4 7U Cap Mini Electro 100V 20 Rad C 220 5 00033 520 47U Capacitor Electrolytic 16V 20 Rad C 221 5 00033 520 47U Capacitor Electrolytic 16V 20 Rad C 222 5 00031 520 220U Capacitor Electrolytic 16V 20 Rad C 223 5 00031 520 220U Capacitor Electrolytic 16V 20 Rad C 224 5 00232 520 470U Capacitor Electrolytic 16V 20 Rad C 225 5 00232 520 470U Capacitor Electrolytic 16V 20 Rad C 226 5 00192 542 22U MIN Cap Mini Electrolytic 50V 20 Radial C 227 5 00192 542 22U MIN Cap Mini Electrolytic 50V 20 Radial C 228 5 00008 501 22P Capacit
7. 4 00301 408 4 00301 408 4 00619 408 4 00193 407 4 00528 408 4 00217 408 4 00544 407 4 00142 407 4 00203 407 4 00021 401 4 00215 407 4 00141 407 4 00192 407 4 00034 401 4 00142 407 4 00619 408 4 00142 407 4 00031 401 4 00528 408 4 00030 401 4 00030 401 4 00102 401 4 00030 401 4 00142 407 4 00030 401 4 00516 407 4 00164 407 4 00516 407 4 00168 407 4 00516 407 4 00168 407 4 00600 407 4 00168 407 4 00600 407 4 00600 407 4 00600 407 MTP20P06 MTPSNOS 49 9 100M 100M 10 10 10 10 249 150 100 1 000K 10 110 110 909 499 499 1 000K 165 100K 75 0K 1 0K 909 100 49 9K 10K 100K 909 100K 100 499 10 10 75K 10 100K 10 14 3K 20 0K 14 3K 22 6K 14 3K 22 6K 15 8K 22 6K 15 8K 15 8K 15 8K C 7 Voltage Reg TO 220 TAB Package Voltage Reg TO 220 TAB Package Resistor 2W 1 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 0 1 25ppm Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 0 1 25ppm Resistor Metal Film 1 8W 0 1 25ppm Resistor Metal Film 1 8W 0 1 25ppm Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 0 1 25ppm Resistor Metal Film 1 8W 0 1 25
8. C 812 C 813 C 814 C 815 C 816 C 817 C 818 C 819 C 820 C 821 C 822 C 823 C 824 C 825 C 826 C 827 C 828 C 829 C 830 C 831 C 832 D 101 D 201 D 202 D 301 D 302 D 401 D 402 D 403 D 404 D 405 D 406 D 407 D 408 D 501 D 502 D 503 D 505 D 701 D 702 D 703 D 704 SR560 COMPONENT PARTS LIST 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00023 529 5 00225 548 5 00023 529 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00225 548 5 00023 529 5 00100 517 5 00023 529 5 00023 529 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00023 529 5 00023 529 5 00023 529 3 00368 301 3 00368 301 3 00368 301 3 00368 301 3 00368 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00004 301 3 00226 301 3 00004 301 3 00226 301 3 00009 303 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U 1U AXIAL 1U 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL 1U 2 2U 1U 1U 2 2U 2 2U 2 2U 2 2U 2 2U 1U 1U 1U 1N753A 1N753A 1N753A 1N753A 1N753A 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N4148 1N5822 1N4148 1N5822 YELLOW C 5 Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor
9. Fuse Fuse Bracket Fabricated Part Printed Circuit Board Lexan Overlay Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Fabricated Part Shrink Tubing Product Labels Product Labels DESCRIPTION EPROM PROM 1 C Screw Black All Types Hardware Misc Hardware Misc Screw Panhead Phillips Hardware Misc Screw Black All Types Screw Panhead Phillips Screw Black All Types Fabricated Part Injection Molded Plastic Fabricated Part Fabricated Part SR560 COMPONENT PARTS LIST
10. When replacing the batteries take care to observe the polarities FUSE REPLACEMENT There are three fuses on the back panel of the instrument The fuse located inside the power entry module will blow if the unit draws excessive line current Replace this fuse with the value indicated for your line voltage CALIBRATION AND REPAIR The other two fuses are in line with the batteries These fuses will blow if the rear panel 12 VDC supplies are shorted or if the unit sources or draws excessive current to or from the batteries NOISE CONTOURS The noise contours shown below plot the noise figure as a function of source impedance and frequency Noise Figure NF is defined as e NF 20 log Output noise Gain X Source Thermal Noise A low noise figure means that the output noise is dominated by the thermal Johnson noise of the source A high noise figure indicates that the amplifier s output noise is dominated by the amplifier s own noise which is much larger than the thermal noise of the source The NF gets worse for low source resistances because the source s thermal noise gets very small while the amplifier s input voltage noise stays relatively constant The NF gets worse for low frequencies and low source resistances because the amplifier s 1 f noise is large relative to the thermal noise of the source The NF gets worse for large source impedances and high frequencies because the signal is attenuated he
11. which could occur if they were to remain connected to a load while dead The internal battery charging circuitry of the SR560 will automatically charge dead batteries at a quick rate until they are approximately 80 charged The charge rate is then lowered to a level that is safe for maintaining the batteries During AC operation the batteries will be in this maintain charge condition indefinitely and will suffer no degradation from prolonged charging The sealed lead acid batteries used in the SR560 differ in this respect from nickel cadmium batteries which do suffer shortened lifetimes due to overcharging The sealed lead acid batteries will provide the longest service life if they are not allowed to discharge too deeply and if they are charged immediately after use Battery Care WARNING As with all rechargeable batteries for safety reasons the chemical recombination processes within the cells require that the batteries be allowed to vent non corrosive gases to the atmosphere Always use the batteries in an area with adequate ventilation As with all instruments powered by rechargeable batteries the user must take some precautions to ensure long battery life Understanding and following the precautions outlined below will result in a long operating life for the batteries in the SR560 The SR560 s internal lead acid batteries will have a variable service life directly affected by THE NUMBER OF DISCHARGE CYCLES DEPTH
12. 17 3 00012 306 GREEN LED Rectangular D 18 3 00012 306 GREEN LED Rectangular D 19 3 00012 306 GREEN LED Rectangular D 20 3 00012 306 GREEN LED Rectangular D 21 3 00012 306 GREEN LED Rectangular D 22 3 00012 306 GREEN LED Rectangular D 23 3 00012 306 GREEN LED Rectangular D 24 3 00012 306 GREEN LED Rectangular D 25 3 00012 306 GREEN LED Rectangular D 26 3 00012 306 GREEN LED Rectangular D 27 3 00012 306 GREEN LED Rectangular D 28 3 00012 306 GREEN LED Rectangular D 29 3 00012 306 GREEN LED Rectangular D 30 3 00012 306 GREEN LED Rectangular D 31 3 00012 306 GREEN LED Rectangular D 32 3 00012 306 GREEN LED Rectangular D 33 3 00012 306 GREEN LED Rectangular D 34 3 00012 306 GREEN LED Rectangular D 35 3 00012 306 GREEN LED Rectangular D 36 3 00012 306 GREEN LED Rectangular D 37 3 00012 306 GREEN LED Rectangular D 38 3 00885 306 YELLOW LED Rectangular D 39 3 00885 306 YELLOW LED Rectangular D 40 3 00012 306 GREEN LED Rectangular D 41 3 00012 306 GREEN LED Rectangular D 42 3 00012 306 GREEN LED Rectangular D 43 3 00004 301 1N4148 Diode D 44 3 00004 301 1N4148 Diode D 45 3 00004 301 1N4148 Diode D 46 3 00004 301 1N4148 Diode D 47 3 00377 305 GL9ED2 LED Rectangular Bicolor C 1 D 48 J1 N 1 N2 N 3 NA N5 P 1 Q 1 Q 2 R1 R2 R3 R4 SW1 SW2 SW3 SW4 SW5 SW6 SW7 SW8 SW9 SW10 SW11 SW12 U 1 U2 U3 U5 Z0 SR560 COMPONENT PARTS LIST 3 00004 301 1 00035 130 4 00651 425 4 00651 425 4 00651
13. Capacitive Noise Coupling To estimate the noise current through Csiray into the detector we have Cstray dV JWCstray Vnoise t Where a reasonable approximation to Cstray can be made by treating it as parallel plate capacitor Here w is the radian frequency of the noise source perhaps 2 n 60 Hz Vnoise IS the noise voltage source amplitude perhaps 120 VAC For an area of A 0 01 m and a distance of d 0 1 m the capacitor will have a value of 0 009 pF and the resulting noise current will be 400 pA This meager current is about 4000 times larger than the most sensitive current scale that is available on the SR510 lock in Cures for capacitive coupling of noise signals include 1 Remove or turn off the interfering noise source 2 Measure voltages with low impedance sources and measure currents with high impedance sources to reduce the effect of stray 3 Install capacitive shielding by placing both the experiment and the detector in a metal box 60 Hz POWER CIRCUIT EXPERIMENT DETECTOR Inductive Noise Couplin Inductive Coupling Here noise couples to the experiment via a magnetic field A changing current in a nearby circuit gives rise to a changing magnetic field which induces an emf in the loop connecting the detector to the experiment emf d dt This is like a transformer with the experiment detector loop as the secondary winding Cures for inductively coupled noise i
14. Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Switch Momentary Push Button Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Printed Circuit Board DESCRIPTION Battery Battery Battery Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Mylar Poly 50V 5 Rad Capacitor Mylar Poly 50V 5 Rad Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL Capacitor Ceramic Disc 50V 10 SL SR560 COMPONENT PARTS LIST C 112 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 113 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 114 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 115 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 116 5 00005 501 150P Capacitor Ceramic Disc 50V 10 SL C 201 5 000 19 501 68P Capacitor Ceramic Disc 50V 10 SL C 202 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 203 5 00100 517 2 2U Capacitor Tantalum
15. PARTS LIST 4 00600 407 4 00600 407 4 00030 401 4 00165 407 4 00030 401 4 00325 407 4 00030 401 4 00030 401 4 00296 407 4 00165 407 4 00165 407 4 00140 407 4 00188 407 4 00158 407 4 00048 401 4 00048 401 4 00031 401 4 00305 401 4 00516 407 4 00164 407 4 00516 407 4 00168 407 4 00516 407 4 00168 407 4 00600 407 4 00168 407 4 00600 407 4 00600 407 4 00600 407 4 00030 401 4 00165 407 4 00030 401 4 00325 407 4 00030 401 4 00030 401 4 00296 407 4 00165 407 4 00165 407 4 00600 407 4 00600 407 4 00600 407 4 00705 407 4 00158 407 4 00048 401 4 00048 401 4 00030 401 4 00031 401 4 00065 401 4 00030 401 4 00030 401 15 8K 15 8K 10 200 10 845 10 10 604 200 200 10 2K 4 99K 2 00K 2 2K 2 2K 100 4 3K 14 3K 20 0K 14 3K 22 6K 14 3K 22 6K 15 8K 22 6K 15 8K 15 8K 15 8K 10 200 10 845 10 10 604 200 200 15 8K 15 8K 15 8K 5 62K 2 00K 2 2K 2 2K 10 100 3 3K 10 10 C 8 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Ca
16. Rocker Transformer U 101 U 102 U 103 U 104 U 105 U 106 U 201 U 202 U 203 U 204 U 205 U 301 U 302 U 303 U 304 U 305 U 401 U 402 U 403 U 404 U 405 U 406 U 407 U 408 U 409 U 501 U 502 U 503 U 505 U 506 U 507 U 508 U 509 U 510 U 601 U 602 U 603 U 604 U 605 U 606 U 607 U 701 U 702 U 703 U 704 U 705 U 706 U 707 U 708 U 709 SR560 COMPONENT PARTS LIST 3 00371 340 3 00382 340 3 00090 340 3 00385 340 3 00297 340 3 00246 340 3 00382 340 3 00270 340 3 00270 340 3 00189 340 3 00371 340 3 00270 340 3 00270 340 3 00189 340 3 00371 340 3 00382 340 3 00371 340 3 00297 340 3 00382 340 3 00090 340 3 00241 340 3 00383 340 3 00243 340 3 00143 340 3 00371 340 3 00155 340 3 00045 340 3 00298 340 3 00081 341 3 00039 340 3 00158 340 3 00049 340 3 00277 340 3 00259 340 3 00046 340 3 00046 340 3 00046 340 3 00046 340 3 00046 340 3 00046 340 3 00044 340 3 00384 329 3 00141 329 3 00067 340 3 00152 340 3 00239 335 3 00149 329 3 00141 329 8 00072 860 8 00072 860 DG444 OPA37 LF411 74HC4053 LT1028 NPD5564 OPA37 74HC4051 74HC4051 LF356 DG444 74HC4051 74HC4051 LF356 DG444 OPA37 DG444 LT1028 OPA37 LF411 AD7528JN LM6321 LM837 LM393 DG444 74HC04 74HC32 Z84C0008PEC 2KX8 100 74HC14 74HC154N 74HC74 74HC11 74HCT373 74HC374 74HC374 74HC374 74HC374 74HC374 74HC374 74HC244 LM350T LM337T CD4013 CD4051 HS 212 12 LM317T LM337T SR566 ASSY SR566 ASSY Integrated Ci
17. replacing the FET be certain that all eight pins are inserted into the socket and observe the orientation of pin 1 After replacement adjust the CMRR and offset per the calibration procedure More severely damaged front ends may require replacement of op amp U102 CALIBRATION AND REPAIR SR560 OFFSET ADJUSTMENT PROCEDURE Required equipment Digital volt meter Oscilloscope 4 BNC cables 1 BNC tee Function generator Small slotted screwdriver Phillips screwdriver Remove the bottom cover of SR560 to expose the component side of pc board 1 Turn off the SR560 Hold down the Reset button and turn the unit back on this sets the unit back to the default settings 2 Using a Digital Volt Meter adjust the front panel offset pot located between A and B input BNC s on front panel to read zero volts between pin 14 of U407 and ground output BNC shield Do not use the chassis as ground There are 4 potentiometers located on the bottom right side of the pc board Viewed from the component side with front panel facing forward These are P101 low gain CMRR adjust P102 high gain CMRR adjust P103 high gain offset adjust P104 low gain offset adjust 3 Set the SR560 coupling to GND and the gain 50 000 4 Connect the oscilloscope to the 50 Ohm output on the SR560 5 Adjust P103 for zero volts on the 50 ohm output using the oscilloscope 6 Set the SR560 gain 1000 and Source to A B 7 Set
18. signal and grounds the amplifier signal path after the front end for as long as the input is held high The response time of the blanking input is typically on 5 us after the rising edge and off 10 us after the falling edge RS 232 Interface The RS 232 interface connector allows listen only communication with the SR560 at 9600 baud DCE Communication parameters should be set to 8 bits no parity 2 stop bits Data sent must be delimited by lt CR gt lt LF gt All front panel functions excluding power and blanking are available over the RS 232 interface For more information on programming and commands see Appendix A Remote Programming BATTERY CARE AND USAGE The SR560 can be powered from either an AC power source or from three 12 V 1 9 Amp hour maintenance free sealed lead acid rechargeable batteries Integral to the SR560 is an automatic battery charger along with battery protection and charge indication circuitry Recharging During battery operation the front panel BATT LED will change from green to red to indicate that the batteries are low and require charging For the longest battery life the batteries should be immediately charged by plugging the unit into AC power whenever the BATT indicator lights red Internal protection circuitry will disconnect 11 the batteries from the amplifier if the unit is operated for too long in the low battery condition This protects the batteries from permanent damage
19. the frequency to which the detector is tuned For a carbon resistor carrying 10 mA with R 1k Af f 1 Hz we have Vnoise 3uVrms Others Other noise sources include flicker noise found in vacuum tubes and generation and recombination noise found in semiconductors All of these noise sources are incoherent Thus the total noise is the square root of the sum of the squares of all the incoherent noise sources Non Essential Noise Sources In addition to the intrinsic noise sources listed above there are a variety of non essential noise sources i e those noise sources which can be minimized with good laboratory practice It is worthwhile to look at what might be a typical noise spectrum encountered in the laboratory environment Power Line and Harmonics AM Broadcast TV 8 FM Stations Broadcasts Noise RADAR gt 1 f Background 60 Hz 1 MHz 100 MHz 1 GHz Frequency Noise Spectrum Some of the non essential noise sources appear in this spectrum as spikes on the intrinsic background There are several EXPERIMENT APPENDIX B ways which these noise sources work their way into an experiment Capacitive Coupling A voltage on a nearby piece of apparatus or operator can couple to a detector via a stray capacitance Although Cstray may be very small the coupled in noise may still be larger than a weak experimental signal STRAY CAPACITANCE 60 Hz POWER CIRCUIT DETECTOR
20. the function generator to square wave Freq 1 KHz amplitude 500mV pp 8 Using a BNC tee and 3 BNC cables put the square wave into channels A and B 9 Set the SR560 coupling to DC 10 Adjust P102 to null the square wave on the oscilloscope 18 11 Set the coupling to GND and gain 50 000 12 Readjust P103 for zero volts on the oscilloscope 13 Set SR560 gain 50 and coupling to DC 14 Set the oscilloscope to AC coupling 15 Using the digital volt meter measure the voltage from pin 6 of U105 to ground output BNC shield 16 Adjust P104 for zero volts on the meter 17 Adjust P101 to null the square wave on the oscilloscope You might have to readjust P104 and P101 several times The end result should be zero volts on pin 6 of U105 with the smallest amplitude square wave that you can achieve on the oscilloscope BATTERY REPLACEMENT After three to five years or about 1000 charge discharge cycles the sealed lead acid batteries degrade When the battery operation time shortens or if the unit stays very warm for more than a day after it is plugged into the line the batteries may require replacement The three batteries are a standard size which are available from several different distributors All are 12 VDC with a charge capacity of about 2 0 Amp hours and measure 7 02 X 1 33 X 2 38 Two of the batteries are wired in parallel to provide the high current required for the positive supply
21. 02 C 803 SR560 COMPONENT PARTS LIST 5 00033 520 5 00033 520 5 00031 520 5 00031 520 5 00232 520 5 00232 520 5 00023 529 5 00023 529 5 00192 542 5 00192 542 5 00100 517 5 00017 501 5 00100 517 5 00100 517 5 00100 517 5 00100 517 5 00021 501 5 00107 530 5 00100 517 5 00100 517 5 00100 517 5 00002 501 5 00100 517 5 00061 513 5 00061 513 5 00100 517 5 00023 529 5 00023 529 5 00023 529 5 00104 530 5 00233 532 5 00023 529 5 00023 529 5 00023 529 5 00234 551 5 00234 551 5 00100 517 5 00227 526 5 00227 526 5 00100 517 5 00023 529 5 00100 517 5 00100 517 5 00100 517 5 00023 529 5 00023 529 5 00262 548 5 00225 548 5 00225 548 5 00225 548 47U 47U 220U 220U 470U 470U 1U 1U 22U MIN 22U MIN 2 2U 47P 2 2U 2 2U 2 2U 2 2U 82P 1 8 6P 2 2U 2 2U 2 2U 100P 2 2U 001U 001U 2 2U 1U 1U 1U 3 5 20P 22P 1U 1U 1U 1000U 1000U 2 2U 100U 100U 2 2U 1U 2 2U 2 2U 2 2U 1U 1U 01U AXIAL 1U AXIAL 1U AXIAL 1U AXIAL C 4 Capacitor Electrolytic 16V 20 Rad Capacitor Electrolytic 16V 20 Rad Capacitor Electrolytic 16V 20 Rad Capacitor Electrolytic 16V 20 Rad Capacitor Electrolytic 16V 20 Rad Capacitor Electrolytic 16V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Mini Electrolytic 50V 20 Radial Cap Mini Electrolytic 50V 20 Radial Capacitor Tantalum 35V 20 Rad Capacitor Ceramic Disc 5
22. 0V 10 SL Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Ceramic Disc 50V 10 SL Capacitor Variable Misc Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Ceramic Disc 50V 10 SL Capacitor Tantalum 35V 20 Rad Capacitor Mylar Poly 50V 5 Rad Capacitor Mylar Poly 50V 5 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Variable Misc Capacitor Ceramic Disc 50V 10 NPO Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Electrolytic 35V 20 Ax Capacitor Electrolytic 35V 20 Ax Capacitor Tantalum 35V 20 Rad Capacitor Electrolytic 35V 20 Rad Capacitor Electrolytic 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX C 804 C 805 C 806 C 807 C 808 C 809 C 810 C 811
23. 15 R 716 R 717 R 718 R719 R 720 R721 R 722 R 723 R 724 R 725 R 726 R 727 R 728 R 729 R 730 R 731 R 801 R 802 R 803 R 804 R 805 R 806 R 807 R 808 R 809 R 810 R 811 R 812 R 813 R 814 R 815 R 816 R 817 SO102 SO106 SO504 SO708 SO709 SW601 SW801 T 1 SR560 COMPONENT PARTS LIST 4 00042 401 4 00376 407 4 00169 407 4 00058 401 4 00035 401 4 00035 401 4 00612 407 4 00278 407 4 00576 407 4 00386 407 4 00614 407 4 00613 407 4 00363 407 4 00383 407 4 00615 407 4 00207 407 4 00021 401 4 00032 401 4 00169 407 4 00169 407 4 00582 407 4 00582 407 4 00309 407 4 00022 401 4 00142 407 4 00031 401 4 00034 401 4 00034 401 4 00192 407 4 00192 407 4 00192 407 4 00155 407 4 00062 401 4 00056 401 4 00087 401 4 00063 401 4 00027 401 4 00094 401 4 00079 401 4 00142 407 4 00092 401 4 00022 401 1 00173 150 1 00173 150 1 00026 150 1 00570 150 1 00570 150 2 00008 207 2 00023 218 6 00067 610 15K 2 87K 249 220K 10M 10M 768K 10 7K 17 8K 30 9K 174K 147K 21 5K 12 7K 8 25K 806K 1 0K 100K 249 249 2 15K 2 15K 3 32K 1 0M 100K 100 10K 10K 49 9K 49 9K 49 9K 150K 270 22 510 3 0K 1 5K 6 8K 4 7K 100K 56K 1 0M 8 PIN MACH 8 PIN MACH 28 PIN 600 MIL 16 PIN 16 PIN SPSTX4 DPDT SR560 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film
24. 425 4 00336 425 4 00298 425 4 00611 452 3 00022 325 3 00021 325 4 00057 401 4 00059 401 4 00041 401 4 00081 401 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 2 00031 201 3 00303 340 3 00303 340 3 00303 340 3 00303 340 3 00303 340 7 00223 701 1N4148 20 PIN DIL 270X9 270X9 270X9 270X5 470X5 100K 2N3906 2N3904 220 22K 150 470 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 D6 01 05 74HC164 74HC164 74HC164 74HC164 74HC164 SR560 XX Main Board Parts List REF BT1 BT2 BT3 C 101 C 102 C 103 C 104 C 106 C 107 C 108 C 109 C 110 C 111 SRS part 6 00050 612 6 00050 612 6 00050 612 5 00098 517 5 00098 517 5 00098 517 5 00098 517 5 00069 513 5 00069 513 5 000 13 501 5 000 13 501 5 00159 501 5 000 19 501 VALUE GB1219 36 GB1219 36 GB1219 36 10U 10U 10U 10U 1U 1U 33P 33P 6 8P 68P C 2 Diode Connector Male Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Resistor Network SIP 1 4W 2 Common Pot Multi Turn Trim Mini Transistor TO 92 Package Transistor TO 92 Package Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Switch
25. 5 pF input impedance Their connector shields are completely isolated from chassis ground but can be made OPERATION AND CONTROLS common with chassis ground by connecting the AMP GROUND and CHASSIS GROUND banana jacks on the rear panel of the SR560 When connected to AC power the chassis of the unit is always connected to the grounding conductor of the AC power cord The inputs are protected to 100 VDC but the DC input should never exceed 10 Vp The maximum DC input before overload is 1 V peak The COUPLING pushbutton selects the method of connecting the A and B inputs to the amplifier The inputs can be AC 0 03 Hz 3 dB or DC coupled or the inputs to the amplifier can be internally grounded with the A and B input BNC s left floating This feature makes for simple offset nulling particularly useful when operating the amplifier DC coupled at high gains Please refer to CALIBRATION AND REPAIR OFFSET ADJUSTMENT for information on the offset nulling procedure NOTE When the coupling is set to AC a 0 03 Hz cutoff high pass filter is always engaged All high pass filter modes can still be selected while AC coupled but the 0 03 Hz filter will always be in even if the filters are set to DC Because one of the two filter sections is always used as a high pass when AC coupling is selected low pass filters are only available with a 6 dB octave rolloff The INVERT pushbutton allows the user to invert the output of the i
26. Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic 50V 80 20 Z5U AX Cap Monolythic Ceramic 50V 20 Z5U Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Capacitor Ceramic 50V 80 20 Z5U AX Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Capacitor Tantalum 35V 20 Rad Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Cap Monolythic Ceramic 50V 20 Z5U Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode Diode LED T1 Package D 705 D 706 D 707 D 708 D 709 D 710A D 710B D 711 D 801 D 802 D 803 J 101 J 102 J 404 J 405 J 601 J 805 JP801 K 101 K 102 K 103 K 104 K 105 K 201 K 301 N 701 N 702 P 101 P 102 P 103 P 104 P 701 P 702 Q 102 Q 103 Q 104 Q 105
27. DAC also provides the front panel uncal gain vernier function The sixth and final gain stage consists of U403 and output buffer U406 configured for a gain of 5 and with input attenuator U409 to select overall gains of 1 2 or 5 The LM6321 U406 provides the output drive capability for both the 600Q and 50Q outputs OVERLOAD DETECTION The overload detector constantly monitors the front end output filter 1 output U402 after the second filter output and final stage output for excessive signal levels Comparator U408 compares both positive and negative signal excursions against a 5 volt reference and lights the front panel overload indicator if any levels are excessive MICROPROCESSOR The system processor U503 is aCMOS Z80 processor running at 4 MHz The system clock consists of Schmitt trigger U506A and an R C network The oscillator is designed so that latch U508A can shut down the clock oscillator completely thereby disabling all digital circuits in the amplifier so that no digital noise will be present The processor and clock only run when a front 14 panel key is pressed and instrument settings are to be changed or while there is activity on the RS 232 port The SR560 uses a 16 K x 8 CMOS EPROM U504 containing system firmware and calibration bytes along with a 2 K x 8 CMOS RAM U505 which is battery backed up at all times to retain instrument settings U507 generates port strobes for system IO a
28. F TO 220 6 32X1 1 2PP 6 SHOULDER 4 40X1 2 PP 6 1 2 22 BL 10 32X1 2 1 8 ADHES TAPE FUSEHOLDER BLACK RED GREEN WHITE 2 520182 2 8 18 WHITE 8 18 RED 8 18 BLACK 5 1 2 18 6 22 1 3 4 22 2 1 4 24 20 18 RED 23 18 BLACK 5 5 8 18 8 1 4 18 Voltage Reg TO 220 TAB Package Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Power Entry Hardware Power Entry Hardware Nut Hex Nut Kep Nut Kep Spacer Standoff Tie Washer Split Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 24 UL1007 Strip 1 4x1 4 Tin Grommet Screw Panhead Phillips Washer nylon Hardware Misc Power Button Screw Black All Types Screw Black All Types Insulators Screw Panhead Phillips Washer nylon Screw Panhead Phillips Wire 22 UL1007 Screw Allen Head Hardware Misc Hardware Misc BANANA JACK BANANA JACK BANANA JACK BANANA JACK Termination Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 22 UL1007 Wire 22 UL1007 Wire 24 UL1007 Strip 1 4x1 4 Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1015 Strip 3 8 x 3 8 No Tin Wir
29. MODEL SR560 LOW NOISE PREAMPLIFIER S RS Stanford Research Systems 1290 D Reamwood Avenue Sunnyvale CA 94089 U S A 408 744 9040 Copyright 1989 1990 1997 1999 2011 2013 Stanford Research Systems All Rights Reserved Revision 3 0 8 2013 TABLE OF CONTENTS Introduction and Setup Instrument Overview Preparation for Use Line Voltage Line Fuse Line Cord Ventilation Power Up Repackaging for Shipment Use in Biomedical Applications Warning Regarding Use with Photomultipliers Accessories Furnished Environmental Conditions Symbols Specifications SR560 Low Noise Preamplifier Specifications Chart Operation and Controls Front Panel Operating Summary Power Source Filters Gain Mode Gain Output Reset Status Rear Panel Operating Summary AC Power Input Amplifier Power Output Battery Charger Blanking Input RS 232 Interface Battery Care and Usage Recharging Battery Care Circuit Description Differential Low Noise Front End Configurable Filters and Gain Output Stages Overload Detection Microprocessor Battery Charger and Pre regulators Power Regulators Rear Panel Interfaces Batteries and P E M Front Panel O O QN MNNMNNMNNMN gt on COODNOOOAONNN TABLE OF CONTENTS Calibration and Repair Offset Adjustment Calibration Front End Replacement SR560 Offset Adjustment Procedure Battery Replacement Fuse Replacement Noise Contours Input Voltage Noise Dynamic Reserve App
30. OF DISCHARGE AND AMBIENT TEMPERATURE The user should follow these simple guidelines below to ensure longest battery life OPERATION AND CONTROLS AVOID DEEP DISCHARGE Recharge the batteries after each use The two step fast charge trickle charge operation of the SR560 allows the charger to be left on indefinitely ALWAYS recharge the batteries immediately after the BATT indicator LED on the SR560 turns red Built in protection circuitry in the unit removes the batteries from the load once a dead battery condition is detected Avoiding deep discharge will provide the longest battery life upwards of 1 000 charge discharge cycles AVOID TEMPERATURE EXTREMES When using battery power operate the SR560 at or near room temperature Operating at lower temperatures will reduce the capacity of the batteries As well more time will be required to recharge the batteries to their rated capacity Higher temperatures accelerate the rate of reactions within the cell reducing cell life 12 KEEP THE BATTERIES COOL When not in use the SR560 should be stored in a cool dry place with the batteries fully charged This reduces the self discharge of the batteries and ensures that the unit will be ready for use when called upon A SR560 in storage should be topped off every three months with an overnight charge to maintain its batteries in peak condition Warning regarding battery maintenance Batteries used in this instrum
31. Q 106 Q 107 Q 108 Q 109 Q 110 Q 111 Q 201 Q 202 Q 301 Q 302 Q 501 Q 701 Q 702 SR560 COMPONENT PARTS LIST 3 0001 1 303 3 00062 340 3 00226 301 3 00226 301 3 00306 340 3 00391 301 3 00391 301 3 00198 301 3 00226 301 3 00004 301 3 00004 301 1 00073 120 1 00073 120 1 00073 120 1 00073 120 1 00035 130 1 00073 120 1 00016 160 3 00308 335 3 00308 335 3 00308 335 3 00308 335 3 00308 335 3 00308 335 3 00308 335 4 00497 421 4 00501 425 4 00353 441 4 00487 441 4 00617 441 4 00617 441 4 00011 441 4 00011 441 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00022 325 3 00021 325 3 003 10 329 3 00887 325 RED KBP201G BR 81D 1N5822 1N5822 LM385BZ 2 5 MBR360 MBR360 1N5231B 1N5822 1N4148 1N4148 INSL INSL INSL INSL 20 PIN DIL INSL RS232 25 PIN D DS2E ML2 DC5V DS2E ML2 DC5V DS2E ML2 DC5V DS2E ML2 DC5V DS2E ML2 DC5V DS2E ML2 DC5V DS2E ML2 DC5V 1 5KX4 1 0MX5 100 20 100K 100K 10K 10K 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3906 2N3904 MTP25N05 MPS2907A C 6 LED T1 Package Integrated Circuit Thru hole Pkg Diode Diode Integrated Circuit Thru hole Pkg Diode Diode Diode Diode Diode Diode Connector BNC Connector BNC Connector BNC Connector BNC Connecto
32. R 432 R 433 R 434 R 435 R 436 R 437 R 438 R 439 R 440 R 441 R 442 R 501 R 502 R 503 R 602 R 603 R 701 R 702 R 703 R 704 R 705 R 706 SR560 COMPONENT PARTS LIST 4 00325 407 4 00165 407 4 00030 401 4 00030 401 4 00030 401 4 00317 407 4 00296 407 4 00165 407 4 00165 407 4 00296 407 4 00165 407 4 00165 407 4 00555 407 4 00030 401 4 00030 401 4 00138 407 4 00188 407 4 00138 407 4 00186 407 4 00030 401 4 00186 407 4 00141 407 4 00021 401 4 00021 401 4 00021 401 4 00034 401 4 00021 401 4 00022 401 4 00022 401 4 00138 407 4 00138 407 4 00138 407 4 00138 407 4 00057 401 4 00616 453 4 00142 407 4 00142 407 4 00030 401 4 00021 401 4 00705 407 4 00027 401 4 00027 401 4 00142 407 4 00142 407 4 00142 407 4 00088 401 4 00142 407 4 00022 401 4 00169 407 4 00042 401 845 200 10 10 10 422 604 200 200 604 200 200 590 10 10 10 0K 4 99K 10 0K 4 22K 10 4 22K 100 1 0K 1 0K 1 0K 10K 1 0K 1 0M 1 0M 10 0K 10 0K 10 0K 10 0K 220 49 9 100K 100K 10 1 0K 5 62K 1 5K 1 5K 100K 100K 100K 51K 100K 1 0M 249 15K C 9 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM R
33. W601 accessible through the bottom cover of the unit positions 3 and 4 are placed in the off position All front panel functions can be controlled through the rear panel RS 232 interface Power The SR560 is turned on by depressing the POWER switch When disconnected from AC power the unit will operate for approximately 15 hours on internal sealed lead acid batteries Up to 200 mA of unregulated battery power is available at the rear panel banana jacks as long as the power switch is in the ON position Battery life will be reduced when the unit is providing external power through the rear panel jacks When operating on batteries the front panel BATT indicator will be lighted As the batteries near exhaustion this indicator will change from green to red indicating that the unit should be connected to AC power to charge the batteries When connected to an AC power source amplifier power is derived from regulated line power and the internal batteries are automatically charged When operating on AC power the front panel LINE indicator is on to indicate the source of amplifier power Charging status is indicated on the rear panel by the CHARGE and MAINTAIN LED indicators Source There are two input connectors located in the SOURCE section of the front panel The pushbutton located between them selects either single ended A or B or differential A B inputs The A and B inputs are voltage inputs with 100 MQ 2
34. ce allows calibration and control of the instrument at 9600 baud Data in and out on the connector are tied together echoing data back to the sender Hardware handshaking lines CTS DSR and CD are tied to DTR Refer to Appendix A 1 for information on remote programming of the SR560 CIRCUIT DESCRIPTION BATTERIES AND P E M The batteries used in the SR560 are of sealed lead acid construction There are three 12 V 1 9 amp hour batteries two of which serve as the positive power supply and one of which serves as the negative power supply Powering the SR560 alone battery life should be greater than 20 hours The batteries should last for more than 1000 charge discharge cycles provided the guidelines under the Usage section are followed Two 3A fast blow fuses on the rear panel protect the battery supplies and amplifier against excessive currents The power entry module P E M contains the AC line fuse RFI filter and voltage selection card To change the operating voltage of the unit the voltage selector printed circuit card must be pulled out and reinserted into the P E E M with the desired operating voltage visible 16 FRONT PANEL The front panel contains the keypad pushbuttons LED indicators and serial shift registers The front panel pushbuttons are decoded in a 3 x 4 matrix fashion The front panel LEDs are controlled by shift registers U1 through U5 which allow the 5 eight bit control bytes to be serially
35. d can be viewed as an in line BNC amplifier with the amplifier ground isolated from the chassis and the AC power supply Opto isolated input blanking control and listen only RS 232 interface lines are provided for instrument control Digital noise is eliminated by shutting down the microprocessor s oscillator except during the short time required to alter the instrument s configuration either through a front panel pushbutton or through an RS 232 command Internal sealed lead acid batteries provide 15 hours of line INTRODUCTION AND SETUP independent operation Rear panel banana jacks provide access to the internal regulated power supplies or batteries for use as a bias source PREPARATION FOR USE er CAUTIONS This instrument may be damaged if operated with the LINE VOLTAGE SELECTOR card set for the wrong applied AC input source voltage or if the wrong fuse is installed Line Voltage When the AC power cord is connected to the unit and plugged into an AC outlet the unit automatically switches the amplifier power source from internal battery operation to line operation The internal batteries are charged as long as AC power is connected The SR560 can operate from a 100 V 120 V 220 V or 240 V nominal AC power source having a line frequency of 50 or 60 Hz Before connecting the power cord to a power source verify that the LINE VOLTAGE SELECTOR card located in the rear panel fuse holder of the unit is set so that t
36. e 18 UL1015 Strip 3 8 x 3 8 No Tin Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 Z0 SR560 COMPONENT PARTS LIST 0 00666 050 0 00667 050 1 00124 178 1 00125 179 1 00126 176 1 00127 177 1 00128 171 4 00541 435 5 00027 503 6 00004 611 6 00074 611 7 00194 715 7 00201 720 7 00222 701 7 00232 709 7 00251 720 7 00252 720 7 00257 720 7 00258 720 7 00680 720 7 00795 720 7 007 96 720 9 00127 907 9 00267 917 9 00792 917 23 18 WHITE 20 18 WHITE 4 PIN 4 PIN 062 DIAM 062 DIAM 20 COND 130V 1200A 01U 1A 3AG 3A 3AG PS300 38 SR500 32 SR560 XX SR560 4 SR560 21 SR560 23 25 SR560 20 SR560 26 PS300 52 BATTERY PAN BATTERY RETAINR 1 2 CLEAR GENERIC EC WARNING Miscellaneous Parts List REF U 504 Z0 Z0 zo zo zo zo zo ZO Zo ZO Zo ZO SRS part 3 00305 342 0 00150 026 0 00179 000 0 00180 000 0 00185 021 0 00204 000 0 00248 026 0 00315 021 0 00326 026 7 00122 720 7 00217 735 7 00259 720 7 00260 720 VALUE 27C64 255 4 40X1 4PF RIGHT FOOT LEFT FOOT 6 32X3 8PP REAR FOOT 10 32X3 8TRUSSP 6 32X7 16 PP 8 32X1 4PP DG535 36 PS300 40 SR560 28 SR560 27 Wire 18 UL1007 Stripped 3 8x3 8 No Tin Wire 18 UL1007 Stripped 3 8x3 8 No Tin Connector Housing Plug Connector Housing Receptacle Terminal Male Terminal Female Cable Assembly Ribbon Varistor Zinc Oxide Nonlinear Resistor Capacitor Ceramic Disc 50V 20 Z5U
37. endix A Remote Programming Introduction Commands Appendix B Noise Sources and Cures Intrinsic Noise Sources Johnson Noise 1 f Noise Others Non Essential Noise Sources Capacitive Coupling Inductive Coupling Resistive Coupling Ground Loops Microphonics Thermocouple Effect SR560 Component List Front Panel Board Main Board Miscellaneous Parts PCB SR560 Revision F 9 89 Schematics uguuuUuUDUDDUUU dOoddrmponmoatbkeahih E 1 to E 10 INTRODUCTION AND SETUP Front End AC DC Coupling Amplifier Filter 1 HPF LPF N 0 03Hz 1MHz Signal Amplifier Filter 2 0 03Hz 1MHz HPF LPF N Output Amplifier Buffer Outputs 600 Microprocessor i System Blanking Input Optoisolated e Ext Power Power Supply y a Input Output Strobes amp Latche Optoisolated RS 232 Interface ES Amp Ground Batteries I J9 Chassis Ground Figure 1 SR560 Block Diagram INSTRUMENT OVERVIEW The SR560 architecture is diagrammed above The instrument provides DC coupled low noise amplification of single ended and true differential input signals at gains of 1 to 50 000 Two configurable R C filters are provided to selectively condition signals in the frequency range from DC to 1 MHz The user can choose high dynamic reserve or low noise settings and can invert the output relative to the input The SR560 normally operates with a fully floating ground an
38. ent are seal lead acid batteries With usage and time these batteries can leak Always use and store this instrument in the feet down position To prevent possible damage to the circuitboard it is recommended that the batteries be periodically inspected for any signs of leakage CIRCUIT DESCRIPTION DIFFERENTIAL LOW NOISE FRONT END Two high impedance inputs A and B allow the instrument to operate in either single ended or true differential modes Relays K103 and K104 allow the inputs A and B to be individually grounded while K101 selects AC or DC coupling Inversion of the inputs is provided by relay K105 The input capacitances and R101 and R102 establish the front end s input impedance at 25 pF and 100 MQ U106 is an NPD5564 low noise matched FET pair which along with U102 and U103 form the first differential amplifier stage U102 compares the currents in the drain loads of U106 and U103 maintains the sum of those currents at a fixed level by varying the total current in both FETs C109 provides open loop compensation for U102 and front end gain is nominally established by the sum of R118 and R112 over the sum of R114 and R128 K102 is a gain switching relay which selects a front end gain of 2 or 10 In the gain of 2 position gain to the next stage becomes 1 when R116 divides with the input attenuator to the next stage For a gain of 10 relay K102 shorts the top of R115 and R128 together essentially eliminating them fro
39. esistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor 2W 1 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 R 707 R 708 R 709 R 710 R 711 R 712 R 713 R 714 R 7
40. fier of this instrument is easily damaged if a photomultiplier is used improperly with the amplifier When left completely unterminated a cable connected to aPMT can charge to several hundred volts in a relatively short time Ifthis cable is connected to the inputs of the SR560 the stored charge may damage the front end FETs To avoid this problem provide a leakage path of about 100 kQ to ground inside the base of the PMT to prevent charge accumulation Accessories Furnished Power cable Operating Manual Environmental Conditions OPERATING Temperature 10 C to 40 C Relative Humidity lt 90 Non condensing NON OPERATING Temperature 25 C to 65 C Relative Humidity lt 95 Non condensing Warning regarding battery maintenance Batteries used in this instrument are seal lead acid batteries With usage and time these batteries can leak Always use and store this instrument in the feet down position To prevent possible damage to the circuitboard it is recommended that the batteries be periodically inspected for any signs of leakage Symbols you may find on SRS products Alternating current Caution risk of electric shock Frame or chassis terminal Caution refer to accompanying documents Earth ground terminal SPECIFICATIONS SR560 LOW NOISE PREAMPLIFIER SPECIFICATIONS CHART Inputs Impedance Maximum Inputs Maximum Output Noise CMRR Gain Flatness Gain Stability DC Drif
41. he correct AC input voltage value is visible Conversion from one AC input voltage to another requires a change in the fuse holder s LINE VOLTAGE SELECTOR card position and a new fuse Disconnect the power cord slide the fuse holder cover to the left and rotate the fuse pull lever to remove the fuse Remove the small printed circuit board Select the operating voltage by orienting the printed circuit board Press the circuit board firmly into its slot so the desired voltage is visible Rotate the fuse pull lever back into its normal position and insert the correct fuse into the fuse holder Line Fuse Verify that the correct line fuse is installed before connecting the line cord to the unit For 100 V and 120 V use a 1 Amp fuse and for 220 V and 240 V use a 1 2 Amp fuse Line Cord The SR560 has a detachable three wire power cord with a three contact plug for connection to both the power source and protective ground The protective ground connects to the accessible metal parts of the instrument except for BNC shields To prevent electrical shock always use a power source outlet that has a properly grounded protective ground contact Ventilation Always ensure adequate ventilation when operating the SR560 The unit will generate heat while charging dead batteries Power Up All instrument settings are stored in nonvolatile memory RAM backed up and are retained when the power is turned off They are not affected by
42. ill cause the cable capacitance to vary with time Since C Q V we have CdV V dC dQ i dt dt dt So mechanical vibrations will cause a dC dt which in turn gives rise to a current i which will affect the detector Ways to eliminate microphonic signals include 1 Eliminate mechanical vibrations 2 Tie down experimental cables so they will not sway to and fro 3 Use a low noise cable that is designed to reduce microphonic effects Thermocouple Effect The emf created by dissimilar metal junctions can give rise to many microvolts of DC potential and can be a source of AC noise if the temperature of the junction is not held constant This effect is large on the scale of many low level measurements APPENDIX B B 4 SR560 COMPONENT PARTS LIST Front Panel Parts List REF SRS part VALUE DESCRIPTION D1 3 00884 306 RED LED Rectangular D2 3 00012 306 GREEN LED Rectangular D3 3 00012 306 GREEN LED Rectangular D4 3 00012 306 GREEN LED Rectangular D5 3 00012 306 GREEN LED Rectangular D6 3 00012 306 GREEN LED Rectangular D7 3 00012 306 GREEN LED Rectangular D8 3 00012 306 GREEN LED Rectangular D9 3 00012 306 GREEN LED Rectangular D 10 3 00885 306 YELLOW LED Rectangular D11 3 00012 306 GREEN LED Rectangular D 12 3 00012 306 GREEN LED Rectangular D 13 3 00012 306 GREEN LED Rectangular D 14 3 00012 306 GREEN LED Rectangular D 15 3 00012 306 GREEN LED Rectangular D 16 3 00012 306 GREEN LED Rectangular D
43. level hysteresis is provided by R724 R731 and D711 provide un interrupted battery power to the system RAM so that stored instrument settings are retained when the power is switched off 15 POWER REGULATORS The 5 V and 10 V supplies are produced with three terminal regulators U801 and U802 respectively The 10 V supply is constructed of op amp U803 and Q801 a N channel MOSFET as the pass element The 10 V supply serves as the reference for the 10 V supply through divider R807 and R806 The power output banana jacks on the rear panel J801 and J803 are connected to the pre regulated voltages after the power switch and before the regulators This output can provide up to 200 mA of power for use as an external bias source etc Under some conditions these jacks may be used to supply the unit with external DC power U506D and U506B generate the TTL level input to the processor to indicate when the unit is operating on the AC line Capacitors C801 through C821 are logic supply bypass capacitors distributed throughout the printed circuit board REAR PANEL INTERFACES Two optically isolated rear panel interfaces are provided on the SR560 The blanking input accepts a TTL level signal and grounds the amplifier signal path after the front end for as long as the input is held high The response time of the blanking input is typically on 5 us after the rising edge and off 10 us after the falling edge The RS 232 interfa
44. lters and dynamic reserve setting The figure below shows the dynamic reserve and maximum input signal without overload for a SR560 set to a gain of 1000 the high pass filter set to 1 kHz and the low pass filter set to 10 kHz for a bandpass from 1 kHz to 10 kHz The dynamic reserve characteristic is shown for both High Dynamic Reserve and Low Noise gain modes There are several features to note In the bandpass region between 1 and 10 kHz the dynamic reserve is 0 dB The dynamic reserve is 3 dB at the filter frequencies of 1 and 10 kHz The dynamic reserve rises by 6 dB oct or 20 dB per decade as the signal moves away from the pole frequency since each RC filter attenuates the signal If a faster roll off for interfering signals were required a 12 dB octave HP or LP filter could be used The HIGH DR characteristic offers 16 dB more DR at low frequencies and 26 dB more at high frequencies The high frequency DR is limited only by the maximum 3 Vpp limit of the input stage The maximum DR in the low noise mode is 36 dB Since there is no gain between the HP and LP filters in the Low Noise gain mode the DR is the same at very high frequencies and very low frequencies The input reference voltage noise for the High DR gain mode is about 10 nV VHz compared to 4 nV VHz in the Low Noise gain mode The table middle of next page summarizes the input referenced noise and maximum dynamic reserve for all gains Dynamic Rese
45. m the gain loop P103 allows adjustment of front end offset and P104 allows for offset compensation when in the low gain configuration P102 allows adjustment of the front end common mode rejection ratio along with P101 which adjusts the CMRR in the low gain configuration In the second gain stage U105 is configured with a fixed gain of 10 By switching the input attenuation of this stage with DG444 U101 the overall gain of this stage can be computer selected as 2 5 or 10 C111 provides high frequency compensation for U105 The output of this stage passes through all three sections of U104 a CMOS multiplexer that serves as the blanking control The three parallel switches provide a low on resistance to 13 select either the output of the second stage amplifier or ground as the input to the next stage the first filter section CONFIGURABLE FILTERS AND GAIN The two filter stages in the SR560 each consist of 16 R C filters which can be configured as either high pass or low pass by a relay In the following description part references in parentheses refer to filter two Relay K201 K301 selects either the high pass or low pass configuration for all of the sixteen filters The output of one R C section is selected by multiplexer U202 or U203 U301 or U302 and passed on to non inverting buffer U202 U303 Approximately 80 pF input capacitance of the multiplexers is included in the calculation of the R C time consta
46. mmands The following commands are obeyed by all SR560 s that are addressed to listen The LALL LISN and UNLS commands are always obeyed and control the address status of the SR560 Commands must end with a carriage return and line feed lt CR gt lt LF gt BLINK i CPLGi DYNR i FLTM i Operates amplifier blanking i O not blanked 1 blanked Sets input coupling l 0 ground 1 DC 2 AC Sets dynamic reserve i 0 low noise 1 high DR 2 calibration gains defaults Sets filter mode i 0 bypass GAIN i HFROi INVT i LALL LISN i LFRQ i ROLD SRCE i UCAL i UCGN i UNLS RST 1 6 dB low pass 2 12 dB low pass 3 6 dB high pass 4 12 dB highpass 5 bandpass Sets the gain 0 14 1 2 5 50 k gain Sets highpass filter frequency 1 0 11 sets frequency 0 03 Hz to 10 kHz Sets the signal invert sense i 0 non inverted 1 inverted Listen all Makes all attached SR560 s listeners Listen command Makes SR560 with address i 0 1 2 3 a listener Sets lowpass filter frequency i 0 15 sets frequency 0 03 Hz to 1 MHz Resets overload for 1 2 second Sets the input source i 0 A 1 A B 2 B Sets the vernier gain status i O cal d gain 1 vernier gain Sets the vernier gain to i i 0 to 100 Unlisten Unaddresses all attached SR560 s Reset Recalls default settings APPENDIX A APPENDIX B
47. nce the gain reduced by the shunting capacitance of the input Under no circumstances will adding source resistance reduce the amplifier s output noise While this does improve the NF it does so by making the source so noisy that the amplifier is quiet in comparison SOURCE RESISTANCE IN OHMS AT 290K FREQUENCY IN Hz 19 SHORT CIRCUIT INPUT VOLTAGE NOISE IN nV JF7 CALIBRATION AND REPAIR INPUT VOLTAGE NOISE The amplifier s input voltage noise approximates that of a 10000 resistor about 4 nV VHz For source impedances below 10000 the output noise will be dominated by the amplifier s input voltage noise A typical amplifier has an input voltage noise vs frequency as shown in the figure below Notice that the voltage noise rises at lower frequencies 1 f noise 100Hz 1KHz DYNAMIC RESERVE The dynamic reserve of the amplifier is a measure of how large a signal can be present at the input to the amplifier without causing an overload condition The definition of dynamic reserve is e DR dB 20 log Vin f w o overload Vin for full scale A full scale output voltage is 10 Vpp Signals at the output or at any stage which exceed 10 Vpp cause an overload The dynamic reserve is greater than O dB only when the filters are used to remove unwanted signals The dynamic reserve is a function of frequency and depends on the amplifier 20 configuration gain fi
48. nclude 1 Remove or turn off the interfering noise source difficult to do if the noise is a broadcast station 2 Reduce the area of the pick up loop by using twisted pairs or coaxial cables or even twisting the 2 coaxial cables used in differential hookups 3 Use magnetic shielding to prevent the magnetic field from inducing an emf at high frequencies a simple metal enclosure is adequate 4 Measure currents not voltages from high impedance experiments APPENDIX B Resistive Coupling or Ground Loops Currents through common connections can give rise to noise voltages Resistive Couplin Here the detector is measuring the voltage across the experiment plus the voltage due to the noise current passing through the finite resistance of the ground bus This problem arises because we have used two different grounding points which are not at exactly the same potential Some cures for ground loop problems include 1 Ground everything to the same physical point 2 Use a heavier ground bus to reduce the potential drop along the ground bus 3 Remove sources of large currents from ground wires used for small signals Microphonics Microphonics provides a path for mechanical noise to appear as electrical noise in a circuit or experiment Consider the simple circuit below a LOCKAN AMPLIFIER B 3 The capacitance of a coaxial cable is a function of its geometry so mechanical vibrations w
49. nd U510 provides a buffered data bus The buffered data bus is active only during IO instructions to keep digital noise in the amplifier to a minimum while the processor is running U601 through U606 are control latches providing the 48 DC control lines that configure all of the instrument s hardware U607 is an input buffer and takes data from the front panel and RS 232 as well as providing a processor input indicating line operation and address from SW601 for ganged RS 232 operation SW601 additionally controls power to the front panel LED s through positions 3 and 4 BATTERY CHARGER AND PRE REGULATORS The 17 volt AC line transformer provides unregulated power for both amplifier operation and battery charging Diode bridge D706 and filter capacitors C706 and C707 generate unregulated DC that is pre regulated to 212 VDC by U706 and U707 to take the place of the batteries when the instrument is operating on AC line power Relay U705 switches the amplifier from battery to pre regulated AC whenever the AC line cord is plugged in Diode bridge D710 and C709 and C710 provide unregulated DC to charge the batteries U701 and U702 operates as AC regulators limiting peak battery charging voltage As there are two positive batteries and one negative battery U701 is a LM350 CIRCUIT DESCRIPTION regulator that provides twice the current of the LM317 negative battery regulator Charging is controlled by changing the set voltage of
50. nstrument with respect to the input when operating with single ended or differential inputs The INVERT LED displays the output sense relative to the input for all SOURCE settings Filters The SR560 contains two identical 1st order R C filters whose cutoff frequencies and topology high pass or low pass are controlled from the front panel The maximum bandwidth of the instrument is 1 MHz The filters in the FILTER CUTOFFS section can be configured in the following six ways i high pass filter at 12 dB octave ii high pass filter at 6 dB octave iii high pass filter at 6 dB octave and low pass filter at 6 dB octave band pass iv low pass filter at 6 dB octave v low pass filter at 12 dB octave vi no filters in the signal path The filter settings are controlled by the ROLLOFF HIGH PASS and LOW PASS pushbuttons Each time the ROLLOFF pushbutton is pressed the instrument configures the two R C filters to conform to the progression shown above The four ROLLOFF LED s give a visual indication of the current filter configuration For the HIGH PASS filter the left pushbutton serves to decrease its cutoff frequency The two pushbuttons for the LOW PASS filter function in an analogous manner When the FILTER CUTOFFS section is configured solely as high pass or low pass i ii iv and v the cutoff frequency is illuminated by one of sixteen LED s in the range from 0 03 Hz to 1 MHz and the slope of the r
51. nts of the filters The four highest frequency stages are not available as high pass filters because of unacceptable attenuation of the signal that occurs when the filter capacitance forms a divider with the input capacitance of the multiplexers DG444 U205D U401A is used to bypass the filter sections entirely and U101D U304D is used to reset the filter stages by discharging them through R228 R329 U201 U305 is the third fourth gain stage with a fixed gain of 5 The input attenuator U205 U304 allows setting the gain of these stages to 1 2 or 5 under computer control OUTPUT STAGES The fifth gain stage consists of op amp U402 which is configured as a non inverting amplifier with a gain of 5 U401 is a DG444 that again serves to switch the input attenuation of this stage for overall gains of 1 2 or 5 Additionally output offset CIRCUIT DESCRIPTION adjustment is provided by this stage U405B half of an AD7528 dual 8 bit DAC is used to provide a 5 volt offset voltage at the non inverting input of U402 The front panel offset control also sums at this junction and provides an offset voltage of 5 V that is buffered by U407D Following amplifier U402 is the other half of the 8 bit DAC U405A which along with op amp U404 forms a digital gain vernier This vernier is used in calibration to compensate for gain variances that occur with configuration changes such as input coupling and filter settings This
52. olloff is shown by one of the four ROLLOFF LED s When the filter section is configured as band pass iii the cutoff frequencies are illuminated by two LED s The frequency setting on the left marks the cutoff for the high pass filter and the setting on the right is the cutoff for the low pass filter The two 6 dB oct ROLLOFF LED s are also illuminated In this case the two cutoffs can be set to the same frequency to provide a narrow bandpass When both filters are removed from the signal path vi all rolloff and cutoff frequency LED s are extinguished from the FILTER CUTOFFS section and the DC LED is on NOTE High pass filters are not available for the four highest frequency settings See the note under Source Coupling for OPERATION AND CONTROLS information on using filters with the amplifier in AC coupled mode Gain Mode The allocation of gain throughout the instrument is set using the GAIN MODE pushbutton The Gain Mode is displayed by two indicator LED s HIGH DYNAMIC RESERVE and LOW NOISE For a given gain setting a HIGH DYNAMIC RESERVE allocates the SR560 s gain toward the output stages after the filters This prevents signals which are attenuated by the filters from overloading the amplifier The LOW NOISE setting allocates gain toward the front end in order to quickly lift low level nV range signals above the instrument s noise floor Gain The instrument s gain is increased or decreased using the GAIN pu
53. or Ceramic Disc 50V 10 SL C 230 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 301 5 00017 501 47P Capacitor Ceramic Disc 50V 10 SL C 302 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 303 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 304 5 00100 517 2 2U Capacitor Tantalum 35V 20 Rad C 306 5 00008 501 22P Capacitor Ceramic Disc 50V 10 SL C 307 5 00010 501 270P Capacitor Ceramic Disc 50V 10 SL C 308 5 00061 513 001U Capacitor Mylar Poly 50V 5 Rad C 309 5 00063 513 0033U Capacitor Mylar Poly 50V 5 Rad C 310 5 00065 513 01U Capacitor Mylar Poly 50V 5 Rad C 311 5 00067 513 033U Capacitor Mylar Poly 50V 5 Rad C 312 5 00023 529 1U Cap Monolythic Ceramic 50V 20 Z5U C 313 5 00194 542 47U MIN Cap Mini Electrolytic 50V 20 Radial C 314 5 00194 542 47U MIN Cap Mini Electrolytic 50V 20 Radial C 315 5 00193 542 2 2U MIN Cap Mini Electrolytic 50V 20 Radial C 316 5 00193 542 2 2U MIN Cap Mini Electrolytic 50V 20 Radial C 317 5 00213 546 4 7U Cap Mini Electro 100V 20 Rad C 318 5 00213 546 4 7U Cap Mini Electro 100V 20 Rad C 3 C 319 C 320 C 321 C 322 C 323 C 324 C 325 C 326 C 327 C 328 C 330 C 401 C 402 C 403 C 404 C 405 C 406 C 407 C 408 C 409 C 410 C 411 C 412 C 413 C 414 C 415 C 416 C 417 C 418 C 502 C 503 C 703 C 704 C 705 C 706 C 707 C 708 C 709 C 710 C 711 C712 C 713 C 714 C 715 C 716 C717 C718 C 801 C 8
54. ppm Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 0 1 25ppm Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 0 1 25ppm Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM R 212 R 213 R 214 R 215 R 216 R 217 R 218 R 219 R 220 R 221 R 222 R 223 R 224 R 225 R 226 R 227 R 228 R 229 R 301 R 302 R 303 R 304 R 305 R 306 R 307 R 308 R 309 R 310 R 311 R 312 R 313 R 314 R 315 R 316 R 317 R 318 R 319 R 320 R 321 R 322 R 323 R 324 R 325 R 326 R 327 R 328 R 329 R 330 R 401 R 402 SR560 COMPONENT
55. r Male Connector BNC Connector D Sub Right Angle PC Female Relay Relay Relay Relay Relay Relay Relay Res Network SIP 1 4W 2 Isolated Resistor Network SIP 1 4W 2 Common Pot Multi Turn Trim 3 8 Square Top Ad Pot Multi Turn Trim 3 8 Square Top Ad Pot Multi Turn Trim 3 8 Square Top Ad Pot Multi Turn Trim 3 8 Square Top Ad Pot Multi Turn Trim 3 8 Square Top Ad Pot Multi Turn Trim 3 8 Square Top Ad Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Transistor TO 92 Package Voltage Reg TO 220 TAB Package Transistor TO 92 Package Q 703 Q 801 R2 R 101 R 102 R 103 R 104 R 105 R 106 R 108 R 109 R 110 R 111 R 112 R 113 R 114 R 115 R 116 R 117 R 118 R 119 R 120 R 121 R 122 R 123 R 124 R 125 R 126 R 127 R 128 R 129 R 130 R 131 R 132 R 133 R 134 R 135 R 136 R 137 R 201 R 202 R 203 R 204 R 205 R 206 R 207 R 208 R 209 R 210 R 211 SR560 COMPONENT PARTS LIST 3 00374 329 3 00376 329 4 00616 453 4 00306 407 4 00306 407 4 00030 401 4 00030 401 4 00030 401 4 00030 401 4 00169 407 4 00041 401 4 00141 407 4 00217 408 4 00030 401
56. rbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Metal Film 1 8W 1 50PPM Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 Resistor Carbon Film 1 4W 5 R 403 R 404 R 405 R 406 R 407 R 408 R 409 R 410 R 411 R 412 R 413 R 415 R 416 R 417 R 418 R 419 R 420 R 421 R 422 R 423 R 424 R 425 R 426 R 427 R 428 R 429 R 430 R 431
57. rcuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit Integrated Circuit STATIC RAM I C Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg Thru hole Pkg A A A A A A A A A A A A A A A A A A A A A A A A A A NT A Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg Integrated Circuit Thru hole Pkg
58. rve dB CALIBRATION AND REPAIR Dynamic Reserve vs Frequency A 1000 BPF 1 kHz 10 kHz 1V 20 dB decade asen due 10 LPF poni 10 mV 1 10 100 1k 10k 100k 1M 10M Frequency Gain Input Noise Maximum nVN Hz DR dB 0 Gain Input Noise Maximum 1 60 0 nVN Hz DR dB 0 2 40 0 2000 LN 4 40 2000 HDR 10 52 5 25 6 5000 LN 4 48 10 LN 13 6 5000 MDR 8 54 10 HDR 25 14 10000 4 54 20 LN 11 6 20 HDR 25 20 20000 4 52 50 LN 10 14 50000 4 54 50 HDR 25 28 100 LN 4 14 100 HDR 20 34 200 LN 4 20 200 HDR 18 40 500 LN 4 28 500 HDR 15 48 1000 LN 4 34 1000 HDR 15 54 21 Maximum P P Input CALIBRATION AND REPAIR 22 APPENDIX A REMOTE PROGRAMMING Introduction The SR560 is equipped with a standard DB 25 RS 232C connector on the rear panel for remote control of all instrument functions The interface is configured as listen only 9600 baud DCE 8 bit no parity 2 stop bits and is optically isolated to prevent any noise or grounding problems Up to four SR560 amplifiers can be connected in parallel to the same RS 232 interface Units sharing the same interface must have a unique address as set on dip switch SW601 accessible through the bottom cover of the unit To set an instrument to one of the four available addresses adjust positions one and two of dip switch SW601 as follows SW601 Address Pos 2 Pos 1 of unit OFF OFF UNIT O OFF ON UNIT 1 ON OFF UNIT 2 ON ON UNIT 3 Co
59. s provide external DC power up to 200 mA for use as a bias source referenced to the amplifier s floating power supplies The CHASSIS GROUND banana jack is provided to allow the amplifier s ground to be referenced to the chassis Ifthe unit is connected to an AC power source via a three prong grounding plug the chassis 10 ground is connected to the AC line ground conductor Battery Charger The two 3 A slow blow fuses protect the battery supply and charging circuitry If these fuses are blown battery power will be unavailable and charging of the batteries will not be possible When both the positive and negative supply batteries are dead the red CHARGE LED will be on brightly and the batteries will be charging at a fast rate When the batteries approach a fully charged condition the charging current will be reduced to complete the charge and maintain the batteries Because the batteries charge at different rates the indicators on the rear panel can reflect the charge status of the positive and negative batteries independently When one set of batteries switches to the MAINTAIN mode the red CHARGE LED will be reduced to half brightness and the yellow MAINTAIN LED will turn on at half brightness When both batteries switch to MAINTAIN the red CHARGE LED will OPERATION AND CONTROLS turn off and the yellow MAINTAIN LED will be on full brightness Blanking Input The blanking input accepts a TTL level
60. shbuttons Gain settings from 1 to 50 000 are available and are displayed as the product of a factor 1 2 or 5 and a multiplier none i e 1 10 100 1 000 or 10 000 In addition to these fifteen fixed gain settings the user may specify arbitrary gains through the UNCAL feature To set an uncalibrated or arbitrary gain the User must press both Gain buttons simultaneously lighting the UNCAL LED In this mode by pressing the Gain Up or Gain Down pushbuttons the user may reduce the calibrated gain in roughly 1 increments from 100 down to 0 of the selected gain In contrast to other front panel functions when in UNCAL the instrument s key repeat rate will start slowly and increase to a limit as long as either Gain button is depressed Simultaneously pressing both Gain buttons once again will restore the unit to the previously calibrated gain setting and turn off the UNCAL LED Output The outputs of the instrument are located within the OUTPUT section of the front panel Two insulated BNCs are provided a 6000 output and a 50Q output The amplifier normally drives high impedance loads and the instrument s gain is calibrated for high impedance loads When driving a 6000 load via the 6000 output or a 50Q load via the 500 output the gain of the amplifier is reduced by two The shields of all the front panel BNC s are connected together and form the amplifier s floating ground Reset The OVLD LED indicates a signal overload
61. shifted in one bit ata time The red overload LED is controlled directly from the output of the overload comparator The battery LED is a dual color LED that is green when the unit is operating on battery power and turns red when the low_batt signal is asserted The front panel output offset pot P1 is also mounted on the front panel printed circuit board CALIBRATION AND REPAIR OFFSET ADJUSTMENT The SR560 s front panel offset adjustment provides an easy way for the user to null the amplifier s DC offset Use the COUPLING pushbutton to light the GND LED Now regardless of the SOURCE setting the input to the amplifier is grounded internally Insert a small screwdriver through the front panel OFFSET hole and adjust the offset potentiometer until the DC offset of the amplifier e g as viewed on a DVM is zero Finally return to the desired coupling CALIBRATION There are four pots which are used to calibrate the instrument The pots adjust the front end CMRR Common Mode Rejection Ratio and offset These pots are located close to the front of the instrument and may be accessed by removing the bottom cover These pots should be adjusted to optimize the CMRR or null the offset when the front end FET is replaced Two of the pots adjust the CMRR and offset when the front end gain is x10 and two adjust the CMRR and offset when the front end gain is x2 The x10 gain pots must be set first followed by the x2 gain pots
62. t Filters Distortion Power Battery Life Charge Time Mechanical Dimensions Warranty Single ended or true differential 100 MQ 25 pF DC coupled 1 VDC before overload 3 V peak to peak max AC coupled protected to 100 VDC 10 Vpp lt 4 nV VHz at 1 kHz gt 90 dB to 1 kHz decreasing by 6 dB octave 20 dB decade above 1 kHz 1 to 50 000 in 1 2 5 sequence vernier gain in 0 5 steps 0 3dB to 300kHz gains up to 1000 3 dB at 1 MHz 1 Vpp output 200 ppm C 5 uV C referred to input DC coupled 0 03 Hz to 1 MHz 10 typical accuracy 0 01 typical 100 120 220 240 VAC 50 60 Hz 60 Watts Max Internal Batteries 3 x 12 V 1 9 Ah sealed lead acid rechargeable 12 VDC in out through rear panel banana jacks 15 hours nominal 250 1000 charge discharge cycles 4 hours to 80 of capacity 1 2 Rack Mount width 3 1 2 height weight 15 lbs 14 7 8 x 8 1 8 x 3 1 2 1 year parts and labor on materials and workmanship SPECIFICATIONS OPERATION AND CONTROLS MODEL SRS60 LOW NOISE PREAMPLIFIER GAIN MODE HGH Low DYNAMIC RESERVE MOIS GAIN al0 Figure 2 SR560 Front Panel FRONT PANEL OPERATING SUMMARY The operation of the SR560 Low Noise Preamplifier has been designed to be as simple as possible The effect of each keypress on the front panel is reflected in the change of a nearby LED The front panel LED s will remain lighted at all times unless dip switch S
63. the regulators based on battery charge status Flip flop U703 determines whether the charge regulators will be set to 15 5 volts for a quick charge or 13 8 volts for a trickle or maintain charge by grounding the bottom of P701 and P702 C712 and R704 insure that the charger always powers up in the quick charge mode P701 and P702 are provided to adjust the open circuit trickle charge voltage to 13 8 volts D701 and D703 are blocking diodes for the charging circuits while not charging and D707 and D708 are clamps to guard against battery polarity reversal Comparators U708 and U709 are LP365 micropower comparators that monitor the battery voltage A resistive divider chain sets the four trip points for each comparator D709 provides a stable 2 5 volt reference against which levels are compared For each battery three level indications are provided and are decoded by multiplexer U704 The trip level is 14 5 volts The trip outputs control the state of U703 and switch the battery charge voltage settings The low level is 11 3 volts and activates the front panel low battery indicator R730 provides some level hysteresis for the low battery indication to prevent oscillation around the trip point The dead level is 10 7 volts and is used to disconnect the load from the batteries before they are damaged by an excessively deep discharge Q701 and Q703 are power MOSFET switches used to disconnect battery power from the amplifier Dead
64. the removal of the line cord If the power on self test passes the unit will return to the settings in effect when the power was last turned off If an error is detected or if the backup battery is exhausted the default settings will be used Additionally if he RESET key is held down when the power is turned on the instrument settings will be set to the defaults shown below Parameter Setting SOURCE Channel A COUPLING DC INVERT OFF INTRODUCTION AND SETUP ROLLOFF bypassed HIGH PASS 0 03 Hz 6 dB oct LOW PASS 1 MHz 6 dB oct GAIN MODE High Dynamic Reserve GAIN 20 calibrated LISTEN ON DEVICE ADDRESS As per SW601 Repackaging for Shipment The original packing materials should be saved for reshipment of the SR560 If the original packing materials are not available wrap the instrument in polyethylene sheeting or equivalent and place in a strong box cushioning it on all sides by at least three inches of high density foam or other filler material Use in Biomedical Applications Under certain conditions the SR560 may prove to be unsafe for applications involving human subjects Incorrect grounding component failure and excessive common mode input voltages are examples of conditions in which the instrument may expose the subject to large input currents Therefore Stanford Research Systems does not recommend the SR560 for such applications Warning Regarding Use with Photomultipliers The front end ampli

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