SRS Labs SR560 manual

MODEL SR560 LOW-NOISE PR EAM PLIFI ER 1290-D Reamw ood Av enue Sunnyv ale, CA 94 089 U .S.A. (408) 7 44-9040 Copyr ight © 1989, 199 0, 1997, 1 999 Stanford Res earch Systems All Rights Reserved . Revi sion 2.8 (12/2006)[...]

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TABLE OF CONTENTS i Introduction and Setup Instrument Overview 1 Preparation for Use 2 Line Voltage 2 Line Fuse 2 Line Cord 2 Ventilation 2 Power-Up 2 Repackaging for Shipment 3 Use in Biomedical Applications 3 Warning Regarding Use with Photomultipliers 3 Accessories Furnished 3 Environmental Conditions 3 Symbols 4 Specifications SR560 Low Noise P[...]

TABLE OF CONTENTS ii Calibration and Repair Offset Adjustment 17 Calibration 17 Front End Replacement 17 SR560 Offset Adjustment Procedure 18 Battery Replacement 18 Fuse Replacement 18 Noise Contours 19 Input Voltage Noise 20 Dynamic Reserve 20 Appendix A Remote Programming A-1 Introduction A-1 Commands A-1 Appendix B Noise Sources and Cures B-1 In[...]

INTRODUCTION AND SETUP 1 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 r[...]

INTRODUCTION AND SETUP 2 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 **********CAUTION********* * This instrument may be damaged if operated with the LINE VOLTAGE SELECTOR card set for the wrong applied AC input source voltage or [...]

INTRODUCTION AND SETUP 3 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 i[...]

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SPECIFICATIONS 5 SR560 LOW-NOISE PREAMPLIFIER SPECIFICATIONS CHART Inputs Single-ended or true differential Impedance 100 M Ω + 25 pF, DC-coupled Maximum Inputs 1 VDC before overload; 3 V peak to peak max AC coupled; protected to 100 VDC Maximum Output 10 Vpp Noise <4 nV/ √ Hz at 1 kHz CMRR >90 dB to 1 kHz, decreasing by 6 dB / octave (20[...]

SPECIFICATIONS 6[...]

OPERATION AND CONTROLS 7 Figure 2: SR560 Front Panel FRONT PANEL OPER ATING 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 SW6[...]

OPERATION AND CONTROLS 8 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 [...]

OPERATION AND CONTROLS 9 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&ap[...]

OPERATION AND CONTROLS 10 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[...]

OPERATION AND CONTROLS 11 turn off and the yellow "MAINTAIN" LED will be on full brightness. Blanking Input 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 µs after the risin[...]

OPERATION AND CONTROLS 12 • 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[...]

CIRCUIT DESCRIPTION 13 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 ca[...]

CIRCUIT DESCRIPTION 14 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[...]

CIRCUIT DESCRIPTION 15 regulator that provides twice the current of the LM317 negative battery regulator. Charging is controlled by changing the set voltage of 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 "maint[...]

CIRCUIT DESCRIPTION 16 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 s[...]

CALIBRATION AND REPAIR 17 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-[...]

CALIBRATION AND REPAIR 18 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 th[...]

CALIBRATION AND REPAIR 19 The other two fuses are in-line with the batte ries . The se fuse s w ill blow i f the rea r panel ± 12 VDC supplies are shorted, or if the unit sources or draws ex cessive current to o r fro m the ba tteri es. NOISE CONTOURS The noise contours (show n upper right) plot the noise figure as a function of source impedance a[...]

CALIBRATION AND REPAIR 20 INPUT VOLTAGE NOISE The amplifier's input voltage noise approximates that of a 1000 Ω resistor (about 4 nV/ √ Hz). For source impedances below 1000 Ω , 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 figu[...]

CALIBRATION AND REPAIR 21 Gain Input Noise (nV/ √ Hz ) Maximum DR (dB 0) 1 60 0 2 40 0 5 25 6 10, LN 13 6 10, HDR 25 14 20, LN 11 6 20, HDR 25 20 50, LN 10 14 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 Gain Input Noise (nV/ √ Hz ) Maximum DR (dB 0) 2000, LN 4 4[...]

CALIBRATION AND REPAIR 22[...]

APPENDIX A A - 1 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 S[...]

APPENDIX A A - 2[...]

APPENDIX B B - 1 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 Source[...]

APPENDIX B B-2 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 C stray may be very small, the coupled in noise may still be larger than a weak experimental signal. Capacitive Noise Coupling To estim[...]

APPENDIX B B-3 Resistive Coupling (or ‘Ground Loops’) Currents through common connections can give rise to noise voltages. Resistive Coupling 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 us[...]

APPENDIX B B-4[...]

SR560 COMPONENT PARTS LIST C-1 Front Panel Parts List REF. SRS part# VALUE DESCRIPTION D 1 3-00884-306 RED LED, Rectangular D 2 3-00012-306 GREEN LED, Rectangular D 3 3-00012-306 GREEN LED, Rectangular D 4 3-00012-306 GREEN LED, Rectangular D 5 3-00012-306 GREEN LED, Rectangular D 6 3-00012-306 GREEN LED, Rectangular D 7 3-00012-306 GREEN LED, Rect[...]

SR560 COMPONENT PARTS LIST C-2 D 48 3-00004-301 1N4148 Diode J 1 1-00035-130 20 PIN DIL Connector, Male N 1 4-00651-425 270X9 Resi stor Network SIP 1/4W 2% (Common) N 2 4-00651-425 270X9 Resi stor Network SIP 1/4W 2% (Common) N 3 4-00651-425 270X9 Resi stor Network SIP 1/4W 2% (Common) N 4 4-00336-425 270X5 Resi stor Network SIP 1/4W 2% (Common) N [...]

SR560 COMPONENT PARTS LIST C-3 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, Ce ramic Disc, 50V, 10%, SL C 201 5-00019-501 68P [...]

SR560 COMPONENT PARTS LIST C-4 C 319 5-00033-520 47U Capacitor, Electrolytic, 16V, 20%, Rad C 320 5-00033-520 47U Capacitor, Electrolytic, 16V, 20%, Rad C 321 5-00031-520 220U Capacito r, Electrolytic, 16V, 20%, Rad C 322 5-00031-520 220U Capacito r, Electrolytic, 16V, 20%, Rad C 323 5-00232-520 470U Capacito r, Electrolytic, 16V, 20%, Rad C 324 5-[...]

SR560 COMPONENT PARTS LIST C-5 C 804 5-00225-548 .1U AXIAL Capacitor, Cerami c, 50V,+80/-20% Z5U AX C 805 5-00225-548 .1U AXIAL Capacitor, Cerami c, 50V,+80/-20% Z5U AX C 806 5-00225-548 .1U AXIAL Capacitor, Cerami c, 50V,+80/-20% Z5U AX C 807 5-00225-548 .1U AXIAL Capacitor, Cerami c, 50V,+80/-20% Z5U AX C 808 5-00023-529 .1U Cap, Monolythic Ceram[...]

SR560 COMPONENT PARTS LIST C-6 D 705 3-00011-303 RED LED, T1 Package D 706 3-00062-340 KBP201G/BR-81D Integrat ed Circuit (Thru-hole Pkg) D 707 3-00226-301 1N5822 Diode D 708 3-00226-301 1N5822 Diode D 709 3-00306-340 LM385BZ-2.5 Integrated Circuit (Thru-hole Pkg) D 710A 3-00 391-301 MBR360 Diode D 710B 3-00 391-301 MBR360 Diode D 711 3-00198-301 1[...]

SR560 COMPONENT PARTS LIST C-7 Q 703 3-00374-329 MTP20P06 Voltage Reg., TO-220 (TAB) Package Q 801 3-00376-329 MTP5N05 Voltage Reg., TO-220 (TAB) Package R 2 4-00616-453 49.9 Resistor, 2W, 1% R 101 4-00306-407 100M Resistor, Metal Film, 1/8W, 1%, 50PPM R 102 4-00306-407 100M Resistor, Metal Film, 1/8W, 1%, 50PPM R 103 4-00030-401 10 Resistor, Carbo[...]

SR560 COMPONENT PARTS LIST C-8 R 212 4-00600-40 7 15.8K Res istor, Meta l Film , 1/8W , 1%, 50PPM R 213 4-00600-40 7 15.8K Res istor, Meta l Film , 1/8W , 1%, 50PPM R 214 4-00030-40 1 10 Resistor , Carbon F ilm , 1/4W , 5% R 215 4-00165-40 7 200 Resist or, Meta l Film , 1/8W , 1%, 50PPM R 216 4-00030-40 1 10 Resistor , Carbon F ilm , 1/4W , 5% R 21[...]

SR560 COMPONENT PARTS LIST C-9 R 403 4-00325-40 7 845 Resist or, Meta l Film , 1/8W , 1%, 50PPM R 404 4-00165-40 7 200 Resist or, Meta l Film , 1/8W , 1%, 50PPM R 405 4-00030-40 1 10 Resistor , Carbon F ilm , 1/4W , 5% R 406 4-00030-40 1 10 Resistor , Carbon F ilm , 1/4W , 5% R 407 4-00030-40 1 10 Resistor , Carbon F ilm , 1/4W , 5% R 408 4-00317-4[...]

SR560 COMPONENT PARTS LIST C-10 R 707 4-00042-401 15K Resistor, Carbon Film, 1/4W, 5% R 708 4-00376-407 2.87K Resistor, Metal Film, 1/8W, 1%, 50PPM R 709 4-00169-407 249 Resistor, Metal Film, 1/8W, 1%, 50PPM R 710 4-00058-401 220K Resistor, Ca rbon Film, 1/4W, 5% R 711 4-00035-401 10M Resistor, Carbon Film, 1/4 W, 5% R 712 4-00035-401 10M Resistor,[...]

SR560 COMPONENT PARTS LIST C-11 U 101 3-00371-340 DG444 Integrated Circuit (Thru-hole Pkg) U 102 3-00382-340 OPA37 Integrated Circuit (Thru-hole Pkg) U 103 3-00090-340 LF411 Integrated Circuit (Thru-hole Pkg) U 104 3-00385-340 74HC4053 Integrated Circuit (Thru-hole Pkg) U 105 3-00297-340 LT1028 Integrated Circuit (Thru-hole Pkg) U 106 3-00246-340 N[...]

SR560 COMPONENT PARTS LIST C-12 U 801 3-00112-329 7805 Voltage Reg., TO-220 (TAB) Package U 802 3-00307-340 LM2940T-10 Integrated Circuit (Th ru-hole Pkg) U 803 3-00090-340 LF411 Integrated Circuit (Thru-hole Pkg) U 804 3-00250-340 PS2501A-2 Integrated Circuit (Thru-hole Pkg) Z 0 0-00014-002 6J4 Power Entr y Hardware Z 0 0-00017-002 TRANSCOVER Powe[...]

SR560 COMPONENT PARTS LIST C-13 Z 0 0-00666-050 23" #18 WHITE Wire #18 UL1007 Stripped 3/8x3/8 No Tin Z 0 0-00667-050 20" #18 WHITE Wire #18 UL1007 Stripped 3/8x3/8 No Tin Z 0 1-00124-178 4 PIN Connector Housing, Plug Z 0 1-00125-179 4 PIN Connector Housing, Rece ptacle Z 0 1-00126-176 .062" DIAM Terminal, Male Z 0 1-00127-177 .062&q[...]

SR560 COMPONENT PARTS LIST C-14[...]