Datasheet LT1002 (Analog Devices) - 9
| Manufacturer | Analog Devices |
| Description | Dual, Matched Precision Operational Amplifier |
| Pages / Page | 16 / 9 — APPLICATIONS INFORMATION. Test Circuit for Offset Voltage. 0.1Hz to 10Hz … |
| File Format / Size | PDF / 188 Kb |
| Document Language | English |
APPLICATIONS INFORMATION. Test Circuit for Offset Voltage. 0.1Hz to 10Hz Noise Test Circuit. and its Drift with Temperature
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LT1002
U U W U APPLICATIONS INFORMATION Test Circuit for Offset Voltage 0.1Hz to 10Hz Noise Test Circuit and its Drift with Temperature
0.1µF 50k* 100k VOLTAGE GAIN = 50,000 15V PEAK TO PEAK NOISE MEASURED IN 10 SEC INTERVAL 10Ω – 3 – 14 (7) 2k A (10) + 1/2 13 (6) 22µF 1/2 LT1002 100Ω* V 4.3k SCOPE O LT1002 + B × 4 + 1 1/2 LT1002 RIN = 1MΩ (11) 12 (5) 4.7µF – DEVICE 50k* 2.2 UNDER µF * RESISTORS MUST HAVE LOW 100k –15V THERMOELECTRIC POTENTIAL. TEST 110k 0.1µF VO = 1000 VOS 24.3k 1002 TA05 1002 TA06 This circuit is also used as burn-in configuration for the The device under test should be warmed up for three LT1002, with supply voltages increased to ±20V. minutes and shielded from air currents. Turn the device 180° to measure the noise of side B. Unless proper care is exercised, thermocouple effects, caused by temperature gradients across dissimilar metals
Power supplies
at the contacts to the input terminals, can exceed the The LT1002 is specified over a wide range of power supply inherent drift of the amplifier. Air currents should be voltages from ±3V to ±18V. Operation with lower supplies minimized, package leads should be short, the two input is possible, down to ±1.2V (two Ni-Cad batteries). How- leads should be as close together as possible and main- ever, with ±1.2V supplies, the device is stable only in tained at the same temperature. closed loop gains of + 2 or higher (or inverting gain of one or higher).
Channel Separation
The V+ supply terminals are completely independent and may be powered by separate supplies if desired (this This parameter is defined as the ratio of the change in input approach, however, would sacrifice the advantages of the offset voltage of one amplifier to the change in output power supply rejection ratio matching). The V– supply voltage of the other amplifier causing the offset change. terminals are both connected to the common substrate and must be tied to the same voltage. Both V – pins should At low frequencies the LT1002’s channel separation is an be used. almost unmeasurable 148dB. As frequency increases, pin to pin capacitance of the package, between the output of one amplifier and the inputs of the other, becomes domi- nant. Since these pins are non-adjacent, the capacitance is only 0.02pF. To maintain the LT1002’s excellent channel separation at higher frequencies, the socket and PC board capacitances should be minimized. 1002fb 9
U U W U APPLICATIONS INFORMATION Test Circuit for Offset Voltage 0.1Hz to 10Hz Noise Test Circuit and its Drift with Temperature
0.1µF 50k* 100k VOLTAGE GAIN = 50,000 15V PEAK TO PEAK NOISE MEASURED IN 10 SEC INTERVAL 10Ω – 3 – 14 (7) 2k A (10) + 1/2 13 (6) 22µF 1/2 LT1002 100Ω* V 4.3k SCOPE O LT1002 + B × 4 + 1 1/2 LT1002 RIN = 1MΩ (11) 12 (5) 4.7µF – DEVICE 50k* 2.2 UNDER µF * RESISTORS MUST HAVE LOW 100k –15V THERMOELECTRIC POTENTIAL. TEST 110k 0.1µF VO = 1000 VOS 24.3k 1002 TA05 1002 TA06 This circuit is also used as burn-in configuration for the The device under test should be warmed up for three LT1002, with supply voltages increased to ±20V. minutes and shielded from air currents. Turn the device 180° to measure the noise of side B. Unless proper care is exercised, thermocouple effects, caused by temperature gradients across dissimilar metals
Power supplies
at the contacts to the input terminals, can exceed the The LT1002 is specified over a wide range of power supply inherent drift of the amplifier. Air currents should be voltages from ±3V to ±18V. Operation with lower supplies minimized, package leads should be short, the two input is possible, down to ±1.2V (two Ni-Cad batteries). How- leads should be as close together as possible and main- ever, with ±1.2V supplies, the device is stable only in tained at the same temperature. closed loop gains of + 2 or higher (or inverting gain of one or higher).
Channel Separation
The V+ supply terminals are completely independent and may be powered by separate supplies if desired (this This parameter is defined as the ratio of the change in input approach, however, would sacrifice the advantages of the offset voltage of one amplifier to the change in output power supply rejection ratio matching). The V– supply voltage of the other amplifier causing the offset change. terminals are both connected to the common substrate and must be tied to the same voltage. Both V – pins should At low frequencies the LT1002’s channel separation is an be used. almost unmeasurable 148dB. As frequency increases, pin to pin capacitance of the package, between the output of one amplifier and the inputs of the other, becomes domi- nant. Since these pins are non-adjacent, the capacitance is only 0.02pF. To maintain the LT1002’s excellent channel separation at higher frequencies, the socket and PC board capacitances should be minimized. 1002fb 9
