LT1007 Datasheet, PDF (17/24 Pages) Linear Technology – Low Noise, High Speed Precision Operational Amplifiers

LT1007, LT1007A, LT1037, LT1037A
LOW-NOISE, HIGH-SPEED, PRECISION OPERATIONAL AMPLIFIERS
SLOS017C – D3195, FEBRUARY 1989 – REVISED JANUARY 1993
APPLICATION INFORMATION
10 kΩ
VCC ₊
4.7 kΩ
1 kΩ
VCC ₊
4.7 kΩ
IN –
OUT
IN +
IN –
OUT
IN +
4
VCC _–
Figure 35. Standard Adjustment
VCC _–
Figure 36. Improved Sensitivity
Adjustment
The circuit shown in Figure 37 can be used to measure offset voltage. In addition, with the supply voltages
increased to ± 20 V, it can be used as the burn-in configuration for the LT1007 and LT1037.
When R_F ≤ 100 Ω and the input is driven with a fast large-signal pulse ( > 1 V), the output waveform will be as
shown in Figure 38.
During the fast-feedthrough-like portion of the output, the input protection diodes effectively short the output to
the input and a current, limited only by the output short-circuit protection, is drawn by the signal generator. When
R_F is ≥ 500 Ω, the output is capable of handling the current requirements (I_L ≤ 20 mA at 10 V), the amplifier stays
in its active mode, and a smooth transition occurs.
When R_F is > 2 kΩ, a pole will be created with R_F and the amplifier’s input capacitance, creating additional phase
shift and reducing the phase margin. A small capacitor (20 pF to 50 pF) in parallel with R_F will eliminate this
problem.
50 kΩ^†
15 V
100 Ω
VO
50 kΩ
– 15 V
VO = 1000 VOS
† _{Resistors must have low thermoelectric potential}
Figure 37. Test Circuit for Offset
Voltage and Offset Voltage Drift With
Temperature
RF
–
+
Output
2.8 V /µs
Figure 38. Pulse Operation
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