OP27A, OP27C, OP27E, OP27G

OP37A, OP37C, OP37E, OP37G

LOW-NOISE HIGH-SPEED PRECISION OPERATIONAL AMPLIFIERS

SLOS100B – FEBRUARY 1989 – REVISED AUGUST 1994

2–19

POST OFFICE BOX 655303

POST OFFICE BOX 1443

APPLICATION INFORMATION

offset voltage and drift (continued)

The circuit shown in Figure 38 measures offset voltage. This circuit can also be used as the burn-in configuration

for the OP27 and OP37 with the supply voltage increased to 20 V, R1 = R3 = 10 k

Ω, R2 = 200 Ω, and

15 V

+

–

–15 V

R1

50 k

Ω

R2

100

Ω

R3

50 k

Ω

VO = 1000 VIO

2

3

6

7

4

NOTE A: Resistors must have low thermoelectric potential.

Figure 38. Test Circuit for Offset Voltage and Offset Voltage

Temperature Coefficient

unity gain buffer applications

is shown in the pulsed-operation diagram in Figure 39.

+

–

Rf

Output

2.8 V/

µs

OP27

Figure 39. Pulsed Operation

During the initial (fast-feedthrough-like) portion of the output waveform, 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

current

≤ 20 mA at 10 V), the amplifier stays in its active mode, and a smooth transition occurs. When