5962-8773802PA Datasheet, PDF (10/16 Pages) Analog Devices – Next Generation OP07 Ultralow Offset Voltage Operational Amplifier

OP77
TEST CIRCUITS
200kΩ
50Ω
OP77
V_O
V_OS
=
V_O
4000
Figure 21. Typical Offset Voltage Test Circuit
100Ω
100Ω
2.5MΩ
V+
2
7
OP77
3
4
6 ^3.3kΩ
4.7µF
OUTPUT
(≈10Hz FILTER)
V–
INPUT REFERRED NOISE = ^VO
25,000
Figure 22. Typical Low-Frequency Noise Test Circuit
–
INPUT
+
20kΩ
1
2
8
OP77 ^{7 6}
3
4
V+
OUTPUT
V–
Figure 23. Optional Offset Nulling Circuit
100kΩ
+18V
*
+
10µF
10Ω
10kΩ
2
0.1µF
7
OP77 ⁶
3
4
10kΩ
10Ω
0.1µF
* 10µF
+
–18V
NOTES
*1 PER BOARD
Figure 24. Burn-In Circuit
10kΩ
100kΩ
1MΩ
V_IN = ±10V
10Ω
TYPICAL PRECISION
OP AMP
V_Y
V_X
R_L
–10V
V_X
0V
+10V
NOTES
A_VO 650V/mV
R_L = 2kΩ
1. GAIN NOT CONSISTANT. CAUSES NONLINEAR ERRORS.
2. A_VO SPEC IS ONLY PART OF THE SOLUTION.
3. CHECK SPECIFICATION TABLE 1 AND TABLE 2 FOR PERFORMANCE.
Figure 25. Open-Loop Gain Linearity
Actual open-loop voltage gain can vary greatly at various output
voltages. All automated testers use endpoint testing and therefore
only show the average gain. This causes errors in high closed-
loop gain circuits. Because this is difficult for manufacturers to
test, users should make their own evaluations. This simple test
circuit makes it easy. An ideal op amp would show a horizontal
scope trace.
V_Y
–10V
0V
+10V
V_X
Figure 26. Output Gain Linearity Trace
This is the output gain linearity trace for the new OP77. The
output trace is virtually horizontal at all points, assuring
extremely high gain accuracy. The average open-loop gain is
truly impressive—approximately 10,000,000.
Rev. E | Page 10 of 16