OP77_15 Datasheet, PDF (11/16 Pages) Analog Devices – Next Generation OP07 Ultralow Offset Voltage Operational Amplifier

OP77
APPLICATIONS
R2
1MΩ
+15V
0.1µF
R1
1kΩ
2
7
OP77E ⁶
3
R3
1kΩ
R4
4
0.1µF
1MΩ
–15V
Figure 27. Precision High-Gain Differential Amplifier
The high gain, gain linearity, CMRR, and low TCVOS of the
OP77 make it possible to obtain performance not previously
available in single-stage, very high-gain amplifier applications.
For best CMR, ^R1 must equal ^R3 . In this example, with a
R2
R4
10 mV differential signal, the maximum errors are as listed in
Table 7.
Table 7. Maximum Errors
Type
Common-Mode Voltage
Gain Linearity, Worst Case
TCVOS
TCIOS
R_F
10µF
+15V
0.1µF
R_S
INPUT
2
7
OP77 ⁶
3
4
0.1µF
Amount
0.01%/V
0.02%
0.003%/°C
0.008%/°C
100Ω
OUTPUT
C_LOAD
R3
+15V
V_IN
R1
R2
2
OP77 ⁶
3
2N2222
2N2907
R5
R4
–15V
( ) ^IOUT ^{= V}IN
R3
R1 – R5
GIVEN R3 = R4 + R5, R1 = R2
Figure 30. 100 mA Current Source
I_OUT < 100mA
These current sources can supply both positive and negative
current into a grounded load.
Note that
Z_O
=
R5_{⎜⎝⎛}
R4
R2
+ 1_{⎟⎠⎞}
R5 + R4 _R3
R2 R1
R5 + R4
And that for ZO to be infinite
must = ^R3
R2
R1
–15V
Figure 28. Isolating Large Capacitive Loads
This circuit reduces maximum slew rate but allows driving
capacitive loads of any size without instability. Because the boon
resistor is inside the feedback loop, its effect on output
impedance is reduced to insignificance by the high open-loop
gain of the OP77.
R3
1kΩ
R1
100kΩ
V_IN
R2
100kΩ
2
OP77 ⁶
3
R4
990Ω
I_OUT < 15mA
R5
10Ω
Figure 29. Basic Current Source
Rev. E | Page 11 of 16