Datasheet

12OPA111
®
FIGURE 17. FET Input Instrumentation Amplifier.
6
2
3
OPA111
OPA111
Burr-Brown
INA105
Differential Amplifier
25kΩ 25kΩ
25kΩ
25kΩ
Output
6
5
1
3
2
+In
6
3
2
R
F
5kΩ
R
F
5kΩ
–In
R
G
101Ω
Differential Voltage Gain = 1 + 2R
F
/R
G
I
B
= 1pA
Gain = 100
CMRR ≈ 106dB
R
IN
= 10
13
Ω
FIGURE 18. Low-Droop Positive Peak Detector.
OPA111
2
3
6
Output
8
0.01µF
Polystyrene
IN914*
2N4117*
*Reverse polarity for
negative peak detection.
1MΩ
10kΩ
IN914*
≈10pF
3507J
2
3
6
8
30pF
Input
Droop ≈ 100µV/s