Datasheet

Typical single-supply applications LM2902
12/21 Doc ID 2469 Rev 7
Figure 25. High input Z, DC differential
amplifier
Figure 26. Low drift peak detector
Figure 27. Using symmetrical amplifiers to
reduce input current (general
concept)
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LM2902
R1
100 k
Ω
R2
100 k
Ω
R4
100 k
Ω
R3
100 k
Ω
+V2
+V1
V
o
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LM2902
eo = [ 1 + ] (e2 - e1)
As shown eo = (e2 - e1)
R4
R3
I
B
2N 929
0.00 1 μF
I
B
3R
3 M
Ω
I
B
Inputcurrent
compensation
e
o
I
B
e
I
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LM2902
Z
o
Z
I
C
1 μF
2I
B
R
1 M
Ω
2I
B
* Polycarbonate or polyethylene
*
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LM2902
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LM2902
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LM2902
I
B
2N 929
0.001 μF
I
B
3 M Ω
I
B
e
o
I
I
e
I
I
B
I
B
Aux. amplifier for input
current compensation
1.5 M Ω
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LM2902