Typical single-supply applications

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DocID026928 Rev 1

Figure 26. Using symmetrical amplifiers to reduce input current (general concept)

Figure 24. High input Z, DC differential amplifier

Figure 25. Low drift peak detector

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RT2902

R1

100 k

Ω

R2

100 k

Ω

R4

100 k

Ω

R3

100 k

Ω

+V 2

+V 1

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eo = [ 1 +

] (e2 - e1)

As sho wn eo = (e2 - e1)

R4

R3

I

B

2N 92 9

0.001

μF

I

B

3R

3 M

Ω

I

B

Input current

compensatio n

I

B

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Z

o

Z

I

C

1

μF

R

1 M

Ω

* P olycarbonat e or polyethylen e

*

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RT2902

I

B

2N 92 9

0.001

μF

I

B

3 M

Ω

I

B

I

I

I

B

I

B

Aux. amplifie r for input

current compensatio n

1.5 M

Ω

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RT2902