Differential amp

Thread Starter

TAKYMOUNIR

Joined Jun 23, 2008
352
What is the input on pin2 and pin3 and what is the vo
thanks AND IF I NEED THE VO TO BE 10 V WHEN THE INPUT VOLTAGE 1000V WHAT IS THE VALUE OF RESISTORS IN THIS CASE
 

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crutschow

Joined Mar 14, 2008
34,283
The circuit is a differential input design so the differential gain is R5 / (R3+R4) for ideal resistors (much less than 1 in this case). Vo thus is equal to the total value of the input voltage (V1-V2) times this gain value. I'll leave the calculations as an exercise for the reader.

Note that for real resistors you will need to take the resistor tolerance into account.
 

Thread Starter

TAKYMOUNIR

Joined Jun 23, 2008
352
The circuit is a differential input design so the differential gain is R5 / (R3+R4) for ideal resistors (much less than 1 in this case). Vo thus is equal to the total value of the input voltage (V1-V2) times this gain value. I'll leave the calculations as an exercise for the reader.

Note that for real resistors you will need to take the resistor tolerance into account.
v1-v2=0v or 600v and what is the voltage across d1 and d2
thanks
 

ramancini8

Joined Jul 18, 2012
473
The sad news is that unless the external components are matched you get an error because the mismatch creates a differential signal. If you use 3% resistors, and the mismatch between input resistors is 3%, you get an 18V error. Differential amps are very hard to make.
 

Ron H

Joined Apr 14, 2005
7,063
The sad news is that unless the external components are matched you get an error because the mismatch creates a differential signal. If you use 3% resistors, and the mismatch between input resistors is 3%, you get an 18V error. Differential amps are very hard to make.
I'll believe 18mV error.:confused:
 

crutschow

Joined Mar 14, 2008
34,283
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