AnsweredAssumed Answered

circuit for ultra precision INA @gain = 1.0

Question asked by Alexxx on May 24, 2018
Latest reply on May 24, 2018 by Emman.A

I want an output signal which is the difference of Vexcit+ to Vexcit- (up to +/-5V each) to be ground referenced with high accuracy.
Normally this is the job of an INA. But at gain 1 the output offset voltage of AD8421 is dominant.
In my actual test circuit I measure overall offset voltage of 220µV.
Is there any precision INA with <<25µV overall-offset?
Is there a discrete circuit (with zero-drift-OPAs + LT5400??) that has high CMRR, high stability and exceptionally low offset voltage?
The circuit should be able to process sine input up to 200Hz.

Outcomes