chopper amplifier, feedback feasible?

I'm not sure if you have got the concept straight. Besides, I can't see how any kind of amplifier can help you "remove" any kind of noise from a signal. If all you want is an amp with very low 1/f noise, maybe a chopper stabilized opamp is what you need.

robert

I just read some more on chopper amps (....prompted by your comment :-)). I get it now, chopper amps remove/attenuate the 1/f noise contribution of the amp only. Hmmm..... I guess I will have to find a way to introduce the the chopper amp in the feedback loop that is responsible for producing the very-noisy 1/f signal. That should not be too difficult (i hope) since the noisy signal stems from an op- amp in follower configuration. That brings me back to my original question, can chopper amps function with feedback ?

-Roger

On 5 Apr 2007 08:04:31 -0700, Roger Bourne wrote

Without knowing any more about the kind of signal being processed, this brings me back to my original suggestion: Read up on chopper-stabilized opamps (very different from chopper amps which have gone out of fashion decades ago). Possibly you can just replace your noisy opamp follower by dropping in a chopper stabilized one and be done.

When doing research on this, you can also look for "zero drift" opamps which is another name for the same thing. LT have a few cute app notes on their site

robert