Connecting two high gain fully differential opamps &#821

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dan11

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I need to connect in series two high gain fully differential opamps. They both have common mode feedback with high loop gain. Monte Carlo simulation show that due to mismatch there is a small DC offset at the output of 1st opamp. This offset is amplified as differential signal by the 2nd opamp. Is there a good solution for this problem?
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Re: Connecting two high gain fully differential opamps &

offset cancellation
it's necessary for high-gain amplification, otherwise you may have to increase the size of your input diff. pair to make a ultra-low-offset input.
anyway, it finally depends on how large the gain is. If the gain is not so large and you can tolerate some drift of the DC point, you'll be fine.
btw, even though you've solved the offset problem, noise and distortion would be another issue for high-gain amplification.
 
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