subgold
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hi,
i dont know your output range and desired cm level, but given an folded cascode output, 70mV of cm offset basically indicates your dda is just inactive, i am afraid you will suffer a serious CMRR degradation.
i think berti's suggestion might be helpful as long as you still have some freedom to manipulate the gain and speed of the main amp. you could also try to optimize the sizing of your cascode transistor and find a better way of feeding back your cmfb loop.
otherwise i see no choice but burning more current into your dda.
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