Hi,everybody! I got a problem now and need your help! I want to amplify an signal that it’s DC value maybe change, then I add a CAP to get the AC siganl. Next,I want to amplify that ac signal about 20dB. The output is diffrenetial, so I want to let CM level to be 0.9V. VCM is the reference given from outer. what kind of structures should I choose ? THANKS A LOT!
are you looking for a fully differential opamp? if so that slowly varying dc which would be common to both inputs wont be seen at the output, with the fully differential opamp we need to have a cmfb circuit.