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Simulators >> Circuit Simulators >> about fully differential opamp
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Message started by lhlbluesky_lhl on Sep 26^th, 2010, 7:43am

Title: about fully differential opamp
Post by lhlbluesky_lhl on Sep 26^th, 2010, 7:43am

for a fully differential opamp, how to simulate its PSRR, CMRR, ac noise, CMIR, output swing, etc, in ellen's book, i can find the simulation methods for single-ended opamp (for the above parameters), but what for fully differential opamp?

besides, for ac noise simulation of fully differential opmap, there are two input ports which include ac signal (Vin+: ac=1V, Vin-: ac=-1V in my case), so, is the ac noise measured in Vout+ node or Vout- node or for both Vout+ and Vout- node? in another word, the ac noise for fully differential opamp is two times as the same single-ended opamp, am i right? if not, please correct me.

finally, how to measure the CM gain of fully differential opamp? as we know, CMRR=Av,DM/Av,CM, so i want to get the CM gain for my fully differential opamp. and how to measure the CM gain of single-ended opamp?

thanks all for reply, thanks all.