2, how to do the AC simulation for the OTA used in SHA?
I know ,for the stability ,we should simulate the loop gain( Af) and phase to verify the PM is enough or not. But the feedback capacitor(Cf) connects the input and output of the OTA. how do i open the loop? why?
I found many thesis just open the Cf and let the Cf to be the OTA loading( of cause , the loading include other's capacitors) , then simulate it. But I think it looks like doing the open loop simulation for OTA. I am not sure i am right or not?