Newbie level 5
For an opamp in open look configuration,
Here Ad should be equal to open loop gain of opamp and
Now consider the closed loop config of opamp (negative feedback used):
However, Ad is closed loop gain here (according to Sedra Smith) and
In terms of open loop gain,
A is open loop gain here.
So Adm is open loop gain in the first case and Adm is closed loop gain in the second case. How to know which gain to use in CMRR?
Reference: Microelectronic Circuits (Seventh Edition) by Sedra Smith