Common-mode rejection ratio redefined
Frank T. Koide · IEEE Transactions on Instrumentation and Measurement · 1997
Redefining the common-mode rejection ratio (CMRR), a set of equations is derived for the common-mode gain and the CMRR of differential amplifiers. The results, which are consistent with practice and simulation, show that an amplifier's CMR may exceed the CMR of the active device(s) by intentional unbalancing of the circuit.