Analysis of common-mode rejection ratio of a CMOS differential amplifier considering all the non-idealities

This paper attempts an analytical approach to accurately determine common-mode rejection ratio (CMRR) considering the effects of various non-idealities such as the presence of channel length modulation, body effect, finite resistance of the current source, mismatches in transconductances and drain resistances between the two driver MOSFETS of a common source CMOS differential amplifier. This analysis brings to light the hitherto unforeseen dire impacts of these non-idealities put together on CMRR, and hence strongly suggests that these effects should not be, in any ways, ignored from theoretical calculations for CMRR. Moreover, the work would be helpful for researchers in this field to have a better insight on the differential amplifier circuits.