Unifying the concepts of offset voltage and common-mode rejection ratio [bipolar differential amplifiers]

A unified treatment of offset voltage and common-mode rejection ratio (CMRR) of bipolar differential amplifiers using large signal models is presented. The offset voltage expressions for the differential pair and 741 stages are first calculated in terms of transport model parameters. CMRR may then be calculated from these expressions. Two distinct mechanisms contributing to CMRR are identified.