Minimization of the common mode gain in differential amplifiers
Abstract
The dependence of the common mode gain of differential amplifiers on the output impedance of the current source is investigated. It is shown that at zero frequency there exists a value of source resistance which causes the common mode gain to be zero. This critical value does not depend significantly on frequency, although at nonzero frequencies, the common mode gain will be greater than zero. Furthermore, it is shown that the differential amplifier need not be balanced. However, in case of an unbalanced circuit there exists for each of the output terminals a distinct critical value of source resistance.
 Publication:

International Journal of Electronics
 Pub Date:
 October 1974
 Bibcode:
 1974IJE....37..539D
 Keywords:

 Computer Aided Design;
 Differential Amplifiers;
 Electrical Impedance;
 Frequency Response;
 Power Gain;
 Transistor Amplifiers;
 Amplifier Design;
 Equivalent Circuits;
 Figure Of Merit;
 Integrated Circuits;
 Optimization;
 Electronics and Electrical Engineering