Patent ID: 6252458
Filing Date: 2001-06-26
Classification: H03F

Abstract:
A differential amplifier comprising:an integrated resistance load type differential pair;a gain variation suppressing type current source for generating a first predetermined constant current to suppress a small signal gain variation of the integrated resistance load type differential pair, caused by variations of circumferential conditions and manufacturing process conditions;a resistance variation suppressing type current source for generating a second predetermined constant current to suppress a limiter amplitude variation of the integrated resistance load type differential pair, caused by variations of the circumferential conditions and the manufacturing process conditions;a mixing means connected to the gain variation suppressing type current source and the resistance variation suppressing type current source for mixing the first and second predetermined constant currents mixed at a constant ratio under a condition most frequently used among the circumferential conditions and best achieved among the manufacturing process conditions, anda bias current source connected to the integrated resistance load type differential pair to provide a constant current mixed by the mixing means as a bias current for the integrated resistance load type differential pair.