Patent ID: 6181202
Filing Date: 2001-01-30
Classification: H01L,H03F

Abstract:
A CMOS differential amplifier for amplifying a difference in level between input voltages comprising: an input stare having at least a pair of input terminals for receiving input voltages; and a current mirror stage; wherein at least one transistor in the input stage is a bipolar transistor formed by a CMOS process, so that the input offset voltage of the differential amplifier circuit is smaller than if said element were a CMOS element formed by a CMOS process; and wherein the bipolar transistor comprises a CMOS transistor having source and drain regions formed in a substrate and driven in a bipolar mode, wherein the source region serves as the emitter of the bipolar transistor, the drain region serves as the collector of the bipolar transistor and a region of the substrate proximate the source and drain regions serves as the base of the bipolar transistor.