Fully differential operational amplifiers using CMOS compatible ateral bipolar transistors with improved common-mode regulation

Abstract

A new bias circuit for a CMOS compatible lateral bipolar transistor differential pair is presented. The circuit compensates for all process and bias dependent variations of the lateral collector current to emitter current ratio α. Experimental results show that its application to a fully differential amplifier improves the precision of the common-mode output voltage regulation by at least an order of magnitude.