CMOS operational amplifiers with continuous-time capacitive common mode feedback

Abstract

A simple and power efficient approach for the implementation of continuous-time common mode feedback networks using a capacitive averaging network is introduced. It is shown that low voltage, continuous-time, fully differential rail to rail operation can be achieved using the proposed technique. This at the expense of very small additional hardware and no additional power dissipation One stage, two stage, telescopic and folded cascode op-amps are discussed as application examples.