A novel simple and high performance structure for improving CMRR: Application to current buffers and folded cascode ampilifier

Abstract

A novel and simple structure for improving CMRR is introduced. This structure can be added to the circuits like folded cascode amplifier, telescopic amplifier, current buffers, .etc to improve the CMRR of these circuits. This simple and effective circuit uses common mode deviating technique to improve CMRR at least 12dB while preserves CMRR bandwidth which is a novel technique in order to improve CMRR. Application of this structure in both current buffer and folded cascode structures are shown. Simulation results in TSMC 0.18µm CMOS technology with HSPICE are presented to demonstrate the validity of the proposed circuit. In addition Monte Carlo analysis is performed to simulate the fabrication condition.