Novel low-voltage high-CMRR input stage for current feedback operational amplifiers (CFOA)

Abstract

In this work a novel current feedback operational amplifier (CFOA) is presented whose Common-Mode Rejection Ratio is remarkably increased exploiting a novel Common Mode Feed Forward (CMFF) technique to compensate the output common mode signal. The complete stage is designed with model parameters of AT&T's ALA400 CBIC-R process and simulated with PSPICE. The presented CFOA achieved 145dB CMRR which is 80 dB higher than CMRR of the conventional CFOA. It can properly work with power supply down to ±1.5V suitable for current mix-mode chips (SOC).