A Low-power Design of Common-mode Feedback Circuit for Fully-differential Operational Amplifiers

Common-Mode Feedback (CMFB) is an integral part of a fully differential (FD) operational amplifier (OTA). This paper presents the design of CMFB using continuous-time and discrete-time switched capacitor (SC) techniques for the same FD-OTA, and simulates them in the TSMC 0.18mum process. The results indicate that the SC CMFB with appropriate capacitor sizing exhibits lower power consumption and better feedback performance.