A 5.3-nV/√Hz Noise Density Switched-Capacitor Programmable Gain Amplifier with kT/C Noise Reshaping and Ping-Pong Topology

Abstract

This paper presents an implementation of a 5.3-n V/√Hz noise density switched-capacitor (SC) programmable gain amplifier (PGA) with a 500-uA current consumption under a single 3.3 V supply. It employs a kT/C noise reshaping technique to reduce the kT/C noise caused by sampling at a lower frequency. The common-mode sampling (CMS) is also used to achieve the split between the input common-mode voltage sampling and the noise sampling that ensures the kT/C noise is reshaped. The CMS guarantees that the kT/C noise introduced by the input chopper switches only has an impact on the common-mode noise. In addition, a ping-pong topology is used to attenuate the output aliased noise and obtain a fast settling.