Analog front-end amplifier for ECG applications with feed-forward EOS cancellation

Abstract

This paper presents a low-noise low-power Instrumentation Amplifier (IA) for ECG applications. Chopped capacitively-coupled IA (CCIA) is built to precisely define the gain and avoid flicker noise. The circuit for electrode offset (EOS) cancellation is implemented in feed-forward (FF) manner with an area-efficient SC integrator. The FF architecture uses less capacitor ratio to define the low HPF corner than the feedback architecture. Implemented in a 0.18-μm process, the circuit draws 4.2 μA from a 1.8 V supply, and occupies 0.63mm2. The total integrated noise from 0.5 to 100Hz is 7.37 μVrms.