Analog front-end for EMG acquisition system

Abstract

This paper presents a 4-channel analog front-end (AFE) for Electromyogram (EMG) acquisition systems. Each input channel consists of a chopper-stabilized instrumentation amplifier (IA) and a low-pass filer (LPF). A 15-bit analog-to-digital converter (ADC) with a buffer amplifier is shared with four input channels through multiplexer. An incremental ADC with a 1.5-bit second-order feed-forward topology is employed to achieve 15-bit resolution. The prototype AFE is fabricated in a 0.18 μm CMOS process with an active die area of 1.5 mm2. It achieves 3.2 μVrms input referred noise with a gain of 40 dB and a cutoff frequency of 500 Hz for LPF while consuming 3.713 mW from a 1.8V supply.