A $43.8\mu \mathrm{W}$ per Channel Biopotential Readout System using Frequency Division Multiplexing with Cable Motion Artifact Suppression

Abstract

This paper presents a fully-integrated biopotential readout system using frequency division multiplexing (FDM) for general purpose, multi-channel biopotential signal acquisition. FDM reduces the number of required cables between active electrode and back-end readout, and frequency translation prior to transmission mitigates low-frequency motion artifacts and mains interference in the cable. The 4-channel EMG/ECG architecture carries all channels over a 3-wire interface and attenuates low-frequency cable motion artifacts by 15X and 60 Hz mains noise coupled into the cable by 62X. The IC is fabricated in 180 nm CMOS, including both front-end active electrode and back-end demodulation architectures; each 1 Hz-150 Hz, differential active electrode channel occupies 0.75 mm2 and consumes 43.8 $\mu \mathrm{W}$.