A Frequency-Division Multiplexed 16-Channel AFE for Wearable MC-sEMG Recording

This paper presents a 16 -channel analog frontend (AFE) for wearable multi-channel surface electromyography recording. The proposed architecture adopts frequency-division multiplexing (FDM), enabling extensive sharing of signal conditioning circuitry and requiring only three cables for transmission to an external back-end for digital signal processing. Benefiting from the up-conversion process, the FDM signal exhibits robustness against cable motion artifacts and mains interference, allowing short-distance communication without compromising signal quality. This work achieves a channel-to-cable ratio of 16:3, dramatically reducing system complexity. Implemented in a 180 nm CMOS technology, the proposed 16-channel AFE occupies only <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$6.42 ~\text{mm}^{2}$</tex> and consumes <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$40.1 \mu ~\mathrm{W}$</tex> per channel from a 1.5 V supply. Measurements on a forearm demonstrate the capability to simultaneously detect muscle activation from various muscle groups, showcasing its potential for gesture recognition applications.