A 1.7μW/Channel Time-Division-Multiplexing Analog Front-End for Bio-Potential Recording

This brief presents a low-power multi-channel analog front-end (AFE) for bio-potential recording. Time-division-multiplexing (TDM) technique is used to save chip area by sharing one ADC among multiple recording channels. To reduce the power consumption brought by additional ADC drivers, buffers are only turned on while connected to the ADC. The chip is implemented in a 65 nm CMOS process. The AFE consumes 29
$\mu \text{W}$
under 1 V supply. Measurement results show that the AFE achieved an input referred noise of 1.34
$\mu $
Vrms in a 350 Hz bandwidth and a NEF of 3.58 for the analog recording chain. The analog signals of all channels are converted to digital code at 20 kS/s by a 12-bit SAR ADC with 66.1 dB SNDR. The AFE chip is experimented by measuring human ECG.