An 8-channel power-efficient time-constant-enhanced analog front-end amplifier for neural signal acquisition

In this paper, an 8-channel low-power analog front-end amplifier (AFEA) with time-constant-enhanced topology is proposed for neural signal acquisition. The AFEA is composed of eight time-constant-enhanced amplifiers (TCEAs) and high-pass filters (HPFs), a multiplexed transconductor (MGM) and a transimpedance amplifier (TIA). The AFEA is designed and simulated in 65nm CMOS technology. The bandwidth of the AFEA is 7 kHz, and the maximum gain is 61.2 dB with power consumption of 1.77 μW per channel. The TCEA is designed to reduce the high-pass cut-off frequency to 0.16 Hz and achieve a high gain of 50.7 dB with only 4 pF input capacitance. The power consumption of TCEA is 1.08 μW under 1-V power supply. The noise efficiency factor (NEF) of the TCEA is 2.13 with 4.46 μV_rms input-referred noise.