A Low-Power Current-Mode Front-End Acquisition System for Biopotential Signal Recording

Abstract

In this paper, a new current-mode front-end amplifier for biopotential signal recording system is proposed. A current-mode preamplifier incorporates with an active feedback loop to bypass any dc current generated by tissues is designed as the first stage. A programmable gain stage and a current-mode filter are designed to adjust both gain and the low-pass cutoff frequency, respectively. The current-mode front-end amplifier is designed and fabricated in 0.18-mu m CMOS technology. The measured maximum current gain is 55.9 dB. The high-pass cutoff frequency can achieve as low as 0.3Hz and the low-pass cutoff frequency can be adjusted from 1 KHz to 10 KHz. The measured input-referred noise is 153 fA/ root Hz, and the power consumption is 13 mu W at 1-V power supply.