A 20 μW dual-channel analog front-end in 65nm CMOS for portable ECG monitoring system

This paper presents a dual-channel analog front-end (AFE) for portable ECG monitoring system. The AFE consists of an instrumentation amplifier, a DC servo loop (DSL), a fixed gain amplifier (FGA), a programmable gain amplifier (PGA) and an ADC buffer. To achieve high input impedance, a DC-coupled current feedback instrumentation amplifier (CFIA) is adopted. Fabricated in 65nm CMOS process, the AEF occupies 0.16mm² area and consumes 20μW. Measurement results show that the AFE achieves 2.5GΩ input impedance, 73dB CMRR at 50Hz and 40/53.7dB tunable gain.