A Configurable 5.9 Mu W Analog Front-End For Biosignal Acquisition

This paper presents a configurable analog front-end (AFE) for the recordings of a variety of biopotential signals, including electromyography (EMG), electrocardiogram (ECG), electroencephalogram (EEG), action potential (AP) signals, etc. The first stage of the AFE employs a chopper-stabilized current-reuse complementary input (CRCI) telescopic-cascode amplifier to achieve high noise-power efficiency and suppress 1/f noise. A tunable impedance-boosting loop (IBL) is utilized, which is robust to process variation and parasitic capacitance and increases the input impedance from 4.3 M Omega to 102 M Omega.a The proposed AFE is fabricated in a 0.13 mu m CMOS process. The AFE has a mid-band gain from 45.2-71 dB. The low-pass corner is tunable in the range of 70-400 Hz and 1.2-7 kHz When configured for EEG recordings (0.7-100 Hz), the AFE draws 5.4 mu W from a 1.2 V supply while exhibiting input-referred noise of 0.45 mu Vrms, corresponding to a noise efficiency factor (NEF) of 3.7. When configured for AP recordings (0.7 Hz-7 kHz), the AFE consumes 5.9 mu W with input referred noise of 2.93 mu Vrms and a NEF of 3.0.