A 1-V 1.1-μW sensor interface IC for wearable biomedical devices

An ultra-low-power, low-noise sensor interface IC dedicated for bio-signal acquisition is presented in this paper. The proposed system architecture is optimized to achieve a better trade-off between power consumption and noise figure. A 0.05 ~ 200 Hz bandpass function is embedded within the front-end amplifier, and a wide bandwidth buffer is inserted between the front-end amplifier and ADC to facilitate a power-efficient interface. The system also includes an 11-bit SAR ADC with nonlinearity of less than plusmn0.7 LSB. The measured input-referred noise is 2.1 muV integrated across the pass-band, achieving noise efficiency factor of 2.9, and the power consumption for the overall system is 1.1 muW under 1 V supply.