A low-offset analogue front-end IC for multi-channel physiological signal acquisition.

This paper describes a low-offset analogue front-end (AFE) integrated circuit (IC) for multi-channel physiological signal acquisitions. The mixed signal IC consists of low-offset gain programmable instrumentation amplifiers (GPIAs), high sensitive current-to-voltage converters (I-V converters), reference and an 8-bit analogue-to-digital converter (ADC). The IC offered adjustable gains that were elaborated for various physiological signal acquisitions. The conditional signals were quantized by ADC that offered an optimal solution for portable applications. The circuit was fabricated in SMIC 0.18-mum mixed-signal CMOS technology, and core area of the whole IC measured 1.36 mm(2). The post-annotated simulations suggested that the system achieved a common-mode-rejection-ration (CMRR) of 142 dB, the adjustable gain from 31.6 dB to 76.5 dB, and the offset voltage less than 80 microV. The 8-bit ADC exhibited less than 0.8 LSB DNL and 1.1 LSB INL. Power dissipation of each channel and the ADC were approximately 348 microW and 1.65 mW under a 1.8 V single supply voltage, respectively. It is suitable for a wide range of high precision biomedical applications.