Front-end amplifier of low-noise and tunable BW/Gain for portable biomedical signal acquisition

Abstract

We proposed a novel analog circuit design which is suitable for various biomedical signal acquisitions. In addition to the consideration of low power and low noise, the analog front-end integrated Circuit (AFEIC) is presented with design of high common-mode rejection ratio (CMRR) and high power supply ripple rejection ratio (PSRR). It has not only reduced the number of outer components, and enhances a better signal-to-noise ratio (SNR). The chip includes a current-balancing instrumentation amplifier, switched-capacitor filter, non-overlapping clock generator, and a programmable gain amplifier (PGA). It was fabricated by TSMC 0.35 mu m CMOS 2P4M standard process, with CMRR 155 dB CMRR, 131 dB of PSRR+, and 127 dB of PSRR- at 50 Hz. The power consumption is about 142.4 mu W under +/- 1.5V supply.