A 10-bit 500-KS/s low power SAR ADC with splitting comparator for bio-medical applications

This paper presents a successive approximation register analog-to-digital converter (SAR ADC) design for bio-medical applications. Splitting comparator and energy saving capacitor array are proposed to achieve low power consumption. The average switching energy of the capacitor array can be reduced by 69% compared to a conventional switching method. The measured signal-to-noise-and-distortion ratios of the ADC is 58.4 dB at 500KS/s sampling rate with an ultra-low power consumption of 42-μW from a 1-V supply voltage. The ADC is fabricated in a 0.18-μm CMOS technology.