A low-power fully differential reconfigurable biomedical electronics interface to detect heart signals

A biomedical electronics interface to detect heart signals is presented including a reconflgurable full differential fifth-order Bessel Gm-C filter and a 12 bit low-power fully differential successive approximation register analog-to-digital converter (SAR ADC). The total fully differential structure reduces the input signal noise and distortion effectively. A switch array is used in Gm-C filter to realize three low cutoff frequencies for different biomédical signals processing. In SAR ADC, hybrid 9-bit charge-redistribution and 3-bit resistor binary-weighted DAC techniques and dynamic latch comparator are adopted to achieve optimization of resolution, area and power consumption. Fabricated in SMIC 0.18-μm 1P6M mixed-signal CMOS technology, the proposed biomédical electronics detecting interface only consume below 100μW under 1.8V supply voltage.