A low power level-crossing ADC for wearable wireless ECG sensors

Ultra-low power consumption is desired in most wearable biomedical devices. The event-driven based Analog-to-Digital converter (ADC) could be an excellent candidate for low power system because of the reduction in sampling points for biosignals. In the existing event-driven based ADC architectures, two or more high precision comparators are utilized to sample the input signal. In this paper, we propose a new scheme utilizing only one high precision comparator to genertate samples with the assistance of a low precision one. From the Matlab simulations on real ECG signal, it is shown that around 25% reduction on the number of samples can be be achieved compared with the Nyquist sampling scheme.