A charge-sharing switching scheme for SAR ADCs in biomedical applications

摘要

This paper presents a charge-sharing switching scheme for successive approximation register (SAR) analog-to-digital converters (ADCs) in biomedical applications. By using the charge sharing between two capacitor arrays to generate binary-weighted voltage-changes sequentially on the dummy capacitor, which is used to compare the multiple low bits, the proposed switching method enhances the efficiency of switching energy by 99.51% and achieves a 93.55% reduction in the total capacitor size, compared with the conventional SAR ADC.