Two advanced energy-back SAR ADC architectures with 99.21 and 99.37 % reduction in switching energy

Abstract

This letter presents novel energy-efficient switching schemes for a successive approximation register analog-to-digital converter. The new switch method consumes no switching energy in the first three comparison cycles. The average switching energy is reduced by 99.21 and 99.37 % for the signal-independent and signal-dependent common mode voltage at the comparator, respectively. A 75 % reduction in the total capacitance over the conventional scheme is also achieved. The variation of the common mode voltage at the comparator input in the proposed architecture is 50 % less than in other low power switching schemes.