Energy‐efficient high‐accuracy switching method for SAR ADCs

Abstract

A new tri‐level switching method for successive approximation register (SAR) analogue‐to‐digital converters (ADCs) is presented. The proposed switching method enhances the efficiency of digital‐to‐analogue converter switching energy by 93.7% and achieves a 75% reduction in the total capacitor size, compared with the conventional SAR ADC. In addition, the accuracy of the proposed SAR ADC has no dependency on the accuracy of the mid‐level reference voltage ( V cm ) except in the least significant bit, and the common‐mode voltage at the input of the comparator will remain approximately unchanged. Analytical calculations and behavioural simulation results are provided to demonstrate the effectiveness of the proposed switching scheme.