Capacitor array structure and switching control scheme to reduce capacitor mismatch effects for SAR analog-to-digital converters

摘要

This paper presents a new capacitor array structure developed for SAR analog-to-digital converters and its switching algorithm that can alleviate capacitor mismatch effects. The capacitor mismatch can induce many missing codes. The proposed capacitor array structure is based on the junction-splitting method as is efficient in terms of power consumption. To reduce the capacitor mismatch effects, two capacitor arrays are employed to enable redundant search. Simulation results show that the proposed method significantly reduces the number of missing codes caused by the capacitance mismatch, and reduces the energy consumption by more than 70% compared to the conventional charge redistribution method.