A Flying-Capacitor-Based Reset Scheme for Low Power Dynamic Comparator

A dynamic comparator reset scheme based on the flying capacitor is proposed. The reset power used to charge the integration nodes of the comparator is nearly halved by exploiting the existent integration capacitors with only a single D-flip-flop and few switches. The proposed reset scheme improves the energy efficiency while the small CLK-OUT delay of the dynamic comparator is maintained. The prototype comparators with the conventional or the proposed reset scheme are fabricated in a 22-nm bulk CMOS process. The measurement results of the delay, input-referred noise, and energy consumption show that the flying-capacitor-based reset scheme boosts the overall performance of both the conventional StrongARM and Elzakker’s comparator by about 1.8-times.