A Kick-Back Reduced Comparator for a 4-6-Bit 3-GS/s Flash ADC in a 90nm CMOS Process

This paper presents a kick-back reduced comparator based on a sense-amplifier type comparator. The kickback charge and resulting voltage peak is reduced by 6times, which corresponds to a power reduction in the input driver and the resistance ladder of the same magnitude. A 4-6-bit 3-GS/s low-power flash ADC using the proposed comparator has been implemented in a 90 nm CMOS process. The significantly lower requirements on input driver and resistance ladder have reduced the overall ADC power dissipation by 50%.