A low-offset calibration-free comparator with a mismatch-suppressed dynamic preamplifier

Abstract

This paper presents a new low offset comparator with a mismatch-suppressed dynamic preamplifier Various mismatches contribute to comparators's input referred offset. The proposed mismatch suppression is achieved by sampling the mismatches at the dynamic preamplifier's output node during the precharge phase. A time-domain analysis method is utilized to quantize the suppression effects. By the techniques, a 1-GS/s four-input comparator is implemented by 65-nm CMOS technology. It achieves a 60-μW power dissipation and a 1.89-mV 1-sigma(σ) offset voltage, which is a 90% improvement compared to its non-suppressed counterparts.