An Analysis of CMOS Latched Comparators

Abstract

Using suitable types of CMOS latched comparators for specific conditions is vital -because each comparator has different pros and cons. Also, it is important to determine which comparators to utilize for specific conditions. A need remains for the practical comparison of various types of comparators with applicable criteria. Within the present study, we performed comparisons between StrongArm latch, modified double-tail latch, and track-and-regenerate slicer with three different types of criteria. We analyzed each comparator by controlling three types of variables: power supply, input common mode voltage, and differential signal input. Then, in keeping with these three types of criteria, the simulation results, kickback noise, power consumption, and clock-to-Q delay were evaluated. We designed three kinds of CMOS latched comparators with 40-nm CMOS technology. In post-layout simulations, using a StrongArm latch resulted in low power consumption. Modified double-tail latch showed strength in kickback noise and is applicable for low power supply. Track-and-regenerate slicer showed better performance in clock-to-Q delay. Our findings expand on the performance of each comparator that would be applied to mixed-signal circuits and systems.