High Speed Low Power CMOS Comparator for Pipeline ADCs

This paper describes and analyzes a low power and high speed differential comparator. The designed comparator is intended to be implemented in a 10bit 20MHz pipeline analog-to-digital converter dedicated to RF WLAN applications. This comparator is based on the switched capacitor network using a two-phase nonoverlapping clock. The offset voltage of the designed comparator has been reduced by means of an active positive feedback. The analyses and simulation results which have been obtained using 0.8mum CMOS AMS process parameters, with a power supply voltage of 5V and an input common mode of 2-3V, show that this comparator exhibits a propagation delay of 17.3ns, a good accuracy and a low power consumption of about 0.8mW