A 1-V MOSFET-only fully-differential dynamic comparator for use in low-voltage pipelined A/D converters

Abstract

Low-voltage low-power comparators implemented in standard digital processes are of increasing importance in different integrated applications. In this paper a 1-V fully-differential low-power MOSFET-only comparator with rail-to-rail input swing is presented which can be suitably used in very low-voltage low-power pipelined A/D converters. This comparator utilizes a resistive divider configuration with a MOSFET-only clock booster to supply a higher voltage for the dynamic latch in the intervals that a comparison is to be made. HSPICE simulations of the proposed comparator in a 0.25-μm CMOS process, confirm the rail-to-rail input range of the fully-differential comparator with a supply voltage of 1 V with a decision time of less than 1 ns while driving a capacitive load of 0.2pF. The worst-case dynamic power consumption of the proposed comparator is less than 100μW with a clock frequency of 50MHz.