High performance CMOS current comparator

Abstract

A new high-speed CMOS current comparator is described. By changing the buffer of an existing comparator from class B to class AB operation, voltage swings are reduced, resulting in greater speed for small input currents. Simulation results employing a 1.6 µm CMOS technology show the response time to a 0.1 µA input current to be 11 ns and the power dissipation to be 1.4 mW, resulting in a five times improvement in speed/power ratio over existing high-speed current comparators.