A 1 volt simplified comparator with nonlinear class-AB driver and rail-to-rail output stage

摘要

A voltage comparator is described which can operate at a power supply down to 1 V and has a rail-to-rail class-AB output stage. The circuit consists of only 43 transistors and has a quiescent current of 160 mu A. The circuit is intended as an on-chip building block. The comparator is integrated in a standard semicustom BICMOS process with lateral PNPs. In this process a response time of 500 ns is achieved. The comparator has been made with ft=3 GHz at 1 mA for the NPN transistors and ft=20 MHz at 20 mu A for the lateral PNP transistors.