Very low-voltage class AB CMOS precision voltage and current rectifiers

Abstract

Simple class-AB CMOS voltage and current precision rectifier circuits that operate from a single supply close to a transistor's threshold voltage are introduced. The current rectifier has output voltage swings comparable to the supply voltage and the voltage rectifier has wide input and output swings. Simulations of both rectifiers operating at 20 MHz are shown. Experimental results of a test chip are presented that verify the proposed circuits. A full wave precision rectifier based on the proposed rectifier cells is discussed.