Single-supply precision rectifier

The precision full-wave rectifier circuit shown in the diagram accepts a.c. inputs of up to ±3 V, yet operates from a single +5 V supply voltage. The quiescent current is only 320 µA. Rectifier gain is unity, with the gain accuracy almost entirely dependent on the match between the two resistors 2R1. The frequency range is about d.c. to 2 kHz. The single-supply operation at very low quiescent current drain makes the circuit particularly useful for battery-powered equipment.