PSRR improvement technique for single supply class AB power amplifiers

A simple circuit technique for improving the midband positive power supply rejection ratio (PSRRdd) of gain boosted class AB power amplifiers is presented. The technique takes advantage of the bias network and inherent narrow gain boosting amplifier bandwidth and therefore does not require any additional components. Measurements show that more than 20 dB improvement in the midband PSRRdd is obtainable at a frequency of 100 kHz.