Class AB amplifier with enhanced slew rate and GBW

摘要

The design of a micropower class AB operational transconductance amplifier with large dynamic current to quiescent current ratio is addressed. It is based on a compact and power-efficient adaptive biasing circuit and a class AB current follower using the quasi-floating gate (QFG) technique. The amplifier has been designed and fabricated in a 0.5-mu m CMOS process. Simulation and measurement results show a slew rate (SR) improvement factor versus the class A version larger than 4 for the same supply voltage and bias currents, as well as enhanced small-signal performance.