Abstract: An amplifier includes an input stage, a comparator coupled to an output of the differential input stage, and a trimming controller coupled to an output of the comparator. The input stage includes a plurality of trim devices coupled in parallel with a first input device. The trimming controller is adapted to configure the trim devices based on an output of the comparator. The trim devices may selectively control a total effective device area of the first input device. Each of the trim devices, when enabled, may add a specified area to the total effective device area of the first input device. The input stage may also include a second plurality of trim devices coupled in parallel with a second input device.

Abstract: An apparatus and method are provided for a Class G amplifier that includes an output stage, where an output stage supply voltage is selected based upon an input signal voltage of the output stage. The amplifier may also include an input stage coupled to the output stage, where the input stage generates the input signal voltage for the output stage. The output stage may include first and second MOS devices operating as a Class AB amplifier, and the output stage supply voltage selected based upon gate voltages of the MOS devices. The supply voltages may be generated by a buck converter, and a charge pump that is coupled to the buck converter.