Patent ID: 8605915

Claim:
A class G audio amplifier, comprising: an input port configured to receive an input signal; an audio output stage coupled to the input port, wherein the audio output stage is configured to output an amplified audio signal that is based on the input signal; a level detector coupled to the input port, wherein the level detector is configured to detect a level of the input signal and to output a detected level signal based on the detected level of the input signal; and a charge pump coupled to the level detector, wherein the charge pump is configured to provide a positive power supply voltage and a negative power supply voltage in response to the detected level signal, the positive power supply and the negative power supply being coupled to power the audio output stage, and wherein the charge pump comprises: a power supply coupled to a positive output of the charge pump via a third switch; a positive power capacitor coupled between the positive output of the charge pump and ground; a negative power capacitor coupled between a negative output of the charge pump and ground; a first fly capacitor having a first terminal and a second terminal, wherein the first terminal is controllably coupled to the power supply via a first switch, the first terminal is also controllably coupled to the positive output of the charge pump via a fourth switch, and the first terminal is also controllably coupled to ground via a second switch; a second fly capacitor having a first and a second terminal, wherein the first terminal is controllably coupled to the first terminal of the first fly capacitor via an eighth switch, and the first terminal is also coupled to the second terminal of the first fly capacitor via a tenth switch; and the second terminal is controllably coupled to: (i) the positive output of the charge pump via a fifth switch; (ii) ground via a sixth switch; (iii) the second terminal of the first fly capacitor via a ninth switch; and (iv) the negative output of the charge pump via a seventh switch.