Patent ID: 7420422

Claim:
An audio amplifier driven by single voltage source comprising: a voltage supply circuit comprising: a first voltage source; a first switch having a first terminal coupled to the first voltage source; a second switch having a first terminal coupled to a second terminal of the first switch, and a second terminal coupled to ground; a first capacitor having a first terminal coupled to the second terminal of the first switch, and a second terminal; a third switch having a first terminal coupled to the second terminal of the first capacitor, and a second terminal coupled to ground; a fourth switch having a first terminal coupled to the second terminal of the first capacitor, and a second terminal; and a second capacitor having a first terminal coupled to the second terminal of the third switch, and a second terminal coupled to the second terminal of the fourth switch; and an audio amplifier set comprising: a plurality of sub-audio amplifiers, each of which having a positive voltage input terminal coupled to the first voltage source, and a negative voltage input terminal coupled to the second terminal of the second capacitor.