Patent ID: 8279011

Claim:
An amplifier circuit, comprising: a first amplifier, comprising a first terminal, a second terminal, a third terminal, a fourth terminal, and a fifth terminal, wherein the first terminal is coupled to a first external voltage, the second terminal is coupled to a negative voltage, the third terminal is coupled to a ground reference voltage, the fourth terminal is coupled to a first input signal, the fifth terminal is coupled to a first speaker; a second amplifier, comprising a sixth terminal, a seventh terminal, an eighth terminal, a ninth terminal, and a tenth terminal, wherein the sixth terminal is coupled to the first external voltage, the seventh terminal is coupled to the negative voltage, the eighth terminal is coupled to the ground reference voltage, the ninth terminal is coupled to a second input signal, the tenth terminal is coupled to a second speaker; and a charge pump, coupled to the first amplifier and the second amplifier, providing the negative voltage transformed from a second external voltage.