Patent ID: 8526640

Claim:
An apparatus for switching audio amplification comprising: a plurality of first switching devices each of which is coupled between a first output terminal and a respective one of a plurality of different voltage potentials, each of the first switching devices having a corresponding control terminal; a plurality of second switching devices each of which is coupled between a second output terminal and a respective one of the different voltage potentials, each of the second switching devices having a corresponding control terminal; a third switching device, coupled between the first output terminal and a first voltage potential, having a corresponding control terminal, wherein each of the different voltage potentials is greater than the first voltage potential; a fourth switching device, coupled between the second output terminal and the first voltage potential, having a corresponding control terminal, wherein each of the first and second output terminals provides a corresponding voltage level of the different voltage potentials; and a control signal generating circuit, coupled to the control terminals, for multi-level pulse width modulating the first and second switching devices to generate a differential signal between the first and second output terminals.