Patent ID: 7276968

Claim:
A class D amplifier comprising: a pair of switching elements composed of first and second switching elements which are complementally symmetrical with respect to high and low voltages of a power supply; first bias voltage level shift means that generates a drive signal to be supplied to said first switching element by level-shifting a square-wave first input signal; and second bias voltage level shift means that generates a drive signal to be supplied to said second switching element by level-shifting a square-wave second input signal, said class D amplifier being provided for performing class D amplification by allowing said first and second switching elements to perform a push-pull operation based on the respective drive signals supplied thereto, wherein said first bias voltage level shift means has first differential amplification means that calculates a differential signal between said first input signal and a predetermined voltage, and first bias means that generates a level-shifted drive signal to be supplied to said first switching element by pulling up said differential signal towards the power supply voltage of the first switching element, wherein said second bias voltage level shift means has second differential amplification means that calculates a differential signal between said second input signal and a predetermined voltage, and second bias means that generates a level-shifted drive signal to be supplied to said second switching element by pulling down said differential signal towards the power supply voltage of the second switching element.