Patent ID: 7944289
Filing Date: 2011-05-17
Classification: H03F

Abstract:
1. A class-D amplifier, comprising: a first input to receive a first voltage; a second input to receive a sawtooth wave signal; a third input to receive a second voltage; a fourth input to receive an audio input signal; a first comparator coupled to the first and second inputs to compare the first voltage with the sawtooth wave signal to thereby generate a first signal; a second comparator coupled to the second and third inputs to compare the second voltage with the sawtooth wave signal to thereby generate a second signal; a switching circuit coupled to the first, second and third inputs and the first and second comparators, to switch the first voltage, the sawtooth wave signal, or the second voltage to an output of the switching circuit according to the first and second signals to thereby provide a third signal at the output of the switching circuit; a third comparator coupled to the fourth input and the output of the switching circuit to compare the audio input signal with the third signal to generate a pulse width modulation signal; and a driver coupled to the second and third comparators to generate a fourth signal according to the second signal and the pulse width modulation signal for driving a load at an output of the class-D amplifier.