SELF-OSCILLATING CLASS-D AMPLIFIER AND SELF-OSCILLATING FREQUENCY CONTROL METHOD FOR SELF-OSCILLATING CLASS-D AMPLIFIER

摘要

A self-oscillation frequency varying element for varying the self-oscillation frequency of a self-oscillation loop of a self-oscillating class-D amplifier is placed in the self-oscillation loop. Frequency comparison, cycle comparison, or phase comparison is performed between a self-oscillation signal of the self-oscillating class-D amplifier or a signal corresponding to the self-oscillation signal and a reference frequency signal having a prescribed reference frequency. Alternatively, information corresponding to a frequency or a cycle of a self-oscillation signal of the self-oscillating class-D amplifier or a signal corresponding to the self-oscillation signal is compared with information corresponding to a prescribed reference frequency or reference cycle. The self-oscillation frequency varying element is controlled in accordance with a result of the comparison, whereby the frequency of the self-oscillation signal or the signal corresponding to the self-oscillation signal is caused to follow the frequency of the reference frequency signal.