Switching amplifier

A switching amplifier comprising:

• a delta-sigma modulation circuit that is a circuit for performing delta-sigma modulation of an input signal and outputting a quantized signal, the delta-sigma modulation circuit including
• a group of integrators that consists of a plurality of integrators connected in a cascade arrangement and receives the input signal at a first-stage integrator, and
• a quantizer that quantizes a signal based on an output signal of the group of integrators and outputs a quantized signal,
• the delta-sigma modulation circuit that feeds back a signal based on the quantized signal to the first-stage integrator;
• a pulse amplifier that has a switching element and performs pulse amplification of the quantized signal by switching the switching element according to the quantized signal;
• an amplitude level detector that detects an amplitude level of the input signal;
• and
• a sampling frequency adjuster that varies a sampling frequency of the quantizer according to a detection result of the amplitude level detector.