The objective of the invention is to provide a class D amplifier that can
reduce aliasing noise. The class D amplifier has D/A converter 10 that
operates at the first sampling frequency, and PWM driver 3 that receives
the output from D/A converter 10. Said PWM driver 3 operates at the
second sampling frequency synchronized to the first sampling frequency.
The second sampling frequency can be correlated to the delta wave
frequency of the PWM driver. Also, synchronization of said first sampling
frequency and said second sampling frequency can be carried out with one
of said frequencies being an integer multiple of the other.