A class D amplifier includes a noise-shaping modulator, a pulse width
modulator, and a pulse amplifier. The noise-shaping modulator receive a
pulse code modulated (PCM) signal and produces an oversampled PCM signal.
The pulse width modulator produce a pulse width modulated (PWM) signal
from the oversampled PCM signal. The pulse amplifier amplifies the PWM
signal to produce an amplified PWM signal. The PWM uses a lookup table to
convert from PCM to PWM. A compensation circuit optimizes amplifier
performance. An optional demodulator filter converts the amplified PWM
signal to an analog signal. The amplifier is ideal for integrated audio
applications.