Conventional class-D amplifiers receive an analog input signal and generate a digital output signal. One advantage of a class D amplifier over a linear amplifier (e.g., a class-AB amplifier) is its high efficiency. Because the output pulses of the class-D amplifier have a fixed amplitude, the switching elements are switched either on or off, rather than operated in linear mode. One common application for a class-D amplifier is a driver for a loudspeaker.
However, most class-D amplifiers that employ standard implementations suffer from propagation delays and low power supply rejection ratio due to the switching waveforms.