PWM (pulse width modulation) audio power amplifier

The invention discloses a PWM (pulse width modulation) audio power amplifier comprising a linear isolating module, a PWM amplifying modulating thick-film, a suspending drive module, a high-tension power bridge and a Butterworth filter. The audio signal input end is connected with the input end of the linear isolating module. The output end of the Butterworth filter is connected with a load of the amplifier. supplied power of the amplifier passes a bridge rectifier circuit, an LPF (low pass filter) and a dual-closed ring APFC (active power factor correction) circuit and is then transmitted to the PWM amplifying modulating thick-film, the suspending drive module, the high-tension power bridge and the Butterworth filter; the PWM amplifying modulating thick-film, the suspending drive module, the high-tension power bridge and the Butterworth filter form a class-D bridge power amplifier topological structure. The amplifier integrating signal amplifying, driving, amplified power output and power supply has the advantages that efficiency of the amplifier is greatly improved, service efficiency of the power supply is greatly improved, and electromagnetic interference of equipment is greatly improved.