US Patent 7816982 Switching audio power amplifier with de-noise function

The invention provides a switching audio power amplifier with de-noise function, including a first comparator, a second comparator, a logic control unit, a de-noise circuit, and a bridge circuit. The first comparator and the second comparator respectively generate the first PWM signal and the second PWM signal, and then the logic control unit performs logic operation to generate a third PWM signal and a fourth PWM signal. If the pulse width of the third PWM signal (or the fourth PWM signal) is lower than a threshold, the de-noise circuit increases the pulse width of the third PWM signal or the fourth PWM signal and outputs the fifth PWM signal and the sixth PWM signal to drive the bridge circuit. Next, the bridge circuit conducts a driving current alternately flowing to and from a load according to the firth PWM signal and the sixth PWM signal.