AUDIO POWER AMPLIFIER USING VIRTUAL GROUND AND METHOD OF PROCESSING SIGNAL IN THE AUDIO POWER AMPLIFIER

摘要

An audio power amplifier provides a virtual ground to reduce power on/off noise and a method for processing a signal in the audio power amplifier. The audio power amplifier includes a switching amplifier to amplify a small output pulse width modulation (PWM) signal so as to generate a large output PWM signal, a pulse generating unit to generate a pulse signal having the same level as that of the PWM signal level, a first low pass filter to allow the large output PWM signal amplified by the switching amplifier to be low-pass filtered so as to restore the PWM signal to an audio signal, and a second low pass filter to allow the pulse signal generated by the pulse signal generating unit to be low-pass filtered so as to convert the pulse signal into a virtual ground voltage with respect to the restored audio signal.