Patent ID: 8036399

Claim:
An audio output apparatus comprising: a system controller for outputting a digital audio signal; an audio codec coupled to said system controller for receiving the digital audio signal therefrom and for outputting an analog audio signal corresponding to the digital audio signal; a capacitor having one end coupled to said audio codec for receiving the analog audio signal therefrom; a switch unit having a first end coupled to the other end of said capacitor, a grounded second end, and a control end for receiving a control signal, said switch unit being operable to couple said first end to said second end in response to the control signal received at said control end; a switch controller coupled to said control end of said switch unit, said switch controller being triggered by a trigger signal to generate the control signal and outputting the control signal to said control end of said switch unit so that the other end of said capacitor is grounded via said switch unit; and a power circuit for supplying electric power to said system controller, said audio codec and said switch controller; wherein the trigger signal is generated by one of said system controller, said audio codec and said power circuit upon occurrence of a condition associated with pop noise, and is outputted to said switch controller before the pop noise is generated, such that said switch unit couples the other end of said capacitor to ground in response to the control signal from said switch controller and such that the pop noise is conducted to ground via said switch unit.