| 摘要 |
<p>A portable computer system includes an audio circuit and a common audio input socket coupled to the audio circuit. This audio circuit has a controller and two amplifiers. Two types of external audio devices is to be coupled to the common audio input socket. The controller controls the two amplifiers alternately depending upon the audio type of the external audio device coupled to the common audio input socket. In a preferred embodiment, a first amplifier is provided for amplifying stereo audio signals and a second amplifier for amplifying a mono audio signal. When the controller detects a mono audio device, the microcontroller disables the first amplifier. Detecting a stereo audio device, the controller disables the second amplifier.</p> |
