| 摘要 |
<p>A normally-open pushbutton switch is coupled to and cooperates with a pair of MOSFETs to provide a power on switch function for a personal audio device that does not require power to be drawn from a power source to monitor the pushbutton switch while awaiting operation of the pushbutton switch to cause the personal audio device to be powered on. A controller of a personal audio device, on multiple occasions, monitors a conductor by which it is able to be coupled to another device for the end to an instance of signal activity, and following the end of signal activity, injects a current into the conductor and measures the resulting voltage to calculate an adaptive threshold voltage and to compare the measured voltage to the adaptive threshold to determine at least whether or not the conductor of the personal audio device is coupled to another device.</p> |
