Audio activity detection circuit to increase battery life in portable computers

摘要

A power management system for a computer system having an audio circuit which generates an audio output signal. An activity detection circuit senses audio signal activity on the analog audio signal. The power management system maintains power to at least the audio circuit when activity is detected on the analog audio circuit by the activity detection circuit. The power management system causes the audio circuit to enter a power conservation mode when no activity is detected by the audio detection circuit on the audio analog signal for a predetermined amount of time.