Method for adaptively adjusting start-up time of audio amplifier and associated system on chip

Abstract

An audio amplifier chip includes an audio amplifier, a current providing circuit, a detection circuit, and a control circuit. The audio amplifier is arranged to drive a speaker, wherein the audio amplifier has multiple differential input terminals, and a direct current (DC) blocking capacitor is coupled to one of the multiple differential input terminals. The current providing circuit is arranged to provide at least one current for charging the DC blocking capacitor. The detection circuit is coupled to a node located between the one of the multiple differential input terminals and the DC blocking capacitor, and is arranged to detect whether an external resistor of the audio amplifier chip exists according to an input voltage from the node, in order to generate a detection result. The control circuit is arranged to determine a start-up time of the audio amplifier according to the detection result.

Dependencies are inferred from the claim text.