Patent ID: 8054130
Filing Date: 2011-11-08
Classification: H03G

Abstract:
1. A method for adjusting the gain of an audio output stage that includes a class D amplifier, the method comprising: setting the gain to a nominal value, analyzing an output signal of the class D amplifier during successive clock periods, counting the number of clock periods among these successive periods during which the output signal is in a state corresponding to a saturation of the audio output stage, decreasing the gain if the number of counted clock periods reaches, before the end of a first time interval, a value corresponding to a first percentage of the total number of clock periods of the first time interval, maintaining the gain constant if, at the end of a second time interval, different from the first time interval, the number of counted clock periods corresponds to a second percentage, comprised between the first percentage and a third percentage lower than the first percentage, of the total number of clock periods of the second time interval, and increasing the gain if, at the end of the second time interval, the number of counted clock periods corresponds to a fourth percentage, lower than the third percentage, of the total number of clock periods of the second time interval.