Method of detecting a predetermined DC Offset in an automotive audio system

摘要

The present invention relates in general to detecting a DC offset in an audio signal provided by an audio processing unit to an audio power amplifier of an automotive audio system, and, more specifically, to use of a diagnostic signal from a power amplifier to determine output conditions of the power amplifier as they are affected by a DC offset. The audio amplifier provides a clip detect signal back to the audio processing unit. The method comprises the steps of sampling the clip detect signal at a predetermined rate during a predetermined time interval to collect a predetermined number of samples. Then, a number of active clip detects are counted during the predetermined time interval. Next, the counted number is compared to a predetermined threshold and then the predetermined DC offset is detected if the counted number exceeds the predetermined threshold.