Plug type detection

Abstract

Techniques for detecting the type of a media plug inserted into a corresponding jack. In an exemplary embodiment, the output of a first power amplifier for driving a media plug terminal, e.g., the right headphone or left headphone, is selectively coupled to a reference voltage. Measurements of the voltage at a microphone terminal of the media plug may be alternately made for the reference voltage being at a first value and a second value. In an embodiment, the first power amplifier output voltage may be varied by opening or closing a switch. Alternatively, the first power amplifier output voltage may be directly set by an input voltage to the first power amplifier. By detecting changes in the voltages measured at the microphone terminal, it may be determined whether the media plug is of a North American type or European type.

Dependencies are inferred from the claim text.