Patent ID: 7809144
Filing Date: 2010-10-05
Classification: G06F,H01R

Abstract:
1. An audio input-output module comprising: a plurality of plug-in receptors, each of the plurality of plug-in receptors having a corresponding plurality of switches that have a first state when coupled to a plug connector and a second state when plug-in receptor is decoupled from the plug connector; an impedance network, operably coupled to the plurality of switches, for producing a plug-in signal in response to a supply signal that varies based on whether each of the plurality of switches is in the first state or the second state; a reference signal generator for generating a reference signal having a plurality of reference signal values; a comparator, operably coupled to the plug-in signal and the reference signal, for generating a detection signal when the plug-in signal compares favorably to the reference signal, wherein the comparator includes a first input current and a second input current and wherein the comparator further includes an offset cancellation module for automatically balancing the first input current and the second input current that includes a first offset current generator for generating a first offset current having a plurality of first offset current values; a processing module, operably coupled to the detection signal, the first offset current generator and the reference signal, for detecting which of the plurality of plug-in receptors have a plug connector coupled thereto, and further for controlling the first offset current generator to generate a sequence of first offset current values, and controlling the first offset current generator to hold the first offset current value when the first input current compares favorably to the second input current; and a switch network for selectively coupling an audio output to one of the plurality of plug-in receptors.