MIC/GND detection and automatic switch

摘要

This document discusses, among other things, an audio jack detection switch configured to be coupled to first and second GND/MIC terminals of an audio jack, wherein the audio jack detection switch includes a detection circuit configured to measure an impedance on the first and second GND/MIC terminals and identify each GND/MIC terminal as either a GND pole or a MIC pole using the measured impedance, and wherein the audio jack detection switch includes a switch configured to automatically couple an identified MIC pole to a MIC connection and to automatically couple an identified GND pole to a GND connection using information from the detection circuit.

主权项

1. A system comprising:
an audio jack detection switch configured to be coupled to first, second, third, and fourth poles of a four-pole audio jack including:
a left speaker (LSPKR) pole;a right speaker (RSPKR) pole;a ground (GND) pole; anda microphone (MIC) pole; wherein the audio jack detection switch includes:
a detection circuit configured to be simultaneously coupled to the third and fourth poles of the four-pole audio jack, to measure impedances on the the third and fourth poles of the four-pole audio jack, and to identify the third pole as the GND pole or the MIC pole and the fourth pole as the GND pole or the MIC pole using the measured impedances of the third and fourth poles; anda switch configured to automatically couple the identified MIC pole to a MIC connection of a processor and to automatically couple the identified GND pole to a GND connection; and wherein the audio lack detection switch is configured to control the switch to couple the identified MIC pole to a MIC connection and the identified GND pole to a GND connection using the measured impedances.