MIC/GND detection and automatic switch

Patent metadata

Field	Value
Publication number	US-9497559-B2
Application number	US-201113189480-A
Country	US
Kind code	B2
Filing date	Jul 22, 2011
Priority date	Jul 22, 2011
Publication date	Nov 15, 2016
Grant date	Nov 15, 2016

Abstract

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.

First claim

What is claimed is:

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; and
a 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; and
a 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.

2. The system of claim 1 , wherein the four-pole audio jack includes a first audio jack configuration including:
the LSPKR pole at the first pole;
the RSPKR pole at the second pole;
the MIC pole at the third pole; and
the GND pole at the fourth pole; or
wherein the four-pole audio jack includes a second audio jack configuration including:
the LSPKR pole at the first pole;
the RSPKR pole at the second pole;
the GND pole at the third pole; and
the MIC pole at the fourth pole.

3. The system of claim 2 , wherein the detection circuit is configured to distinguish between the first and second audio jack configurations using the measured impedances.

4. A system comprising:
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 be simultaneously coupled to the first and second GND/MIC terminals of the audio jack, to measure impedances on the first and second GND/MIC terminals, and to identify each GND/MIC terminal as either a ground (GND) pole or a microphone (MIC) pole using the measured impedances; and
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; 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.

5. The system of claim 4 , wherein the audio jack includes one of:
a first audio jack configuration including:
a left speaker (LSPKR) pole at a first pole;
a right speaker (RSPKR) pole at a second pole;
the MIC pole at a third pole; and
the GND pole at a fourth pole;

a second audio jack configuration including:
the LSPKR pole at a first pole;
the RSPKR pole at a second pole;
the GND pole at a third pole; and
the MIC pole at a fourth pole; or

a third audio jack configuration including:
the LSPKR pole at a first pole;
the RSPKR pole at a second pole; and
the GND pole at a third pole.

6. The system of claim 5 , wherein the detection circuit is configured to distinguish between the first, second, and third audio jack configurations using the measured impedances.

7. A method comprising:
measuring impedances on third and fourth poles of a four-pole audio jack, including first, second, third, and fourth poles, using a detection circuit while a switch is in a first state;
identifying the third pole as a ground (GND) pole or a microphone (MIC) pole and the fourth pole as the GND pole or the MIC pole using the measured impedances of the third and fourth poles; and
controlling 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.

8. The method of claim 7 , wherein the identifying the GND pole and the MIC pole includes distinguishing between first and second audio jack configurations;
wherein the first audio jack configuration includes:
a left speaker (LSPKR) pole at a first pole;
a right speaker (RSPKR) pole at a second pole;
the MIC pole at a third pole; and
the GND pole at a fourth pole; and

wherein the second audio jack configuration includes:
a left speaker (LSPKR) pole at a first pole;
a right speaker (RSPKR) pole at a second pole;
the GND pole at a third pole; and
the MIC pole at a fourth pole.

9. The method of claim 8 , wherein the distinguishing between the first and second audio jack configurations includes using the measured impedances.

10. A method comprising:
measuring impedances on first and second GND/MIC terminals of an audio jack using a detection circuit of an audio jack detection switch coupled to the first and second GND/MIC terminals of the audio jack while a switch is in a first state;
identifying the first GND/MIC terminal as a ground (GND) pole or a microphone (MIC) and the second GND/MIC terminal as the GND pole or the MIC pole using the measured impedances of the first and second GND/MIC terminals; and
controlling the switch to couple an identified MIC pole to a MIC connection and an identified GND pole to a GND connection using the measured impedances.

11. The method of claim 10 , wherein the identifying each GND/MIC terminal as either a GND pole or a MIC pole includes distinguishing between at least one of first, second, or third audio jack configurations; and
wherein the first audio jack configuration includes:
a left speaker (LSPKR) pole at a first pole;
a right speaker (RSPKR) pole at a second pole;
the MIC pole at a third pole; and
the GND pole at a fourth pole;

wherein the second audio jack configuration includes:
the LSPKR pole at a first pole;
the RSPKR pole at a second pole;
the GND pole at a third pole; and
the MIC pole at a fourth pole; or

wherein the third audio jack configuration includes:
the LSPKR pole at a first pole;
the RSPKR pole at a second pole; and
the GND pole at a third pole.

12. The method of claim 11 , wherein the detection circuit is configured to distinguish between the first, second, and third audio jack configurations using the measured impedances.

13. The method of claim 10 , including controlling the automatically coupling an identified MIC pole to a MIC connection and an identified GND pole to a GND connection using digital logic.

14. The system of claim 4 , wherein the audio jack detection switch is configured to be coupled to a four-pole audio jack, the four-pole audio jack including:
a left speaker (LSPKR) pole;
a right speaker (RSPKR) pole;
a ground (GND) pole; and
a microphone (MIC) pole;
wherein the first GND/MIC terminal includes a first one of the GND pole or the MIC pole and the second GND/MIC terminal includes a second one of the GND pole or the MIC pole.

15. The system of claim 4 , wherein the switch is configured to enter a low power mode after automatically coupling the identified MIC pole to the MIC connection and automatically coupling the identified GND pole to a GND connection.

16. The method of claim 10 , wherein the audio jack includes a four-pole audio jack including:
a left speaker (LSPKR) pole;
a right speaker (RSPKR) pole;
a ground (GND) pole; and
a microphone (MIC) pole;
wherein the first GND/MIC terminal includes a first one of the GND pole or the MIC pole and the second GND/MIC terminal includes a second one of the

Assignees

• Prentice Seth M
• Fairchild Semiconductor

Inventors

• Prentice Seth M

Classifications

• H04R29/004 Primary

  for microphones (H04R29/007 takes precedence) · CPC title

• Y10T307/766

  Cross-Sectional Technologies · mapped topic

• H04R2420/05

  Detection of connection of loudspeakers or headphones to amplifiers · CPC title

• H04R1/02

  Casings; Cabinets {; Supports therefor;} Mountings therein (H04R1/28 takes precedence {; attachments for microphones H04R1/08; mounting of transducers in earpieces H04R1/1075}) · CPC title

• G01R27/02

  Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant (by measuring phase angle only G01R25/00) · CPC title