Apparatus, systems and methods for detecting insertion or removal of an audio accessory from an electronic device

1. An electronic device for detecting an audio accessory, comprising:

an audio jack comprising:

an end terminal configured to electrically contact and send audio information to a tip connector of an audio plug of the audio accessory when the audio plug of the audio accessory is inserted into the audio jack; and

a detection terminal spaced apart from the end terminal and positioned within the audio jack to electrically contact the tip connector of the audio plug of the audio accessory when the audio plug of the audio accessory is inserted into the audio jack; and

a detection circuit comprising a first terminal coupled to the end terminal and a second terminal coupled to the detection terminal via a switch, the detection circuit configured to:

activate the switch to couple the second terminal to the detection terminal;

generate a signal indicative of insertion of the audio plug of the audio accessory into the audio jack when the switch is activated and first terminal and the second terminal are shorted by the tip connector of the audio plug electrically contacting the end terminal and the detection terminal; and,

after generating the signal, deactivate the switch to decouple the second terminal from the detection terminal to prevent the detection circuit from interfering with a quality of audio being sent to the audio accessory.

2. The electronic device of claim 1 , wherein the detection circuit further comprises a voltage source coupled to the second terminal via the switch, wherein the detection circuit is configured to activate the switch to apply a bias voltage to the second terminal and generate the signal indicative of insertion of the audio plug of the audio accessory into the audio jack when the bias voltage is not detected at the second terminal, and wherein the bias voltage is outside of an output voltage range of an audio amplifier of the electronic device.

3. The electronic device of claim 2 , wherein the detection circuit is further configured to generate a further signal indicative of removal of the audio plug of the audio accessory from the audio jack when the switch remains activated and the bias voltage is detected at the second terminal.

4. The electronic device of claim 1 , wherein the detection circuit comprises a current source coupled to the second terminal via the switch to provide current to an audio amplifier of the electronic device coupled to the first terminal when the switch is activated and the first and second terminals are shorted by the tip connector of the audio plug electrically contacting the end terminal and the detection terminal; and a current detector configured to detect the current provided to the audio amplifier and generate the signal indicative of insertion of the audio plug of the audio accessory into the audio jack when the switch is activated and the first terminal and second terminal are shorted by the tip connector of the audio plug electrically contacting the end terminal and the detection terminal.

5. The electronic device of claim 4 , wherein the detection circuit is further configured to detect a voltage swing at the second terminal when the switch is activated and the first terminal and second terminal are no longer shorted by the tip connector of the audio plug electrically contacting the end terminal and the detection terminal and generate a further signal indicative of removal of the audio plug of the audio accessory from the audio jack when the voltage swing is detected.

6. The electronic device of claim 1 , wherein the detection circuit is configured to periodically activate the switch to couple the second terminal to the detection terminal.

7. The electronic device of claim 6 , wherein the detection circuit is further configured to, after generating the signal indicative of insertion of the audio plug of the audio accessory into the audio jack, generate a further signal indicative of removal of the audio plug of the audio accessory from the audio jack when the switch is activated and the first terminal and the second terminal are no longer shorted by the tip connector of the audio plug electrically contacting the end terminal and the detection terminal.

8. The electronic device of claim 1 , wherein the audio jack comprises a socket having a first side and a second side, and wherein the end terminal is positioned on the first side and the detection terminal is positioned on the second side opposite the end terminal.

9. The electronic device of claim 1 , wherein the end terminal and the detection terminal are at or near a tip-end of the socket of the audio jack.

10. The electronic device of claim 1 , wherein the audio jack comprises:

a ring 1 terminal positioned on a first side of the socket and configured to electrically contact with a ring 1 contact of the audio plug of the audio accessory;

a ring 2 terminal positioned on one of a first side and the second side of the socket and configured to electrically contact with a ring 2 contact of the audio plug of the audio accessory; and

a sleeve terminal positioned on one of the first side and the second side of the socket and configured to electrically contact with a sleeve contact of the audio plug of the audio accessory.