Power saving during a connection detection

Patent metadata

Field	Value
Publication number	US-10459512-B2
Application number	US-201615260355-A
Country	US
Kind code	B2
Filing date	Sep 9, 2016
Priority date	Oct 8, 2009
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

An electronic device includes a receiver sense circuit configured to generate a detection signal responsive to detecting a connection to a sink device via a connector. The electronic device further includes a controller coupled to a hot plug detect (HPD) interface. The controller is configured to enable a direct current (DC) voltage source based on the detection signal received from the receiver sense circuit.

First claim

What is claimed is:

1. An electronic device comprising:
a receiver sense circuit configured to generate a detection signal responsive to detecting a connection to a sink device via a connector; and
a controller coupled to a hot plug detect (HPD) interface, the controller configured to enable a direct current (DC) voltage source based on the detection signal received from the receiver sense circuit.

2. The electronic device of claim 1 , wherein the controller is further configured to selectively control a switch to enable the DC voltage source.

3. The electronic device of claim 1 , wherein the receiver sense circuit is configured to detect the connection based on a signal received from the sink device, and wherein the receiver sense circuit is further configured to generate the detection signal in response to receiving the signal.

4. The electronic device of claim 1 , wherein the controller is further configured to detect an absence of a HPD signal and to enable the receiver sense circuit in response to detecting the absence of the HPD signal.

5. The electronic device of claim 1 , further comprising an output driver, wherein the controller is further configured to enable data transmission at the output driver in response to detecting a HPD signal subsequent to enabling the DC voltage source.

6. The electronic device of claim 1 , wherein the HPD interface is coupled to an HPD pin of the connector, and wherein the DC voltage source is selectively coupled to a voltage supply pin of the connector.

7. The electronic device of claim 1 , wherein the receiver sense circuit is coupled to a clock pin of the connector.

8. The electronic device of claim 1 , wherein the receiver sense circuit is coupled to a data pin of the connector.

9. The electronic device of claim 1 , wherein the connector comprises a high definition multimedia interface (HDMI) connector or a digital visual interface (DVI) connector.

10. The electronic device of claim 1 , wherein the DC voltage source, the receiver sense circuit and the controller are integrated within a mobile device.

11. The electronic device of claim 1 , wherein the receiver sense circuit comprises:
a first transistor;
at least one resistor coupled to the first transistor and configured to receive a signal from the sink device;
a second transistor coupled to the first transistor and configured to receive a receiver sense circuit enable signal;
a third transistor coupled to the first transistor and to ground, the third transistor configured to receive the receiver sense circuit enable signal; and
a programmable delay circuit coupled to the first transistor, to the second transistor, and to the third transistor, the programmable delay circuit configured to output the detection signal.

12. The electronic device of claim 11 , further comprising:
a switch coupled to a node and to an input of the programmable delay circuit, wherein the first transistor, the second transistor, and the third transistor are coupled to the node; and
a fourth transistor coupled to the input of the programmable delay circuit and to ground.

13. The electronic device of claim 12 , further comprising an inverter configured to receive the receiver sense circuit enable signal, wherein the switch and the fourth transistor are configured to receive an output of the inverter.

14. The electronic device of claim 11 , wherein the programmable delay circuit comprises a Schmitt trigger.

15. A method comprising:
generating, at a receiver sense circuit of a source device, a detection signal in response to detecting that a sink device is coupled to the source device via a connector; and
enabling, at a controller of the source device, a direct current (DC) voltage source in response to the detection signal.

16. The method of claim 15 , further comprising detecting that the sink device is coupled to the source device via the connector in response to receiving a signal from the sink device at the receiver sense circuit.

17. The method of claim 16 , wherein the signal is received while the DC voltage source is disabled.

18. The method of claim 15 , further comprising:
detecting a hot plug detect (HPD) signal at the controller subsequent to enabling the DC voltage source; and
disabling the receiver sense circuit in response to detecting the HPD signal.

19. The method of claim 18 , further comprising initiating data transmission from an output driver of the source device in response to detecting the HPD signal.

20. The method of claim 15 , further comprising enabling the receiver sense circuit in response to activation of an application associated with high definition output.

21. An electronic device comprising:
a receiver sense circuit configured to detect a connection to a sink device via a connector; and
a controller coupled to a hot plug detect (HPD) interface, the controller configured to disable a direct current (DC) voltage source and to enable the receiver sense circuit in response to detecting an absence of a HPD signal from the sink device.

22. The electronic device of claim 21 , wherein the controller is further configured to selectively control a switch to disable the DC voltage source.

23. The electronic device of claim 21 , further comprising an output driver, wherein the controller is further configured to disable data transmission at the output driver in response to detecting the absence of the HPD signal.

24. The electronic device of claim 21 , wherein the HPD interface is coupled to an HPD pin of the connector, and wherein the receiver sense circuit is coupled to a clock pin or a data pin of the connector.

25. The electronic device of claim 21 , wherein the connector comprises a high definition multimedia interface (HDMI) connector or a digital visual interface (DVI) connector, and wherein the sink device comprises a high definition compatible display device.

26. The electronic device of claim 21 , wherein the DC voltage source, the receiver sense circuit, and the controller are integrated within a mobile device.

27. A method comprising:
detecting, at a controller of a source device, an absence of a hot plug detect (HPD) signal from a sink device via a connector;
disabling a direct current (DC) voltage source in response to detecting the absence of the HPD signal; and
enabling a receiver sense circuit of the source device in response to detecting the absence of the HPD signal, wherein the receiver sense circuit detects whether the sink device is coupled to the source device via the connector.

28. The method of claim 27 , wherein the absence of the HPD signal is detected while the DC voltage source is enabled and the receiver sense circuit is disabled.

29. The method of claim 27 , further comprising disabling data transmission to the sink device in response to detecting the absence of the HPD signal.

30. The method of claim 27 , wherein the receiver sense circuit is enabled via a receiver sense circuit enable signal.

Assignees

• Qualcomm Inc

Inventors

• Zhong Cheng
• Dang Nam Van
• Vuong Hung Quoc
• Kong Xiaohua

Classifications

• G06F1/3281

  Power saving in PCMCIA card · CPC title

• G06F1/3278 Primary

  Power saving in modem or I/O interface · CPC title

• G06F13/4022

  using switching circuits, e.g. switching matrix, connection or expansion network (G06F13/4009 takes precedence) · CPC title

• G06F13/4081

  Live connection to bus, e.g. hot-plugging (current or voltage limitation during live insertion H02H9/004) · CPC title

• G06F11/3048

  where the topology of the computing system or computing system component explicitly influences the monitoring activity, e.g. serial, hierarchical systems · CPC title