Protection circuit applied to electronic device and associated protection method

Patent metadata

Field	Value
Publication number	US-11545822-B2
Application number	US-202117228863-A
Country	US
Kind code	B2
Filing date	Apr 13, 2021
Priority date	May 2, 2018
Publication date	Jan 3, 2023
Grant date	Jan 3, 2023

Abstract

A protection circuit, and related method, for an electronic device including a first power output interface and a second power output interface is disclosed. The protection circuit includes a first switch element, coupled between a first voltage source and the first power output interface. The detection circuit being operation to detect an output voltage value of the second power output interface to generate a detection result. The first switch element, according to the detection result, connects the first voltage source to the first power output interface to allow the first power output interface to output power to an external terminal, or disconnects the first voltage source from the first power output interface.

First claim

What is claimed is:

1. A protection circuit, applied to an electronic device comprising a first voltage source, a second voltage source, a first power output interface and a second power output interface, wherein the first voltage source generates a first supply voltage to the first power output interface and the second voltage source generates a second supply voltage to the second power output interface, the protection circuit comprising:
a first switch element, coupled between the first voltage source and the first power output interface;
a second switch element, coupled between the second voltage source and the second power output interface;
a first detection circuit, coupled to the first voltage source and the first power output interface, for detecting an output voltage value of the first power output interface to generate a first detection result; and
a second detection circuit, coupled to the second voltage source and the second power output interface, for detecting an output voltage value of the second power output interface to generate a second detection result;
wherein the first switch element, according to the second detection result, connects the first voltage source to the first power output interface to allow the first power output interface to output power to an external terminal, or disconnects the first voltage source from the first power output interface.

2. The protection circuit according to claim 1 , wherein the second power output interface has multiple power supply specifications with different output voltage values.

3. The protection circuit according to claim 2 , wherein the second power output interface complies with a Universal Serial Bus (USB) type-C specification.

4. The protection circuit according to claim 1 , wherein when the second detection result indicates that the output voltage value of the second power output interface is higher than a threshold, the first switch element disconnects the first voltage source from the first power output interface; and when the second detection result indicates that the output voltage value of the second power output interface is not higher than the threshold, the first switch connects the first voltage source to the first power output interface.

5. The protection circuit according to claim 1 , wherein the second detection circuit comprises a voltage dividing circuit that performs voltage dividing on the output voltage value of the second power output interface to generate a voltage divided signal, and the second detection result is generated according to the voltage divided signal.

6. The protection circuit according to claim 5 , wherein the voltage divided signal is directly used as the second detection result, and the first switch element determines, directly according to a level of the voltage divided signal, whether to connect the first voltage source to the first power output interface or disconnect the first voltage source from the first power output interface.

7. The protection circuit according to claim 1 , wherein the second switch element, according to the first detection result, connects the second voltage source to the second power output interface to allow the second power output interface to output power to the external terminal, or disconnects the second voltage source from the second power output interface.

8. The protection circuit according to claim 7 , wherein the first power output interface and the second power output interface have multiple power supply specifications with different output values.

9. The protection circuit according to claim 8 , wherein at least one of the first power output interface and the second power output interface complies with a Universal Serial Bus (USB) type-C specification.

10. A protection method for an electronic device, the electronic device comprising a first voltage source, a second voltage source, a first power output interface and a second power output interface, wherein the first voltage source generates a first supply voltage to the first power output interface and the second voltage source generates a second supply voltage to the second power output interface, the protection method comprising:
detecting an output voltage value of the first power output interface to generate a first detection result in order to control a second switch element coupled between the second voltage source and the second power output interface;
detecting an output voltage value of the second power output interface to generate a second detection result in order to control a first switch element coupled between the first voltage source and the first power output interface; and
according to the second detection result, connecting the first voltage source to the first power output interface to allow the first power output interface to output power to an external terminal, or disconnecting the first voltage source from the first power output interface.

11. The protection method according to claim 10 , wherein the second power output interface has multiple power supply specifications with different output voltage values.

12. The protection method according to claim 11 , wherein the second power output interface complies with a Universal Serial Bus (USB) type-C specification.

13. The protection method according to claim 10 , wherein the step of, according to the second detection result, connecting the first voltage source to the first power output interface to allow the first power output interface to output power to the external terminal, or disconnecting the first voltage source from the first power output interface comprises:
when the second detection result indicates that the output voltage value of the second power output interface is higher than a threshold, disconnecting the first voltage source from the first power output interface; and
when the second detection result indicates that the output voltage value of the second power output interface is not higher than the threshold, connecting the first voltage source to the first power output interface.

14. The protection method according to claim 10 , wherein the step of detecting the output voltage value of the second power output interface to generate the second detection result comprises:
performing voltage dividing on the output voltage value of the second power output interface by a voltage dividing circuit to generate a voltage divided signal; and
generating the second detection result according to the voltage divided signal.

15. The protection method according to claim 14 , wherein the voltage divided signal is directly used as the second detection result, and the step of, according to the second detection result, connecting the first voltage source to the first power output interface to allow the first power output interface to output power to the external terminal, or disconnecting the first voltage source from the first power output interface comprises:
determining, directly according to a level of the voltage divided signal, whether to connect the first voltage source to the first power output interface or disconnect the first voltage source from the first power output interface.

16. The protection method according to claim 10 , further comprising:
according to the first detection result, connecting the second voltage source to the second power output interface to allow the second power output interface to output power to the external terminal, or disconnecting the second voltage source from the second power output interface.

17. The protection method according to claim 10 , wherein the first power output int

Assignees

• Mediatek Inc

Inventors

• Chuang Tsui-Chuan
• Liu Ming-Ruei
• Chiang Dien-Shen
• Kao Chien-Tai

Classifications

• H02H3/048 Primary

  Checking overvoltage diverters · CPC title

• G06F1/305

  in the event of power-supply fluctuations · CPC title

• G06F1/28

  Supervision thereof, e.g. detecting power-supply failure by out of limits supervision · CPC title

• H02H3/20

  responsive to excess voltage · CPC title

• G06F1/263 Primary

  Arrangements for using multiple switchable power supplies, e.g. battery and AC (G06F1/30 takes precedence) · CPC title