USB Type-C port short protection

Patent metadata

Field	Value
Publication number	US-11784485-B2
Application number	US-202117552926-A
Country	US
Kind code	B2
Filing date	Dec 16, 2021
Priority date	Feb 27, 2019
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

A short circuit protection circuit may comprise a first configuration channel line extending from a first connector, a first resistor connected to the first configuration channel line; a voltage divider connected to a junction point on the first configuration channel line, the voltage divider comprising a second resistor and a thermistor, and a field effect transistor (FET) comprising a source, gate, and drain. The thermistor may be connected to a ground line. The drain of the FET may be connected to the first resistor, the source of the FET may be connected to the ground line, and the gate of the FET may be connected to a second junction point between the second resistor and thermistor of the voltage divider.

First claim

The invention claimed is:

1. A short circuit protection circuit, the short circuit protection circuit comprising:
a first configuration channel line extending from a first pin of an upstream facing universal serial bus (USB) type-C port;
a voltage divider connected to a first junction point on the first configuration channel line, the voltage divider comprising a resistor and a thermistor, wherein the thermistor is connected to a ground line;
a transistor directly connected to a second junction point between the resistor and the thermistor of the voltage divider, with no intermediary connection between the transistor and the second junction point, the transistor configured to turn on respondent to an output voltage at the second junction point being above a threshold value; and
a controller directly connected to the second junction point, with no intermediary connection between the controller and the second junction point, the controller configured to read the output voltage at the second junction point when there is voltage in the first configuration channel line and the second junction point.

2. The short circuit protection circuit of claim 1 , wherein a voltage is present at the first pin when the transistor is on.

3. The short circuit protection circuit of claim 1 , further comprising:
a diode positioned on the first configuration channel line between the resistor on the first configuration channel line and the first junction point.

4. The short circuit protection circuit of claim 1 , wherein the output voltage is lower at the second junction point when the thermistor is at a higher temperature than when the thermistor is at a lower temperature.

5. The short circuit protection circuit of claim 1 , wherein the voltage divider outputs there is no output voltage at the second junction point when the thermistor is above a predefined temperature.

6. The short circuit protection circuit of claim 1 , further comprising a capacitor, wherein the capacitor is connected on a first end to the first junction point on the first configuration channel line and to the ground line on a second end.

7. The short circuit protection circuit of claim 6 , wherein the capacitor stabilizes the voltage at the first junction point.

8. The short circuit protection circuit of claim 1 , wherein the transistor is configured to turn off when the voltage at the second junction point is below the threshold value.

9. The short circuit protection circuit of claim 8 , wherein power is delivered over a power supply line extending from another pin when transistor is on and no power is delivered over the power supply line when the transistor is off.

10. The short circuit protection circuit of claim 1 , wherein the transistor is a field-effect transistor.

11. The short circuit protection circuit of claim 1 , wherein the transistor is a metal-oxide-semiconductor field-effect transistor (MOSFET).

12. The short circuit protection circuit of claim 1 , further comprising a second resistor connected to the first configuration channel line, wherein the second resistor is connected to the drain of the transistor.

13. The short circuit protection circuit of claim 1 , wherein the controller is further configured to calculate at least one of a temperature or a resistance of the thermistor based at least in part on the output voltage.

14. A short circuit protection circuit, the short circuit protection circuit comprising:
a first configuration channel line extending from a first pin of an upstream facing universal serial bus (USB) type-C port;
a second configuration channel line extending from a second pin of the upstream facing USB type-C port;
a voltage divider connected to a first junction point on the first and second configuration channel lines, the voltage divider comprising a resistor and a thermistor, wherein the thermistor is connected to a ground line; and
a transistor directly connected to a second junction point between the resistor and the thermistor of the voltage divider, with no intermediary connection between the transistor and the second junction point, the transistor configured to turn on respondent to an output voltage at the second junction point being above a threshold value; and
a controller directly connected to the second junction point, with no intermediary connection between the controller and the second junction point, the controller configured to read the output voltage at the second junction point when there is voltage in the first configuration channel line and the second junction point.

15. The short circuit protection circuit of claim 14 , wherein a voltage is present at the first pin when the transistor is on.

16. The short circuit protection circuit of claim 14 , further comprising:
a diode positioned on the first configuration channel line between a resistor on the first configuration channel line and the first junction point; and
a diode positioned on the second configuration channel line between a resistor on the second configuration channel line and the first junction point.

17. The short circuit protection circuit of claim 14 , wherein the output voltage is lower at the second junction point when the thermistor is at a higher temperature than when the thermistor is at a lower temperature.

18. The short circuit protection circuit of claim 14 , wherein there is no output voltage at the second junction point when the thermistor is above a predefined temperature.

19. The short circuit protection circuit of claim 14 , further comprising a capacitor, wherein the capacitor is connected on a first end to the first junction point and to the ground line on a second end.

20. The short circuit protection circuit of claim 14 , wherein the controller is further configured to calculate at least one of a temperature or a resistance of the thermistor based at least in part on the output voltage.

Assignees

• Google Llc

Inventors

• Ding Yao
• Li Hui

Classifications

• G06F1/266

  Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips · CPC title

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H02H5/042

  using temperature dependent resistors · CPC title

• H02H3/085 Primary

  making use of a thermal sensor, e.g. thermistor, heated by the excess current (also responsive to the temperature of the protected device H02H5/041, thermal images H02H6/00) · CPC title

• H02H3/08 Primary

  responsive to excess current (responsive to abnormal temperature caused by excess current H02H5/04) · CPC title