Programmable VBUS discharge in USB power delivery

Patent metadata

Field	Value
Publication number	US-10599597-B2
Application number	US-201815983596-A
Country	US
Kind code	B2
Filing date	May 18, 2018
Priority date	Mar 12, 2018
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

Techniques for voltage discharge from a USB Power Delivery (USB-PD) VBUS line are described herein. In an example embodiment, an integrated circuit comprises a discharge control logic coupled to a first discharge circuit and to a second discharge circuit. The first discharge circuit configured to couple to a power source node on the VBUS line. The second discharge circuit configured to couple to an output node on the VBUS line. The discharge control logic is configured to independently control the first discharge circuit and the second discharge circuit to discharge the voltage on the VBUS line.

First claim

What is claimed is:

1. An integrated circuit (IC) for controlling power transfer on a Universal Serial Bus (USB) voltage (VBUS) line, the IC comprising:
a USB Power Delivery (USB-PD) controller disposed in a semiconductor die, wherein the USB-PD controller comprises:
a first discharge circuit disposed on the semiconductor die, wherein the first discharge circuit is to couple to a power source node on the VBUS line and to drive current, at a first programmable drive-strength, from the VBUS line through the USB-PD controller to a USB ground line;
a second discharge circuit disposed on the semiconductor die, wherein the second discharge circuit is to couple to an output node on the VBUS line and to drive current, at a second programmable drive-strength, from the VBUS line through the USB-PD controller to the USB ground line; and
a discharge control logic coupled to the first discharge circuit and to the second discharge circuit, wherein the discharge control logic is to independently control the first discharge circuit and the second discharge circuit to discharge voltage on the VBUS line;
wherein the discharge control logic is to generate multi-bit control signals that are applied to the first discharge circuit and the second discharge circuit to control the first programmable drive-strength and the second programmable drive-strength, respectively.

2. The integrated circuit of claim 1 , wherein the power source node is disposed on one side of a power switch on the VBUS line and the output node is disposed on the other side of the power switch on the VBUS line.

3. The integrated circuit of claim 1 , further comprising:
a first input pin coupled to the first discharge circuit;
a second input pin coupled to the second discharge circuit; and
one or more ground output pins coupled to the first discharge circuit and the second discharge circuit.

4. The integrated circuit of claim 1 , further comprising firmware instructions to control a drive strength schedule that is applied by the discharge control logic to at least one of the first discharge circuit and second discharge circuit.

5. The integrated circuit of claim 1 , wherein the USB-PD controller further comprises a voltage threshold detector logic coupled to the discharge control logic, wherein the voltage threshold detector logic is to monitor the voltage on the VBUS line at the power source node and at the output node.

6. The integrated circuit of claim 5 , wherein the voltage threshold detector logic is to monitor the voltage on the VBUS line with respect to multiple voltage levels.

7. The integrated circuit of claim 1 , wherein the USB-PD controller further comprises protection logic coupled to the discharge control logic, wherein the protection logic is to monitor a discharge rate of the voltage on the VBUS line.

8. The integrated circuit of claim 7 , wherein the protection logic is to protect against discharging a live supply voltage on the VBUS line.

9. The integrated circuit of claim 1 , wherein each of the first discharge circuit and the second discharge circuit comprises one or more drain-extended field-effect transistors (DEFETs).

10. The integrated circuit of claim 1 , wherein the discharge control logic is to control the first discharge circuit to discharge the voltage on the VBUS line at a first discharge rate and to control the second discharge circuit to discharge the voltage on the VBUS line at a second discharge rate.

11. The integrated circuit of claim 1 , wherein the discharge control logic is to stop discharging the voltage on the VBUS line at a non-zero voltage level.

12. The integrated circuit of claim 1 , wherein the USB-PD controller further comprises:
a voltage threshold detector logic to monitor the voltage on the VBUS line;
a current sense detector logic to monitor current returned on the USB ground line; and
a fault detector logic coupled to the current sense detector and to the voltage threshold detector, wherein the fault detector logic is to detect one or more fault events on the VBUS line.

13. An apparatus comprising:
a Universal Serial Bus (USB) Type-C connector, the USB Type-C connector comprising a voltage (VBUS) line and a USB ground line; and
an integrated circuit (IC) controller disposed in a semiconductor die and coupled to control power transfer on the VBUS line, the IC controller comprising:
a first discharge circuit disposed on the semiconductor die, wherein the first discharge circuit is coupled to a power source node on the VBUS line and is to drive current, at a first programmable drive-strength, from the VBUS line through the IC controller to the USB ground line;
a second discharge circuit disposed on the semiconductor die, wherein the second discharge circuit is coupled to an output node on the VBUS line and is to drive current, at a second programmable drive-strength, from the VBUS line through the IC controller to the USB ground line; and
a discharge control logic coupled to the first discharge circuit and to the second discharge circuit, wherein the discharge control logic is to independently control the first discharge circuit and the second discharge circuit to discharge voltage on the VBUS line;
wherein the discharge control logic is to generate multi-bit control signals that are applied to the first discharge circuit and the second discharge circuit to control the first programmable drive-strength and the second programmable drive-strength, respectively.

14. The apparatus of claim 13 , further comprising a power switch coupled on the VBUS line, wherein the power source node is disposed on one side of the power switch and the output node is disposed on the other side of the power switch.

15. The apparatus of claim 13 , wherein the IC controller comprises:
a first input pin that couples the first discharge circuit to the power source node;
a second input pin that couples the second discharge circuit to the output node; and
one or more ground output pins that couple the first discharge circuit and the second discharge circuit to the USB ground line.

16. The apparatus of claim 13 , wherein the IC controller is configured to control transfer of power over the VBUS line in accordance with a USB Power Delivery (USB-PD) specification.

17. The apparatus of claim 13 , wherein the IC controller is configured to control a discharge rate of the voltage on the VBUS line.

18. The apparatus of claim 13 , wherein the IC controller is configured to monitor the voltage on the VBUS line with respect to multiple voltage levels.

19. The apparatus of claim 13 , wherein the apparatus is one of a personal computer (PC) power adapter, a mobile phone charger, a wall socket, a car charger, and a power bank.

Assignees

• Cypress Semiconductor Corp

Inventors

• Mattos Derwin
• Arulappan Godwin Gerald
• Raza Syed
• Nayak Anup
• Gupta Sumeet
• Mandagulathur Venkat

Classifications

• G06F1/3215

  Monitoring of peripheral devices · CPC title

• G06F1/266 Primary

  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

• G06F1/26

  Power supply means, e.g. regulation thereof (for memories G11C) · CPC title

• G06F2213/0042

  Universal serial bus [USB] · CPC title

• G06F13/385 Primary

  for adaptation of a particular data processing system to different peripheral devices · CPC title