Faulty current sense line detection in multiphase voltage regulators

Patent metadata

Field	Value
Publication number	US-10693361-B2
Application number	US-201816051762-A
Country	US
Kind code	B2
Filing date	Aug 1, 2018
Priority date	Aug 1, 2018
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A multiphase voltage regulator includes a plurality of power stages, a plurality of current sense circuits, a controller and a current sense interface running between the controller and one or more of the current sense circuits. The current sense interface includes a separate line for each current sense circuit coupled to the current sense interface and which is configured to support single-ended or differential current sense. The regulator also includes a plurality of pullup circuits, each of which is connected to one of the current sense interface lines and has a higher impedance than the line to which it is connected. A fault detection circuit of the controller determines if an individual one of the current sense interface lines has an open fault, based on the pullup circuit connected to the line with the open fault pulling up the voltage on the line by more than a predetermined amount.

First claim

What is claimed is:

1. A multiphase voltage regulator, comprising:
a plurality of power stages, each of which is configured to deliver a phase current to a load;
a plurality of current sense circuits, each of which is configured to provide a current sense signal representative of the phase current delivered to the load by the power stage coupled to the current sense circuit;
a controller configured to control the plurality of power stages to regulate an output voltage provided to the load, based at least partly on the current sense signals provided by the current sense circuits;
a current sense interface running between the controller and one or more of the current sense circuits, the current sense interface comprising a separate line for each current sense circuit coupled to the current sense interface and which is configured to support single-ended or differential current sense; and
a plurality of pullup circuits, each of which is connected to one of the current sense interface lines and has a higher impedance than the line to which the pullup circuit is connected,
wherein the controller comprises a fault detection circuit configured to determine if an individual one of the current sense interface lines has an open fault, based on the pullup circuit connected to the line with the open fault pulling up the voltage on the line by more than a predetermined amount.

2. The multiphase voltage regulator of claim 1 , wherein the current sense interface comprises a separate single current sense line for each current sense circuit coupled to the current sense interface and which is configured to support single-ended current sense, and wherein a pullup circuit is connected to a corresponding one of the single current sense lines.

3. The multiphase voltage regulator of claim 1 , wherein the current sense interface comprises a separate current sense line and a separate current reference line for each current sense circuit coupled to the current sense interface and which is configured to support differential current sense, and wherein a pullup circuit is connected to a corresponding one of the current sense lines.

4. The multiphase voltage regulator of claim 1 , wherein the current sense interface comprises a separate current sense line and a separate current reference line for each current sense circuit coupled to the current sense interface and which is configured to support differential current sense, and wherein a pullup circuit is connected to a corresponding one of the current reference lines.

5. The multiphase voltage regulator of claim 1 , wherein the current sense interface comprises a separate current sense line and a separate current reference line for each current sense circuit coupled to the current sense interface and which is configured to support differential current sense, and wherein a first pullup circuit is connected to a corresponding one of the current sense lines and a second pullup circuit is connected to a corresponding one of the current reference lines.

6. The multiphase voltage regulator of claim 1 , wherein at least one of the current sense circuits is a DCR (direct current resistance) sensor comprising an RC network coupled in parallel with an inductor, and wherein the current sense interface is configured to support differential current sense and comprises a current sense line coupled to a first terminal of the capacitor of the RC network and a current reference line coupled to a second terminal of the capacitor.

7. The multiphase voltage regulator of claim 6 , wherein a pullup circuit is connected to the current sense line.

8. The multiphase voltage regulator of claim 6 , wherein a pullup circuit is connected to the current reference line.

9. The multiphase voltage regulator of claim 6 , wherein a first pullup circuit is connected to the current sense line and a second pullup circuit is connected to the current reference line.

10. The multiphase voltage regulator of claim 1 , wherein at least one of the current sense circuits is a single-ended output current mirror sensor integrated with a corresponding power stage, wherein the current sense interface comprises a single current sense line configured to support single-ended current sense, and wherein a pullup circuit is connected to the single current sense line.

11. The multiphase voltage regulator of claim 1 , wherein at least one of the current sense circuits is a differential output current mirror sensor integrated with a corresponding power stage, and wherein the current sense interface is configured to support differential current sense and comprises a current sense line connected to a first output node of the differential output current mirror sensor and a current reference line connected to a second output node of the differential output current mirror sensor.

12. The multiphase voltage regulator of claim 11 , wherein a pullup circuit is connected to the current sense line.

13. The multiphase voltage regulator of claim 11 , wherein a pullup circuit is connected to the current reference line.

14. The multiphase voltage regulator of claim 11 , wherein a first pullup circuit is connected to the current sense line and a second pullup circuit is connected to the current reference line.

15. The multiphase voltage regulator of claim 1 , wherein at least one of the pullup circuits comprises a discrete pullup resistor located in close proximity to the controller.

16. The multiphase voltage regulator of claim 1 , wherein at least one of the pullup circuits is integrated with the controller.

17. The multiphase voltage regulator of claim 16 , wherein the at least one pullup circuit is a pullup resistor, a transistor or a current source.

18. The multiphase voltage regulator of claim 16 , further comprising a switch coupled to the at least one pullup circuit and configured to disconnect the at least one pullup circuit from the current sense interface when the multiphase voltage regulator is regulating the output voltage provided to the load.

19. The multiphase voltage regulator of claim 18 , wherein the controller is configured to ignore voltage measurements taken from the current sense interface when the at least one pullup circuit is enabled by the switches and the multiphase voltage regulator is regulating the output voltage provided to the load.

20. The multiphase voltage regulator of claim 1 , wherein the fault detection circuit comprises a comparator circuit configured to compare voltage measurements taken over the current sense interface to a threshold detection voltage to determine if an individual one of the current sense interface lines has an open fault.

21. The multiphase voltage regulator of claim 1 , wherein the controller comprises an ADC (analog-to-digital voltage regulator) configured to convert analog voltage measurements over the current sense interface to corresponding digital values, and wherein the fault detection circuit is configured to determine if an individual one of the current sense interface lines has an open fault based on whether the digital values fall outside a predetermined range.

22. The multiphase voltage regulator of claim 1 , wherein the fault detection circuit is configured to determine if an individual one of the current sense interface lines has an open fault during a startup mode of the multiphase voltage regulator.

23. The multiphase voltage regulator of claim 1 , wherein the multiphase voltage regulator is configured to begin regulating the output voltage provid

Assignees

• Infineon Technologies Austria Ag

Inventors

• Guo Jinghong
• Hu Harrison
• Ng Tim
• Oddicini Mattia
• Tang Benjamim
• Zojer Herbert

Classifications

• G01R31/42 Primary

  AC power supplies · CPC title

• H02M3/1586

  switched with a phase shift, i.e. interleaved · CPC title

• H02M1/0009

  Devices or circuits for detecting current in a converter · CPC title

• H02M1/325

  with means for allowing continuous operation despite a fault, i.e. fault tolerant converters · CPC title

• G01R31/54

  Testing for continuity · CPC title