Multiphase clamp coupled-buck converter and magnetic integration

• US 6,784,644 B2
• Filed: 02/22/2002
• Issued: 08/31/2004
• Est. Priority Date: 02/22/2001
• Status: Expired due to Fees

• Current Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Original Assignee: Virginia Tech Intellectual Properties, Inc. (Virginia Polytechnic Institute and State University)
• Inventors: Xu, Peng, Yao, Kaiwei, Ye, Mao, Lee, Fred C., Wei, Jia
• Primary Examiner(s): HAN, YOUNGHUIE JESSICA
• Application Number:
  US10/079,819
• Publication Number:
  US 20020118000A1
• Time in Patent Office: 921 Days
• Field of Search: 363/39, 363/89, 363/125, 363/56.12, 323/222, 323/225, 323/247, 323/255, 323/259, 323/250, 323/282, 323/284, 361/91.7, 315/209.R
• US Class Current: 323/225
• CPC Class Codes: H02M 1/0064 Magnetic structures combining different functions, e.g. storage, filtering or transformation
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

Voltage regulation, transient response and efficiency of a voltage regulator module (VRM) is improved where short duty cycles are necessitated by large differentials of input and output voltage by including at least one clamping of a tap of an inductance in series with an output of each of a plurality of parallel branches or phases which are switched in a complementary fashion or providing coupling between inductors of respective phases. Such coupling between inductors is achieved in a small module with an integrated magnetic structure. Reduced component counts are achieved while deriving built-in input and output filters. Principals of the invention can be extended to isolation applications and push-pull forward converts, in particular. A lossless clamping circuit is also provided allowing spike currents to be suppressed while returning power to the output of the VRM.

Claims

1. A voltage regulator circuit including

a plurality of branches switched in a complementary manner to define a plurality of phases,

an inductor connected in series with an output of each said phase,

a clamping circuit connected to a tap of said inductor and,

means for providing coupling between respective inductors of respective neighboring ones of said plurality of phases.

2. A circuit as recited in claim 1, wherein said clamping circuit is a passive clamping circuit.

3. A circuit as recited in claim 1, wherein said clamping circuit is an active clamping circuit.

4. A circuit as recited in claim 1, wherein said clamping circuit is a lossless clamping circuit.

5. A circuit as recited in claim 1, wherein said means for providing coupling includes formation of portions of said inductors for respective neighboring phases as coils on a common core.

6. A circuit as recited in claim 5, wherein said core is an E-I core having an air gap in a central leg.

7. A circuit as recited in claim 5, wherein said coils formed on a common core are in the form of a transformer and inductors.

8. A circuit as recited in claim 7, further including

a push-pull forward converter, and

a current doubler rectifier circuit.

9. A circuit as recited in claim 1, wherein portions of said inductors, said means for coupling and said clamping circuit are configured as filters.

10. A circuit as recited in claim 1, wherein said inductors are configured as tapped inductors.

11. An electronic device comprising, in combination,

an integrated circuit chip and a voltage regulator module, wherein said voltage regulator module includes

a plurality of branches switched in a complementary manner to define a plurality of phases,

an inductor connected in series with an output of each said phase,

a clamping circuit connected to a tap of said inductor, and

means for proving coupling between respective inductors of respective ones of said plurality of phases.

12. A device as recited in claim 11, wherein said clamping circuit is a passive clamping circuit.

13. A device as recited in claim 11, wherein said clamping circuit is an active clamping circuit.

14. A device as recited in claim 11, wherein said clamping circuit is a lossless clamping circuit.

15. A device as recited in claim 11, wherein said means for providing coupling includes formation of portions of said inductors for respective neighboring phases as coils on a common core.

16. A device as recited in claim 15, wherein said core is an E-I core having an air gap in a central leg.

17. A device as recited in claim 15, wherein said coils formed on a common core are in the form of a transformer and inductors.

18. A device as recited in claim 17, further including

a push-pull forward converter, and

a current doubler rectifier circuit.

19. A device as recited in claim 11, wherein portions of said inductors, said means for coupling and said clamping circuit are configured as filters.

20. A device as recited in claim 11, wherein said inductors are configured as tapped inductors.

21. A device as recited in claim 11, wherein said integrated circuit device is a microprocessor.

22. A voltage regulator circuit comprising

an inductor connected in series with an output, said inductor having first and second inductively coupled windings,

a first switch connected in series between said first and second inductively coupled windings,

a second switch connected between a node between said first switch and said second inductively coupled winding and a reference voltage, and

a lossless clamp circuit connected across said first inductively coupled winding and said reference voltage.

23. A circuit as recited in claim 22 wherein said lossless clamp circuit comprises

two series connected diodes, and

a capacitor.

24. A circuit as recited in claim 22 having

a plurality of branches switched in a complementary manner to define a plurality of phases,

means for proving coupling between respective inductors of respective ones of said plurality of phases.

25. An electronic device comprising, in combination,

an integrated circuit chip and a voltage regulator module, wherein said voltage regulator module includes

an inductor connected in series with an output, said inductor having first and second inductively coupled windings,

a first switch connected in series between said first and second inductively coupled windings,

a second switch connected between a node between said first switch and said second inductively coupled winding and a reference voltage, and

a lossless clamp circuit connected across said first inductively coupled winding and said reference voltage.

26. A device as recited in claim 25 wherein said lossless clamp circuit comprises

two series connected diodes, and

a capacitor.

27. A device as recited in claim 25 having

a plurality of branches switched in a complementary manner to define a plurality of phases,

means for proving coupling between respective inductors of respective ones of said plurality of phases.