Coupled-inductor power-supply controller for operating a power supply in a reduced-power-dissipation mode

Patent metadata

Field	Value
Publication number	US-9755520-B2
Application number	US-65198510-A
Country	US
Kind code	B2
Filing date	Jan 4, 2010
Priority date	May 23, 2006
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

An embodiment of a power-supply controller includes first and second circuits. The first circuit is operable to cause a first current to flow through a first phase of a power supply. And the second circuit is operable to cause the second phase of the power supply to operate in a reduced-power-dissipation mode for at least a portion of a time period during which a second current magnetically induced by the first current flows through the second phase.

First claim

What is claimed is:

1. A power-supply controller, comprising:
a first circuit configured to cause a first current to flow through a first phase of a power supply; and
a second circuit configured to cause a second phase of the power supply to operate in a reduced-power-dissipation mode by closing a reference-side switch of the second phase for no longer than a portion of a time period during which a second current magnetically induced by the first current flows through the second phase, the portion of the time period being less than the time period.

2. The power-supply controller of claim 1 wherein the first circuit is further configured to cause the first current to flow by closing a supply-side switch of the first phase.

3. The power-supply controller of claim 1 wherein the first circuit is further configured to cause the first current to flow by closing a first supply-side switch of the first phase and opening a first reference-side switch of the first phase.

4. The power-supply controller of claim 1 wherein the second circuit is further configured to cause the second phase to operate in the reduced-power-dissipation mode by activating a conduction path in parallel with the reference-side switch of the second phase.

5. The power-supply controller of claim 1 wherein the second circuit is further configured to cause the second phase to exit the reduced-power-dissipation mode by deactivating a conduction path in parallel with the reference-side switch of the second phase.

6. A power-supply controller, comprising:
a first circuit configured to open and close a first circulation element of a first power-supply phase;
a second circuit configured to lower and to raise a conduction impedance of a second circulation element of a second power-supply phase that is magnetically coupled to the first power-supply phase; and
a third circuit configured to cause the second circuit to lower the conduction impedance of the second circulation element for only a portion of a time during which the first circulation element is closed, the portion of the time being shorter than the time.

7. The power-supply controller of claim 6 wherein the third circuit is configured to cause the second circuit to lower the conduction impedance of the second circulation element by forming a low-impedance path across the second circulation element.

8. The power-supply controller of claim 6 wherein:
the second circuit is configured to open and close a second drive element of the second power-supply phase; and
the third circuit is configured to cause the second circuit to lower the conduction impedance of the second circulation element while the second drive element is open.

9. The power-supply controller of claim 6 wherein:
the second circuit is configured to open and close a second drive element of the second power-supply phase; and
the third circuit is configured to cause the second circuit to deactivate the second circulation element while the second drive element is closed.

10. A power supply, comprising:
a first voltage input node;
a reference node;
an output node configured to provide a regulated output signal;
a first phase coupled to the input, reference, and output nodes;
a second phase coupled to the input, reference, and output nodes and being magnetically coupled to the first phase; and
a power-supply controller, comprising:
a first circuit configured to cause a first current to flow from the input node, through the first phase, to the output node, and
a second circuit configured to cause the second phase of the power supply to operate in a reduced-power-dissipation mode by activating a second circulation switch of the second phase for no more than a portion of a time period during which a second current magnetically induced by the first current flows from the reference node, through the second phase, to the output node, the portion of the time period being smaller than the time period.

11. The power supply of claim 10 wherein:
the first phase comprises:
a first inductor having a first node and having a second node coupled to the output node,
a first drive switch coupled between the input node and the first node of the inductor, and
a first circulation switch coupled between the reference node and the first node of the inductor; and

the second phase comprises:
a second inductor having a first node and having a second node coupled to the output node and being magnetically coupled to the first inductor,
a second drive switch coupled between the input node and the first node of the second inductor, and
the second circulation switch coupled between the reference node and the first node of the second inductor.

12. The power supply of claim 10 wherein the regulated output signal comprises a regulated output voltage.

13. The power supply of claim 10 , further comprising a capacitor coupled between the output node and the reference node.

14. The power supply of claim 10 wherein the reference node comprises a ground node.

15. The power supply of claim 10 wherein the reference node comprises a second voltage input node.

16. A power supply, comprising:
a first voltage input node;
a reference node;
an output node configured to provide a regulated output signal;
a first phase having a first drive switch coupled between the input and output nodes;
a second phase magnetically coupled to the first phase and having a second circulation element coupled between the reference and output nodes; and
a power-supply controller, comprising:
a first circuit configured to open and close the first drive switch,
a second circuit configured to cause a magnetically induced current that flows through the second phase to flow around, and to flow through, the second circulation element, and
a third circuit configured to cause the second circuit to cause the magnetically induced current to flow around the second circulation element for no longer than a fraction of a time during which the first drive switch is closed.

17. The power supply of claim 16 wherein:
the first phase comprises:
a first inductor having a first node coupled to the first drive switch and having a second node coupled to the output node, and
a first circulation switch coupled between the reference node and the first node of the inductor; and

the second phase comprises:
a second inductor having a first node coupled to the second circulation element, having a second node coupled to the output node, and being magnetically coupled to the first inductor, and
a second drive switch coupled between the input node and the first node of the second inductor.

18. The power supply of claim 16 wherein the regulated output signal comprises a regulated output voltage.

19. The power supply of claim 16 , further comprising a capacitor coupled between the output and reference nodes.

20. The power supply of claim 16 wherein the reference node comprises a ground node.

21. The power supply of claim 16 wherein the reference node comprises a second voltage input node.

22. The power supply of claim 16 wherein the second circulation element comprises a diode.

23. The power supply of claim 16 wherein the second circulation element comprises an inherent diode of a second circulation transistor of the second phase.

24. A power supply, comprising:
a first voltage input node;
a reference node;
an output node configured to provide a regulated output signal;
a first phase ha

Assignees

• Wei Jia
• Xing Kun
• Intersil Americas LLC

Inventors

• Wei Jia
• Xing Kun

Classifications

• H02M2001/0064

  Electricity · mapped topic

• Y02B70/1466

  Cross-Sectional Technologies · mapped topic

• H02M3/1588

  comprising at least one synchronous rectifier element (H02M3/1582, H02M3/1584 take precedence) · CPC title

• H02M3/1584 Primary

  with a plurality of power processing stages connected in parallel · CPC title

• H02M1/0064

  Magnetic structures combining different functions, e.g. storage, filtering or transformation · CPC title