Method and apparatus for fault condition protection of a switched mode power supply

• US 20040212942A1
• Filed: 05/19/2004
• Published: 10/28/2004
• Est. Priority Date: 03/14/2001
• Status: Active Grant

• Current Assignee: Balu Balakrishnan
• Original Assignee: Balu Balakrishnan
• Inventors: Balakrishnan, Balu
• Granted Patent: US 7,218,495 B2
• Time in Patent Office: Days
• US Class Current: 361/90
• CPC Class Codes: H02H 3/06 with automatic reconnection
• CPC Class Codes: H02H 3/087 for dc applications
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters

Abstract

Methods and apparatuses for fault condition protection of a switched mode power supply. In one aspect of the invention, a power supply circuit having an auto-restart function to turn the power supply on and off repeatedly under fault conditions is included. In one embodiment, one or more off-times following detection of a fault condition is smaller than subsequent off-times.

Claims

1-26. -26. (canceled)

27. A method, comprising:

regulating a delivery of power from a power supply input to a power supply output;

detecting a fault condition in the power supply; and

repeatedly enabling and disabling the power supply during the fault condition, wherein a duration of one or more disable periods follow the detection of the fault condition in the power supply is smaller than a duration of subsequent disable periods.

28. The method of claim 27 wherein detecting the fault condition in the power supply includes detecting an open loop condition in the power supply.

29. The method of claim 28 wherein detecting the open loop condition in the power supply includes detecting at least one of a power supply output short circuit condition and a power supply output overload condition in the power supply.

30. The method of claim 29 wherein the power supply output overload condition is caused by a power supply input under-voltage condition in the power supply.

31. The method of claim 27 wherein regulating the delivery of power from the power supply input to the power supply output includes switching a power switch in response to a switching signal.

32. The method of claim 27 wherein only a duration of a first disable period following the detection of the fault condition in the power supply is smaller than the duration of subsequent disable periods.

33. The power supply circuit of claim 27 wherein the detection of the fault condition in the power supply occurs after the power supply has been in regulation.