Adaptive thresholding technique for power supplies during margining events

• US 7,568,117 B1
• Filed: 02/16/2006
• Issued: 07/28/2009
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• Current Assignee: Intersil Americas LLC (Renesas Electronics Corporation)
• Original Assignee: Zilker Labs LLC (Renesas Electronics Corporation)
• Inventors: Fernald, Kenneth W.
• Primary Examiner(s): SURYAWANSHI, SURESH
• Application Number:
  US11/355,447
• Time in Patent Office: 1,258 Days
• Field of Search: 713/300, 713/340
• US Class Current: 713/340
• CPC Class Codes: H02M 1/008 Plural converter units for generating at two or more independent and non-parallel outputs, e.g. systems with plural point of load switching regulators
• CPC Class Codes: H02M 1/38 Means for preventing simultaneous conduction of switches
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

Adaptive thresholding technique for power supplies during margining events. A power supply may include a fault detection mechanism for monitoring an output voltage of the power supply to determine whether the output voltage is greater than a first over-voltage threshold or less than a first under-voltage threshold. If a margining event changes the power supply output voltage, the fault detection mechanism may dynamically change a first over-voltage threshold and a first under-voltage threshold based on the margining event to a second over-voltage threshold and a second under-voltage threshold. Then, during the margining event, the fault detection mechanism may monitor the output voltage of the power supply to determine whether the output voltage is greater than a second over-voltage threshold or less than a second under-voltage threshold. The fault detection mechanism may dynamically change a fault threshold in proportion to the change in the power supply output voltage.

Claims

1. A method for controlling a power supply, the method comprising:

monitoring an output voltage of the power supply to determine whether the output voltage is greater than a first over-voltage threshold or less than a first under-voltage threshold; and

in response to a margining event changing the output voltage of the power supply, performing at least one of;

     1) monitoring the output voltage of the power supply to determine whether the output voltage is greater than a second over-voltage threshold, and

     2) monitoring the output voltage of the power supply to determine whether the output voltage is less than a second under-voltage threshold.

2. The method of claim 1, wherein voltage values corresponding to the second over-voltage threshold and the second under-voltage threshold are dependent upon the margining event.

3. The method of claim 1, further comprising, in response to a margining event increasing the output voltage of the power supply, dynamically increasing a voltage value corresponding to the first over-voltage threshold in proportion to the increase in the power supply output voltage to a voltage value corresponding to the second over-voltage threshold, and maintaining a voltage value corresponding to the first under-voltage threshold.

4. The method of claim 3, wherein, in response to a margining event increasing the output voltage of the power supply, monitoring the output voltage of the power supply to determine whether the output voltage is greater than the second over-voltage threshold, and monitoring the output voltage of the power supply to determine whether the output voltage is less than the first under-voltage threshold.

5. The method of claim 1, further comprising, in response to a margining event decreasing the output voltage of the power supply, dynamically decreasing a voltage value corresponding to the first under-voltage threshold in proportion to the decrease in the power supply output voltage to a voltage value corresponding to the second under-voltage threshold, and maintaining a voltage value corresponding to the first over-voltage threshold.

6. The method of claim 5, wherein, in response to a margining event decreasing the output voltage of the power supply, monitoring the output voltage of the power supply to determine whether the output voltage is greater than the first over-voltage threshold, and monitoring the output voltage of the power supply to determine whether the output voltage is less than the second under-voltage threshold.

7. The method of claim 1, further comprising, in response to a margining event changing the output voltage of the power supply, monitoring the output voltage of the power supply to determine whether the output voltage is greater than a second over-voltage threshold, and monitoring the output voltage of the power supply to determine whether the output voltage is less than a second under-voltage threshold.

8. The method of claim 1, further comprising, in response to a margining event increasing the output voltage of the power supply, dynamically increasing a voltage value corresponding to the first over-voltage threshold in proportion to the increase in the power supply output voltage to a voltage value corresponding to the second over-voltage threshold, and dynamically increasing a voltage value corresponding to the first under-voltage threshold in proportion to the increase in the power supply output voltage to a voltage value corresponding to the second under-voltage threshold.

9. The method of claim 1, further comprising, in response to a margining event decreasing the output voltage of the power supply, dynamically decreasing a voltage value corresponding to the first over-voltage threshold in proportion to the decrease in the power supply output voltage to a voltage value corresponding to the second over-voltage threshold, and dynamically decreasing a voltage value corresponding to the first under-voltage threshold in proportion to the decrease in the power supply output voltage to a voltage value corresponding to the second under-voltage threshold.

10. The method of claim 1, further comprising, in response to a margining event changing the output voltage of the power supply, dynamically calculating the difference between the changed power supply output voltage and a target output voltage, and dynamically changing the first over-voltage threshold and the first under-voltage threshold by the calculated difference.

11. The method of claim 1, wherein, during a margining event, if the power supply output voltage is greater than the second over-voltage threshold or less than the second under-voltage threshold, indicating a fault and initiating a fault recovery procedure.

12. A power supply comprising:

a memory operable to store a first over-voltage threshold and a first under-voltage threshold; and

a fault detection mechanism configured to monitor an output voltage of the power supply to determine whether the output voltage is greater than the first over-voltage threshold or less than the first under-voltage threshold;

wherein, in response to a margining event changing the output voltage of the power supply, the fault detection mechanism is further configured to perform at least one of;

     1) monitoring the output voltage of the power supply to determine whether the output voltage is greater than a second over-voltage threshold, and

     2) monitoring the output voltage of the power supply to determine whether the output voltage is less than a second under-voltage threshold.

13. The power supply of claim 12, wherein voltage values corresponding to the second over-voltage threshold and the second under-voltage threshold are dependent upon the margining event.

14. The power supply of claim 12, wherein, in response to a margining event increasing the output voltage of the power supply, the fault detection mechanism is configured to dynamically increase a voltage value corresponding to the first over-voltage threshold in proportion to the increase in the power supply output voltage to a voltage value corresponding to the second over-voltage threshold, and maintain a voltage value corresponding to the first under-voltage threshold.

15. The power supply of claim 14, wherein, in response to a margining event increasing the output voltage of the power supply, the fault detection mechanism is configured to monitor the output voltage of the power supply to determine whether the output voltage is greater than the second over-voltage threshold, and monitor the output voltage of the power supply to determine whether the output voltage is less than the first under-voltage threshold.

16. The power supply of claim 12, wherein, in response to a margining event decreasing the output voltage of the power supply, the fault detection mechanism is configured to dynamically decrease a voltage value corresponding to the first under-voltage threshold in proportion to the decrease in the power supply output voltage to a voltage value corresponding to the second under-voltage threshold, and maintain a voltage value corresponding to the first over-voltage threshold.

17. The power supply of claim 16, wherein, in response to a margining event decreasing the output voltage of the power supply, the fault detection mechanism is configured to monitor the output voltage of the power supply to determine whether the output voltage is greater than the first over-voltage threshold, and monitor the output voltage of the power supply to determine whether the output voltage is less than the second under-voltage threshold.

18. The power supply of claim 12, wherein, in response to a margining event changing the output voltage of the power supply, the fault detection mechanism is configured to monitor the output voltage of the power supply to determine whether the output voltage is greater than a second over-voltage threshold, and monitor the output voltage of the power supply to determine whether the output voltage is less than a second under-voltage threshold.

19. The power supply of claim 12, wherein, in response to a margining event increasing the output voltage of the power supply, the fault detection mechanism is configured to dynamically increase a voltage value corresponding to the first over-voltage threshold in proportion to the increase in the power supply output voltage to a voltage value corresponding to the second over-voltage threshold, and dynamically increase a voltage value corresponding to the first under-voltage threshold in proportion to the increase in the power supply output voltage to a voltage value corresponding to the second under-voltage threshold.

20. The power supply of claim 12, wherein, in response to a margining event decreasing the output voltage of the power supply, the fault detection mechanism is configured to dynamically decrease a voltage value corresponding to the first over-voltage threshold in proportion to the decrease in the power supply output voltage to a voltage value corresponding to the second over-voltage threshold, and dynamically decrease a voltage value corresponding to the first under-voltage threshold in proportion to the decrease in the power supply output voltage to a voltage value corresponding to the second under-voltage threshold.

21. The power supply of claim 12, wherein, in response to a margining event changing the output voltage of the power supply, the fault detection mechanism is configured to dynamically calculate the difference between the changed power supply output voltage and a target output voltage, and the fault detection mechanism is further configured to dynamically change the first over-voltage threshold and the first under-voltage threshold by the calculated difference.

22. The power supply of claim 12, wherein, during a margining event, if the power supply output voltage is greater than the second over-voltage threshold or less than the second under-voltage threshold, the fault detection mechanism is configured to indicate a fault and initiate a fault recovery procedure.

23. A power distribution system including a plurality of power supplies, wherein each power supply comprises:

a memory operable to store a first over-voltage threshold and a first under-voltage threshold; and

a fault detection mechanism configured to monitor an output voltage of the power supply to determine whether the output voltage is greater than the first over-voltage threshold or less than the first under-voltage threshold;

wherein, in response to a margining event changing the output voltage of the power supply, the fault detection mechanism is further configured to monitor the output voltage of the power supply to determine whether the output voltage is greater than a second over-voltage threshold, and monitor the output voltage of the power supply to determine whether the output voltage is less than a second under-voltage threshold.