Diagnostic and maintenance systems and methods for LED power management integrated circuits

• US 7,606,679 B1
• Filed: 09/25/2006
• Issued: 10/20/2009
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Inventors: Gagea, Leonard, Russell, Anthony, Voicu, Gelu
• Primary Examiner(s): Bui; Bryan
• Application Number:
  US11/535,047
• Time in Patent Office: 1,121 Days
• Field of Search: 702/183, 702/185, 702/187
• US Class Current: 702/183
• CPC Class Codes: H05B 45/52 in a parallel array of LEDs
• CPC Class Codes: H05B 45/54 in a series array of LEDs
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: H05B 45/58 involving end of life detection of LEDs
• CPC Class Codes: H05B 47/24 Circuit arrangements for protecting against overvoltage

Abstract

According to some embodiments, a light emitting diode (LED) power management and diagnostics history recording integrated circuit includes a power management circuit controlling a supply of power to the LED, a diagnostics detection circuit recording a diagnostics history for the LED, a non-volatile diagnostics history memory storing the diagnostics history; and an external interface for transferring externally the diagnostics history stored in the non-volatile diagnostics history memory. The diagnostics history includes diagnostics data for at least two sequential occurrences of a reoccurring fault condition. The diagnostics data may include temperature, under-voltage, over-voltage, open-circuit load, and short-circuit load indicators, among others. A diagnostics analysis system downloads the diagnostics data after a given operation period and performs maintenance decisions according to the diagnostics data. Such systems are particularly useful for diagnosing intermittent faults and/or faults in remotely-located systems, and making maintenance decisions accordingly.

Claims

1. A light-emitting system comprising:

a light-emitting diode load; and

a diagnostics history and power-management integrated circuit connected to the light-emitting diode load, the diagnostics history and power-management integrated circuit comprising;

a power management circuit configured to control a supply of power to the light emitting diode load;

a diagnostics detection circuit connected to the power management circuit and configured to record a set of diagnostics history data for an operation of the light emitting diode load, the set of diagnostics history data including diagnostics data for at least two sequential occurrences of a reoccurring fault condition, the set of diagnostics history data including indicators of a relative order of occurrence of a plurality of occurrences of a plurality of fault conditions;

a non-volatile diagnostics history memory connected to the diagnostics detection circuit and configured to store the set of diagnostics history data; and

an external interface connected to the non-volatile diagnostics history memory and configured to transfer externally the set of diagnostics history data stored in the non-volatile diagnostics history memory.

2. The system of claim 1, wherein:

the reoccurring fault condition is an over-temperature condition for a device selected from the light emitting diode load and the diagnostics history and power management integrated circuit; and

the diagnostics detection circuit includes a temperature detection circuit configured to generate a temperature indicator indicative of a temperature of the device.

3. The system of claim 1, wherein:

the reoccurring fault condition comprises an under-voltage condition for the light emitting diode load; and

the diagnostics detection circuit includes an under-voltage detection circuit configured to generate an under-voltage indicator indicative of the under-voltage condition.

4. The system of claim 1, wherein:

the reoccurring fault condition comprises an over-voltage condition for the light emitting diode load; and

the diagnostics detection circuit includes an over-voltage detection circuit configured to generate an over-voltage indicator indicative of the over-voltage condition.

5. The system of claim 1, wherein:

the reoccurring fault condition comprises an open circuit condition for the light emitting diode load; and

the diagnostics detection circuit includes an open circuit detection circuit configured to generate an open circuit indicator indicative of the open circuit condition.

6. The system of claim 1, wherein:

the reoccurring fault condition comprises a short-circuit condition for the light emitting diode load; and

the diagnostics detection circuit includes a short-circuit detection circuit configured to generate a short-circuit indicator indicative of the short-circuit condition.

7. The system of claim 1, wherein the set of diagnostics history data includes a plurality of fault type occurrence counts each indicative of a number of detected occurrences of a corresponding fault type.

8. The system of claim 7, wherein the plurality of fault type occurrence counts includes an over-temperature count, an under-voltage count, an over-voltage count, an open circuit count, and a short circuit count.

9. A diagnostics history and power management integrated circuit comprising:

a power management circuit configured to control a supply of power to a light emitting diode load;

a diagnostics detection circuit connected to the power management circuit and configured to record a set of diagnostics history data for an operation of the light emitting diode load, the set of diagnostics history data including diagnostics data for at least two sequential occurrences of a reoccurring fault condition, the set of diagnostics history data including indicators of a relative order of occurrence of a plurality of occurrences of a plurality of fault conditions;

a non-volatile diagnostics history memory connected to the diagnostics detection circuit and configured to store the set of diagnostics history data; and

an external interface connected to the non-volatile diagnostics history memory and configured to transfer externally the set of diagnostics history data stored in the non-volatile diagnostics history memory.

10. A diagnostics history recording and retrieval system comprising:

a light emitting diode diagnostics history and power-management integrated circuit comprising;

a power management circuit configured to control a supply of power to a light emitting diode load;

a diagnostics detection circuit connected to the power management circuit and configured to record a set of diagnostics history data for an operation of the light emitting diode load, the set of diagnostics history data including diagnostics data for at least two sequential occurrences of a reoccurring fault condition, the set of diagnostics history data including indicators of a relative order of occurrence of a plurality of occurrences of a plurality of fault conditions;

a non-volatile diagnostics history memory connected to the diagnostics detection circuit and configured to store the set of diagnostics history data; and

an external interface connected to the non-volatile diagnostics history memory and configured to transfer externally the set of diagnostics history data stored in the non-volatile diagnostics history memory; and

a diagnostics history analysis system connected to the external interface and configured to receive the set of diagnostics history data through the external interface.

11. The system of claim 10, wherein the diagnostics history analysis system is configured to generate a maintenance determination for the light emitting diode according to the set of diagnostics history data.

12. The system of claim 10, wherein the diagnostics history analysis system is connected to the external interface over a wide area network.

13. A light emitting diode diagnostics and power management method comprising:

employing a diagnostics history and power-management integrated circuit connected to a light-emitting diode load to

control a supply of power to the light emitting diode load;

record a set of diagnostics history data for an operation of the light emitting diode load, the set of diagnostics history data including diagnostics data for at least two sequential occurrences of a reoccurring fault condition, the set of diagnostics history data including indicators of a relative order of occurrence of a plurality of occurrences of a plurality of fault conditions;

store the set of diagnostics history data in a non-volatile diagnostics history memory of the diagnostics history and power management integrated circuit; and

transferring the set of diagnostics history data stored in the non-volatile diagnostics history memory to a diagnostics history analysis system external to the diagnostics history and power management integrated circuit.

14. The method of claim 13, wherein the set of diagnostics history data includes a set of temperature history data for the light emitting diode load.

15. The method of claim 13, wherein the set of diagnostics history data includes a set of under-voltage history data for the light emitting diode load.

16. The method of claim 13, wherein the set of diagnostics history data includes a set of over-voltage history data for the light emitting diode load.

17. The method of claim 13, wherein the set of diagnostics history data includes a set of open circuit history data for the light emitting diode load.

18. The method of claim 13, wherein the set of diagnostics history data includes a set of short-circuit history data for the light emitting diode load.

19. A system comprising:

a light-emitting diode load; and

a diagnostics history and power-management integrated circuit connected to the light-emitting diode load, the diagnostics history and power-management integrated circuit comprising;

means for controlling a supply of power to the light emitting diode load;

means for recording a set of diagnostics history data for an operation of the light emitting diode load, the set of diagnostics history data including diagnostics data for at least two sequential occurrences of a reoccurring fault condition, the set of diagnostics history data including indicators of a relative order of occurrence of a plurality of occurrences of a plurality of fault conditions;

a non-volatile diagnostics history memory configured to store the set of diagnostics history data; and

means for transferring externally the set of diagnostics history data stored in the non-volatile diagnostics history memory.