Transistor monitor for a multiphase circuit

• US 7,193,410 B2
• Filed: 05/04/2004
• Issued: 03/20/2007
• Est. Priority Date: 05/04/2004
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Guenther, Robert A., Patel, Raoji A.
• Primary Examiner(s): PATEL, PARESH H
• Application Number:
  US10/838,755
• Publication Number:
  US 20050248360A1
• Time in Patent Office: 1,050 Days
• Field of Search: 324/769, 324/158.1, 327/53, 327/538, 327/543, 327/436, 327/437, 361/85, 361/76, 361/101, 361/18
• US Class Current: 324/762.09
• CPC Class Codes: G01R 31/275 for testing individual semiconductor components within integrated circuits
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

A monitor system and method are described for sensing voltage changes in a plurality of transistors of a multiphase circuit comprising a sensor connected to each one of the plurality of transistors for measuring a voltage drop across the each one, a difference detector for comparing the voltage drop to a previous voltage drop attributable to the each one of the plurality of transistors, and a driver circuit for controlling a state of the plurality of transistors, wherein the driver circuit deactivates one or more of the plurality of transistors when the voltage drop varies from the previous voltage drop by a predefined amount.

Claims

1. A monitor for deactivating a single phase section of a multiphase circuit comprising:

a sensor connected to a transistor of said single phase section of said multiphase circuit for measuring a voltage drop across said transistor;

a difference detector for comparing said voltage drop to a previous voltage drop attributable to said transistor; and

a driver circuit for controlling a state of said transistor, wherein said driver circuit deactivates said transistor when said voltage drop varies from said previous voltage drop by a predefined amount.

2. The monitor of claim 1 further comprising:

a memory for storing said measured voltage drop to become said previous voltage drop.

3. The monitor of claim 1 further comprising:

a delay circuit for delaying said comparing by said difference detector to avoid output load transients.

4. The monitor of claim 1 wherein said sensor is implemented using a sample-and-hold circuit.

5. The monitor of claim 1, further comprising:

another sensor connected to another transistor of said single phase section of said multiphase circuit for measuring another voltage drop across said another transistor;

another difference detector for comparing said another voltage drop to another previous voltage drop attributable to said another transistor; and

another driver circuit for controlling another state of said another transistor, wherein said another driver circuit deactivates said another transistor when said another voltage drop varies from said another previous voltage drop by another predefined amount.

6. The monitor of claim 5 wherein said another driver circuit deactivates said another transistor upon deactivation of said transistor, thereby deactivating said single phase section of said multiphase circuit.

7. The monitor of claim 1 further comprising:

a latch circuit for latching said deactivated transistor to a deactivated state.

8. A method for monitoring performance of a plurality of transistors in a multiphase circuit comprising:

measuring a voltage across said plurality of transistors;

comparing said measured voltage against a prior measurement of said voltage; and

deactivating one or more of said plurality of transistors when said measured voltage exceeds said prior measurement by a predetermined amount.

9. The method of claim 8 further comprising:

storing said measured voltages for comparison against new measured voltages.

10. The method of claim 8 further comprising:

delaying said comparing step to allow output load transients to attenuate prior to said comparing.

11. The method of claim 8 further comprising:

deactivating ones of said plurality of transistors that are associated with said deactivated one or more of said plurality of transistors in a phase of said multiphase circuit.

12. The method of claim 8 further comprising:

latching said deactivated one or more transistors in a deactivated state.

13. A system for monitoring a status of a plurality of transistors in a multiphase circuit comprising:

means for evaluating a voltage drop across said plurality of transistors;

means for comparing said measured voltage drop against a previously evaluated voltage drop; and

means for turning off one or more of said plurality of transistors when said measured voltage drop varies from said previously evaluated voltage drop by predefined value.

14. The system of claim 13 further comprising:

means for holding said evaluated voltage drop for comparison against new evaluated voltage drops.

15. The system of claim 13 further comprising:

means for suspending said means for comparing to allow output load transients to attenuate.

16. The system of claim 13 further comprising:

means for turning off ones of said plurality of transistors that are associated with said turned off one or more of said plurality of transistors in a phase of said multiphase circuit.