Variable switching frequency voltage regulator to optimize power loss

• US 6,639,391 B2
• Filed: 02/25/2002
• Issued: 10/28/2003
• Est. Priority Date: 02/25/2002
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Huang, Lilly, Kumar, Pavan M.
• Primary Examiner(s): Berhane, Adolf D.
• Assistant Examiner(s): Laxton, Gary L.
• Application Number:
  US10/082,654
• Publication Number:
  US 20030160597A1
• Time in Patent Office: 610 Days
• Field of Search: 323/265, 323/271, 323/282, 323/351, 323/284, 323/224, 323/225
• US Class Current: 323/284
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: H02M 1/0019 the disturbance parameters being load current fluctuations
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

According to one embodiment, a computer system is disclosed. The computer system includes a central processing unit (CPU) and a voltage regulator coupled to the CPU. The voltage regulator operates at a variable switching frequencies based upon the status of a feedback signal which indicates load transient events.

Claims

1. A computer system comprising:

a central processing unit (CPU); and

a voltage regulator, coupled to the CPU, that operates at a first switching frequency whenever a feedback signal is deactivated, and operates at a second switching frequency whenever the feedback signal is activated.

2. The computer system of claim 1 wherein the feedback signal is activated whenever the CPU transient is greater than a predetermined threshold and is deactivated whenever the CPU transient is less than the predetermined threshold.

3. The computer system of claim 1 wherein the voltage regulator comprises control circuitry coupled to the CPU that receives the feedback signal.

4. The computer system of claim 3 wherein the feedback signal is received at the control circuitry from the CPU.

5. The computer system of claim 3 wherein the voltage regulator further comprises:

an input filter;

a power stage coupled to the input filter and the control circuitry; and

an output filter coupled to the power stage and the CPU.

6. The computer system of claim 5 further comprising a transient detect module, coupled to the CPU and the control circuitry, that monitors the CPU transient and generates the feedback signal.

7. The computer system of claim 5 further comprising a power supply coupled to the input filter.

8. A voltage regulator comprising:

a power stage; and

control circuitry, coupled to the power stage, to operate the voltage regulator at a variable switching frequency based upon the status of a received feedback signal, wherein the feedback signal is activated whenever a load transient is greater than a predetermined threshold and is deactivated whenever the load transient is less than the predetermined threshold.

9. The voltage regulator of claim 8 further comprising:

an input filter coupled to the power stage; and

an output filter coupled to the power stage and a load.

10. The voltage regulator of claim 9 wherein the feedback signal is received at the control circuitry from the load.

11. The voltage regulator of claim 9 further comprising a transient detect module, coupled to the load and the control circuitry, that monitors the load transient and generates the feedback signal.

12. A system comprising:

a load; and

a voltage regulator, coupled to the load, to operate at a first switching frequency whenever a feedback signal activated, and at a second switching frequency whenever the feedback signal is deactivated.

13. The system of claim 12 wherein the feedback signal is activated whenever the load transient is greater than a predetermined threshold and is deactivated whenever the load transient is less than the predetermined threshold.

14. The system of claim 12 wherein the voltage regulator comprises control circuitry coupled to the load that receives the feedback signal.

15. The system of claim 14 wherein the feedback signal is received at the control circuitry from the load.

16. The system of claim 14 wherein the voltage regulator further comprises:

an input filter;

a power stage coupled to the input filter and the control circuitry; and

an output filter coupled to the power stage and the load.

17. The system of claim 16 further comprising a transient detect module, coupled to the load and the control circuitry, that monitors the load transient and generates the feedback signal.

18. The system of claim 16 further comprising a power supply coupled to the input filter.

19. A method comprising:

operating a voltage regulator at a first switching frequency;

receiving a first feedback signal from a load indicating that a load transient is greater than a predetermined threshold; and

operating the voltage regulator at a second switching frequency in response to receiving the first feedback signal.

20. The method of claim 19 further comprising:

receiving a second feedback signal from a load indicating that the load transient has fallen below the predetermined threshold; and

operating the voltage regulator at a first switching frequency in response to receiving the second feedback signal.