Switching voltage regulator that adjusts a timing in response to a load transient

• US 6,232,755 B1
• Filed: 01/31/2000
• Issued: 05/15/2001
• Est. Priority Date: 01/31/2000
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Zhang, Michael T.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): PATEL, RAJNIKANT B
• Application Number:
  US09/495,277
• Time in Patent Office: 470 Days
• Field of Search: 323/282, 323/283, 323/284, 323/285, 323/286, 323/222, 323/224, 363/71, 363/80, 363/86, 363/21, 363/16
• US Class Current: 323/282
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

A method includes energizing and de-energizing at least one inductor to furnish an output power. An indication of the output power is monitored to detect when a transient occurs in the output power. The energizing and de-energizing are performed at a predetermined frequency when the transient is not detected; and in response to the detection of the transient, the energizing and de-energizing are performed at a frequency that deviates from the predefined frequency to compensate for the transient.

Claims

1. A switching regulator comprising:

at least one inductor;

at least one switch to energize and de-energize said at least one inductor to furnish an output power; and

a controller to;

monitor an indication of the output power to detect when a transient occurs in the output power,

cause said at least one switch to operate at a predetermined frequency when the controller does not detect the transient, and

in response to the detection of the transient, cause the operation of said at least one switch to deviate from the predetermined frequency to compensate for the transient.

2. The switching regulator of claim 1, wherein

when the controller does not detect the transient said at least one switch operates at the predetermined frequency to energize said at least one inductor during on intervals and de-energize said at least one inductor during off intervals, and

in response to the transient occurs during one of the off intervals, the controller operates said at least one switch to terminate de-energizing of said at least one inductor and begin energizing said at least one inductor.

3. The switching regulator of claim 1, wherein the controller comprises:

an oscillator to generate a periodic signal;

a comparator to compare an indication of an output voltage of the switching regulator to the periodic signal; and

a control circuit coupled to the comparator to control said at least one switch based on the comparison.

4. The switching regulator of claim 3, wherein the control circuit resets the oscillator in response to the detection of the transient.

5. The switching regulator of claim 3, wherein the oscillator comprises a sawtooth oscillator.

6. The switching regulator of claim 5, wherein the control circuit discharges a capacitor of the sawtooth oscillator in response to the detection of the transient.

7. A voltage regulator comprising:

a first switching regulator circuit to transfer first energy that is stored in the first switching regulator circuit to an output terminal of the voltage regulator during first on time intervals and store the first energy during first off time intervals;

a second switching regulator circuit to transfer second energy that is stored in the second switching regulator circuit to the output terminal during second on time intervals and store the second energy during second off time intervals; and

a controller coupled to the first and second switching regulator circuits to;

monitor an indication of an output power of the voltage regulator to detect when a transient occurs in the output power,

interleave the first and second on time intervals in time at least when the controller does not detect the transient,

cause the first and second on time intervals to occur at a predetermined frequency, and

in response to the detection of the transient, cause at least one of the first and second time intervals to occur at a time that deviates from the predetermined frequency to compensate for the transient.

8. The voltage regulator of claim 7, wherein the controller causes one of the first on time intervals and one of the second on time intervals to at least partially overlap in response to the detection of the transient.

9. The voltage regulator of claim 7, wherein the controller comprises:

an oscillator to generate a periodic signal;

a comparator to compare an indication of an output voltage of the switching regulator to the periodic signal; and

a control circuit coupled to the comparator to control the first and second switching regulator circuits based on the comparison.

10. The voltage regulator of claim 9, wherein the control circuit resets the oscillator in response to the detection of the transient.

11. The voltage regulator of claim 10, wherein the oscillator comprises a sawtooth oscillator.

12. The voltage regulator of claim 11, wherein the control circuit discharges a capacitor of the sawtooth oscillator in response to the detection of the transient.

13. A computer system comprising:

a switching regulator to;

monitor an output power of the regulator to detect a transient in the output power,

if the transient is not detected, store energy from an input source in an inductor of the regulator during on time intervals and transfer energy from the inductor to an output terminal of the regulator during off time intervals at a predefined frequency, and

and in response to detection of the transient, cause at least one of the on time intervals to occur at a time that deviates from the predefined frequency to compensate for the transient; and

a processor coupled to the output terminal to receive at least part of the output power.

14. The computer system of claim 13, wherein the regulator comprises:

at least one switch coupled to the inductor to cause the energy to be stored in and the energy to be transferred from the inductor;

an oscillator to generate a periodic signal;

a comparator to compare an indication of an output voltage of the regulator to the periodic signal; and

a control circuit coupled to the comparator to control said at least one switch based on the comparison.

15. The computer system of claim 14, wherein the control circuit resets the oscillator in response to the detection of the transient.

16. The computer system of claim 14, wherein the oscillator comprises a sawtooth oscillator.

17. The computer system of claim 16, wherein the control circuit discharges a capacitor of the sawtooth oscillator in response to the detection of the transient.

18. A method comprising:

energizing and de-energizing at least one inductor to furnish an output power;

monitor an indication of the output power to detect when a transient occurs in the output power;

performing the energizing and de-energizing at a predetermined frequency when the transient is not detected, and

in response to the detection of the transient, performing the energizing and de-energizing at a frequency that deviates from the predetermined frequency to compensate for the transient.

19. The method of claim 18, wherein

when the transient is not detected, the performing the energizing and de-energizing includes energizing said at least one inductor during on intervals and de-energizing said at least one inductor during off intervals, and

in response to the transient, the performing the energizing and de-energizing includes during one of the off intervals, terminating de-energization of said at least one inductor and initiating energization of said at least one inductor.

20. The method of claim 18, further comprising:

using an oscillator to furnish an oscillator signal;

referencing the energization and de-energization to an oscillator signal when the transient is not detected; and

resetting the oscillator in response to the detection of the transient.

21. The method of claim 18, further comprising:

interleaving switching phases of multiple regulators when the transient is not detected; and

aligning the switching phases when the transient is detected.