Dynamic hysteresis voltage regulation

• US 6,188,206 B1
• Filed: 12/08/1999
• Issued: 02/13/2001
• Est. Priority Date: 12/08/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Nguyen, Don J., Solivan, Thovane
• Primary Examiner(s): Sterrett, Jeffrey
• Application Number:
  US09/457,488
• Time in Patent Office: 433 Days
• Field of Search: 323/222, 323/282, 323/283, 323/284, 363/84, 363/89
• US Class Current: 323/222
• CPC Class Codes: H02M 3/1563 without using an external clock H02M3/158 takes precedence
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A dynamic switching voltage regulator includes a load indicator, power switches, and a controller. The load indicator generates a load signal responsive to different output load conditions of the regulator. The controller receives the load signal and drives the power switches at a first switching frequency. The controller changes the switching frequency to a second frequency in response to a change in the load signal.

Claims

1. A dynamic switching voltage regulator, comprising:

a load indicator to generate a load signal responsive to different output load conditions of said regulator, where said load signal indicates level of an output voltage;

at least one switch; and

a controller configured to receive said load signal, said controller driving said at least one switch at a first switching frequency by adjusting hysteretic level of the output voltage when the output voltage reaches a first level, said controller changing the switching frequency to a second frequency by appropriately adjusting the hysteretic level of the output voltage when the output voltage reaches a second level, such that the change in the switching frequency optimizes quiescent power dissipation of the voltage regulator.

2. The regulator of claim 1, further comprising;

a drive circuit disposed between said controller and said at least one switch, said drive circuit operating to supply sufficient power to drive said at least one switch at the switching frequency.

3. The regulator of claim 1, further comprising:

an output filter coupled to said at least one switch, said output filter supplying a regulated DC voltage to an output load.

4. The regulator of claim 3, wherein said output filter supplies the regulated DC voltage by charging and discharging energy supplied by said at least one switch.

5. The regulator of claim 4, wherein said output filter includes an inductor and a capacitor, said controller charging the inductor with a transferred energy from said at least one switch and discharging that energy through the capacitor.

6. The regulator of claim 5, wherein said output filter further includes a feedback resistor, said feedback resistor operating to inform said controller about an output load current.

7. The regulator of claim 6, wherein the controller changes the switching frequency of said at least one switch by adjusting an output ripple voltage level.

8. The regulator of claim 7, wherein the controller sets the output ripple voltage level in proportion to the output load current.

9. The regulator of claim 1, wherein the controller changes the switching frequency of said at least one switch by adjusting an output ripple voltage level.

10. The regulator of claim 9, wherein the controller increases the switching frequency by decreasing the output ripple voltage level in response to the change in said load signal from a heavy to light load.

11. A variable ripple-mode switching regulator, comprising:

a plurality of switches;

a load indication circuit generating a load signal indicating an output load condition of the regulator; and

a controller configured to adjust an operating switching frequency by varying an output ripple voltage level, said controller dynamically varying said ripple voltage level according to said load signal.

12. The regulator of claim 11, wherein the controller increases the switching frequency by decreasing the output ripple voltage level in response to a change in said load signal from a heavy to light load.

13. A method for controlling an operating switching frequency of switches in a voltage regulator, comprising:

receiving an output load indication signal; and

adjusting said operating switching frequency in response to a change in said output load indication signal, where said operating switching frequency is adjusted by appropriately varying the hysteresis level of an output voltage.

14. The method of claim 13, wherein said adjusting said operating switching frequency includes driving the operating switching frequency at a first frequency by accordingly adjusting hysteresis level of an output voltage, if the load signal indicates a heavy output load, or driving the operating switching frequency at a second frequency higher than the first frequency, if the load signal indicates a light output load.

15. The method of claim 14, further comprising:

monitoring an output load current; and

adjusting the hysteresis level in proportion to said output load current.

16. A computer program, residing on a computer readable medium, the program comprising executable instructions that enable the computer to:

receive an output load indication signal; and

adjust said operating switching frequency in response to a change in said output load indication signal, where said operating switching frequency is adjusted by appropriately varying the hysteresis level of an output voltage.

17. A computer system, comprising:

an AC-to-DC converter receiving AC power, said converter converting AC power to DC power, and generating a DC voltage;

a processor operating to generate an output load indication signal; and

a dynamic ripple-mode voltage regulator having an operating switching frequency, said regulator configured to receive the DC voltage generated by said AC-to-DC converter, said regulator outputting a regulated DC voltage by dynamically changing said switching frequency, said switching frequency dynamically changed by appropriately adjusting a ripple level of an output voltage in response to an output load indication signal.

18. The computer system of claim 17, wherein said voltage regulator increases the operating switching frequency by decreasing the output ripple voltage level in response to a change in said load indication signal from heavy to light load.

19. The computer system of claim 17, further comprising:

a memory; and

input/output devices coupled to said voltage regulator, said input/output devices, processor and memory configured to receive the regulated DC voltage, and collectively provide an output load to said voltage regulator.