Switching pulse-width modulated voltage regulator and method of controlling a switching pulse-width modulated voltage regulator

• US 8,963,519 B2
• Filed: 07/09/2012
• Issued: 02/24/2015
• Est. Priority Date: 09/05/2011
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Zambetti, Osvaldo Enrico, Giorgetti, Daniele
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Quddus, Nusrat
• Application Number:
  US13/544,780
• Publication Number:
  US 20130057240A1
• Time in Patent Office: 960 Days
• Field of Search: 323/222, 323/235, 323/237, 323365-268, 323/272, 323/279, 323282-290, 323/901, 363/53, 363/65, 363/86, 363/87, 363/89, 363/81, 363/125, 363/127, 363/56
• US Class Current: 323/271
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel

Abstract

A switching voltage regulator includes a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal based on a difference between the reference voltage and the feedback voltage, and a control module configured to generate a gain control threshold signal based on at least one of the reference voltage and the feedback voltage. The control module may be configured to control a duration of a PWM pulse based on the at least one of the reference voltage and the feedback voltage. The feedback voltage may a regulated output voltage of the switching voltage regulator. The switching voltage regulator may be implemented in an analog or a digital manner.

Claims

1. A switching voltage regulator, comprising:

a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal based on a difference between the reference voltage and the feedback voltage;

at least one pulse-width modulated (PWM) power stage; and

a control module configured to;

generate a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

control a switching frequency of the at least one PWM power stage based at least in part on the comparison signal and on the gain control threshold signal, wherein a change in the switching frequency in response to a transient in a regulated output voltage is proportional to the comparison signal.

2. The switching voltage regulator of claim 1 wherein the control module is configured to control a duration of a PWM pulse based on the at least one of the reference voltage and the feedback voltage.

3. The switching voltage regulator of claim 1 wherein the feedback voltage is a regulated output voltage of the switching voltage regulator.

4. The switching voltage regulator of claim 1 wherein the comparison signal is a comparison voltage and the comparison module comprises an error amplifier configured to receive the reference voltage and the feedback voltage and to generate the comparison voltage.

5. The switching voltage regulator of claim 4 wherein the control module comprises:

a voltage controlled oscillator configured to generate a train of pulses at a frequency determined by said comparison voltage and having a gain based on the gain control threshold signal.

6. The switching voltage regulator of claim 5 wherein the control module further comprises a generator of PWM pulses configured to drive the at least one PWM power stage and a duration of the PWM pulses generated is based on the at least one of the reference voltage and the feedback voltage.

7. The switching voltage regulator of claim 6, comprising a feedback impedance coupled between an output terminal of the regulator and a feedback terminal of the error amplifier, and an integrating impedance coupled between the feedback terminal and an output terminal of the error amplifier.

8. A switching voltage regulator, comprising:

a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal based on a difference between the reference voltage and the feedback voltage;

at least one pulse-width modulated (PWM) power stage; and

a control module configured to;

generate a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

control a switching frequency of the at least one PWM power stage based at least in part on the comparison signal and on the gain control threshold signal, wherein the control module includes a voltage controlled oscillator configured to generate a train of pulses at a frequency determined by said comparison voltage and having a gain based on the gain control threshold signal and a start-up block configured to receive the at least one of the reference voltage and the feedback voltage and to provide the gain control threshold signal to the voltage controlled oscillator, the gain control threshold signal being a largest of a minimum triggering threshold signal and the at least one of the reference voltage and the feedback voltage.

9. A switching voltage regulator, comprising:

a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal based on a difference between the reference voltage and the feedback voltage;

at least one pulse-width modulated (PWM) power stage; and

a control module configured to;

generate a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

control a switching frequency of the at least one PWM power stage based at least in part on the comparison signal and on the gain control threshold signal, wherein,

the at least one PWM power stage comprises a plurality of PWM power stages;

the feedback voltage is a regulated output voltage of the switching voltage regulator;

the comparison signal is a comparison voltage and the comparison module includes an error amplifier configured to receive the reference voltage and the feedback voltage and to generate the comparison voltage; and

the control module includes;

a voltage controlled oscillator configured to generate a train of pulses at a frequency determined by said comparison voltage and having a gain based on the gain control threshold signal;

a plurality of PWM pulse generators configured to generate PWM pulses to drive respective PWM power stages of the plurality of PWM power stages wherein a duration of the PWM pulses is based on the at least one of the reference voltage and the feedback voltage;

a start-up block configured to receive the at least one of the reference voltage and the feedback voltage and to provide the gain control threshold signal to the voltage controlled oscillator, the gain control threshold signal being a largest of a minimum triggering threshold signal and the at least one of the reference voltage and the feedback voltage; and

a state machine configured to receive the train of pulses generated by said voltage controlled oscillator and to generate for each of said PWM pulse generators a respective train of pulses obtained by frequency division of said train of pulses generated by the voltage controlled oscillator.

10. A switching voltage regulator, comprising:

a comparison module configured to receive a reference voltage and a feedback voltage and to generate a comparison signal based on a difference between the reference voltage and the feedback voltage;

at least one pulse-width modulated (PWM) power stage; and

a control module configured to;

generate a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

control the at least one PWM power stage based at least in part on the comparison signal and on the gain control threshold signal, wherein,

the at least one PWM power stage comprises a plurality of PWM power stages each having a PWM pulse generator;

the comparison module comprises;

a first analog-to-digital converter configured to receive the reference voltage and the feedback voltage; and

a first proportional-integral-derivative (PID) controller configured to receive an output of the first analog-to-digital converter and to generate the comparison signal; and

the control module comprises;

an accumulator configured to generate a train of pulses at a frequency based on the comparison signal, wherein the gain control threshold signal is a tripping threshold of the accumulator; and

an interleaving oscillator configured to generate a plurality of pulse trains based on the train of pulses generated by the accumulator.

11. The switching voltage regulator of claim 10 wherein the PWM pulse generators are configured to generate PWM pulses having a duration based on the at least one of the reference voltage and the feedback voltage.

12. The switching voltage regulator of claim 10 wherein gain control reference signal is proportional to the at least one of the reference voltage and the feedback voltage.

13. The switching voltage regulator of claim 12 wherein the control module comprises a parameter generator configured to receive the reference voltage and to output the gain control threshold signal.

14. The switching voltage regulator of claim 13 wherein the parameter generator is configured to output a pulse duration control signal based on the reference voltage signal.

15. The switching voltage regulator of claim 12 wherein the control module comprises:

a second analog-to-digital converter configured to receive the feedback voltage and to generate a control signal based on the feedback voltage; and

a parameter generator configured to receive the control signal generated by the second analog-to-digital converter and to output the gain control threshold signal.

16. The switching voltage regulator of claim 15 wherein the parameter generator is configured to output a pulse duration control signal based on the control signal generated by the second analog-to-digital converter.

17. The switching voltage regulator of claim 10 wherein the gain control threshold signal is a largest of a minimum triggering threshold signal and the at least one of the reference voltage and the feedback voltage.

18. A method, comprising:

generating a regulated voltage which tracks a reference voltage using a constant-on-time switching voltage regulator, by;

generating a comparison signal based on the reference voltage and a feedback voltage;

generating a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

controlling the voltage regulator based at least in part on the comparison signal and on the gain control threshold signal, the controlling including controlling a switching frequency of the voltage regulator, wherein a change in the switching frequency in response to a transient in the regulated output voltage is proportional to the comparison signal.

19. The method of claim 18 wherein the controlling the voltage regulator comprises:

controlling a duration of pulse width modulated (PWM) pulses based on the at least one of the reference voltage and the feedback voltage.

20. The method of claim 18 wherein the feedback voltage is the regulated output voltage of the switching voltage regulator.

21. The method of claim 18, comprising:

generating a train of pulses at a frequency based on the comparison signal using a voltage controlled oscillator having a gain based on the gain control threshold signal; and

generating a plurality of PWM pulses to drive respective PWM power stages of the switching voltage regulator, wherein a duration of the PWM pulses is based on the at least one of the reference voltage and the feedback voltage.

22. A method, comprising:

generating a regulated voltage which tracks a reference voltage using a constant-on-time switching voltage regulator, by;

generating a comparison signal based on the reference voltage and a feedback voltage;

generating a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

controlling the voltage regulator based at least in part on the comparison signal and on the gain control threshold signal, wherein the generating the gain control threshold signal comprises selecting a largest of a minimum triggering threshold signal and the at least one of the reference voltage and the feedback voltage.

23. A method, comprising:

generating a regulated voltage which tracks a reference voltage using a constant-on-time switching voltage regulator, by;

generating a comparison signal based on the reference voltage and a feedback voltage;

generating a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

controlling the voltage regulator based at least in part on the comparison signal and on the gain control threshold signal, the controlling including controlling a switching frequency of the voltage regulator, wherein the voltage regulator comprises,

a first analog-to-digital converter configured to receive the reference voltage and the feedback voltage;

a first proportional-integral-derivative (PID) controller configured to receive an output of the first analog-to-digital converter and to generate the comparison signal; and

an accumulator configured to generate a train of pulses at a frequency based on the comparison signal, wherein the generating the gain control threshold signal comprises generating a tripping threshold of the accumulator.

24. A system, comprising:

a processor; and

a switching voltage regulator configured to provide power to the processor and including;

means for generating a comparison signal based on a reference voltage and a feedback voltage;

means for generating a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

means for controlling a switching frequency of the switching voltage regulator based on the comparison signal and the gain control threshold signal, wherein a change in the switching frequency in response to a transient in a regulated output voltage of the switching voltage regulator is proportional to the comparison signal.

25. The system of claim 24 wherein the switching voltage regulator comprises means for generating a pulse width modulated (PWM) pulse duration control signal based on the at least one of the reference voltage and the feedback voltage.

26. The system of claim 24 wherein the feedback voltage is the regulated output voltage of the switching voltage regulator.

27. The system of claim 26 wherein,

the switching voltage regulator comprises a plurality of PWM power stages and a voltage controlled oscillator having a gain based on the gain control threshold signal;

and

the comparison signal is a comparison voltage and the means for generating the comparison signal includes an error amplifier configured to receive the reference voltage and the feedback voltage and to generate the comparison voltage.

28. The system of claim 24 wherein the means for generating the gain control threshold signal is configured to receive the at least one of the reference voltage and the feedback voltage and to provide the gain control threshold signal to a voltage controlled oscillator, the gain control threshold signal being a largest of a minimum triggering threshold signal and the at least one of the reference voltage and the feedback voltage.

29. A system, comprising:

a processor; and

a switching voltage regulator configured to provide power to the processor and including;

means for generating a comparison signal based on a reference voltage and a feedback voltage;

means for generating a gain control threshold signal based on at least one of the reference voltage and the feedback voltage; and

means for controlling a switching frequency of the switching voltage regulator based on the comparison signal and the gain control threshold signal, wherein the switching voltage regulator comprises;

a plurality of PWM power stages each having a PWM pulse generator;

a first analog-to-digital converter configured to receive the reference voltage and the feedback voltage;

a first proportional-integral-derivative (PID) controller configured to receive an output of the first analog-to-digital converter and to generate the comparison signal;

an accumulator configured to generate a train of pulses at a frequency based on the comparison signal, wherein the gain control threshold signal is a tripping threshold of the accumulator; and

an interleaving oscillator configured to generate a plurality of pulse trains based on the train of pulses generated by the accumulator.