Predictive digital current controllers for switching power converters

• US 7,148,669 B2
• Filed: 02/02/2004
• Issued: 12/12/2006
• Est. Priority Date: 02/02/2004
• Status: Active Grant

• Current Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Chen, Jingquan, Erickson, Robert W., Maksimovic, Dragan, Prodic, Aleksandar
• Primary Examiner(s): Sterrett, Jeffrey
• Application Number:
  US10/770,018
• Publication Number:
  US 20050168198A1
• Time in Patent Office: 1,044 Days
• Field of Search: 323/222, 323/282, 323/283
• US Class Current: 323/283
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• CPC Class Codes: H02M 3/157 with digital control
• 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

The present invention provides a method for producing a controlled output voltage for a switching power converter under current control using pulse width modulation, the switching power converter including a predictive digital current-mode controller and a digital pulse width modulator. The current control results in an unstable output voltage, and the pulse width modulation method is selected to eliminate the instability of the output voltage.

Claims

1. A method for producing a stable output voltage for a switching power converter under predictive digital current control and using pulse width modulation, said method comprising:

selecting one of peak current control and average current control as said predictive digital current control;

selecting one of leading edge pulse width modulation or triangular pulse width modulation as said pulse width modulation; and

controlling said switching power converter according to said selected current control and said selected pulse width modulation to produce said stable output voltage.

2. The method of claim 1 wherein said current control is a peak current control.

3. The method of claim 2 wherein said pulse width modulation method is a leading-edge pulse width modulation.

4. The method of claim 1 wherein said current control is an average current control.

5. The method of claim 4 wherein said pulse width modulation method is a triangular pulse width modulation.

6. The method of claim 1 wherein:

said predictive current control comprises;

sampling an input reference current at the beginning of each next switching cycle; and

predicting a next duty cycle of a pulsating control signal to generate a next duty cycle control signal; and

said pulse width modulation comprises applying said next diary cycle control signal to a pulse width modulation signal corresponding to said selected pulse width modulation method to generate said pulsating control signal to produce said controlled output voltage for said switching power converter.

7. The method of claim 6 wherein said pulse width modulation is analog pulse width modulation, the method further comprising converting said next duty cycle control signal to an analog control signal for use by said analog pulse width modulator.

8. A method for producing a continued output voltage for a switching power converter under predictive digital current control and using pulse width modulation, said method comprising:

selecting one of a peak current control and an average current control as said predictive digital current control that results in an unstable output voltage;

selecting one of a leading-edge pulse width modulation and a triangular pulse width modulation as said pulse width modulation; and

controlling said switching power converter according to said selected current control and said selected pulse width modulation to eliminate said instability in said output voltage.

9. The method of claim 8 wherein said current control is said peak current control.

10. The method of claim 9 wherein said pulse width modulation for eliminating said instability is said leading-edge pulse width modulation.

11. The method of claim 8 wherein said current control method is said average current control.

12. The method of claim 11 wherein said pulse width modulation for eliminating said instability is said triangular pulse width modulation.

13. A method for producing a controlled output voltage for a switching power converter under predictive digital current control and using pulse width modulation, said method comprising:

selecting one of a peak current control and an inherently unstable average current control as said predictive digital current control resulting in an unstable output voltage;

selecting one of a leading-edge pulse width modulation and a triangular pulse width modulation as said pulse width modulation to eliminate said instability in said output voltage;

wherein

said predictive digital current control comprises;

sampling an input current at the beginning of each next switching cycle; and

predicting a next duty cycle of a pulsating control signal to generate a next duty cycle control signal; and

said pulse modulation comprises applying said next duty cycle control signal to a pulse width modulation signal corresponding to said selected one of said leading-edge pulse width modulation and said triangular pulse width modulation to generate said pulsating control signal.

14. The method of claim 13 wherein said current control is a peak current control and said pulse width modulation method is a leading-edge pulse width modulation.

15. The method of claim 13 wherein said current control is an average current control and said pulse width modulation is a triangular pulse width modulation.

16. A switching power converter for controlling an output voltage under current control using pulse width modulation comprising:

a predictive digital current-mode controller under one of a peak current control and an average current control for predicting a next duty cycle of a pulsating control signal and generating a control signal in said switching power converter; and

a pulse width modulator for producing said pulsating control signal by applying said control signal to one of a leading-edge pulse width modulation and a triangular pulse width modulation to produce a stable output voltage from said switching power converter.

17. The switching power converter of claim 16 wherein said predictive digital current-mode controller is a predictive digital peak current controller.

18. The switching power converter of claim 17 wherein said pulse width modulator uses a leading-edge pulse width modulation to produce said stable output voltage.

19. The switching power converter of claim 16 wherein said predictive digital current-mode controller is a predictive digital average current controller.

20. The switching power converter of claim 19 wherein said pulse width modulator uses a triangular pulse width modulation to produce said stable output voltage.