Switching power supply device

• US 7,348,766 B2
• Filed: 05/25/2006
• Issued: 03/25/2008
• Est. Priority Date: 06/03/2005
• Status: Expired due to Fees

• Current Assignee: Collabo Innovations, Inc. (Wi-LAN Inc.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hachiya, Yoshiaki, Arakawa, Ryutaro, Fukui, Minoru, Kunimatsu, Takashi
• Primary Examiner(s): Laxton, Gary L.
• Application Number:
  US11/441,374
• Publication Number:
  US 20060273662A1
• Time in Patent Office: 670 Days
• Field of Search: 323/224, 323/271, 323/282, 323/284, 323/351, 323/223, 323/285
• US Class Current: 323/284
• CPC Class Codes: B23K 9/1056 by using digital means B23K9/1068 takes precedence

Abstract

The peak current flowing to the switching device drops in a no-load state with PWM control, but because the number of switching operations is constant regardless of the load, further reducing power consumption is difficult. The switching power supply device has a PWM signal generator for generating a PWM signal, a switching device Q1 for switching the first supply voltage VIN based on the PWM signal, converters for outputting the difference between a second supply voltage and a reference voltage as a difference signal, and an intermittent oscillation control circuit for stopping the switching operation of the first switching device when the difference signal is less than a predetermined first threshold value (Vp1). The PWM signal generator changes the pulse width based on the difference signal to generate the PWM signal.

Claims

1. A switching power supply device comprising:

a first source voltage supply arrangement operable to supply a first supply voltage;

a PWM signal generator operable to generate a PWM signal;

a first switching arrangement operable to switch the first supply voltage based on the PWM signal;

a converter operable to convert the switched first supply voltage to a second supply voltage;

a difference signal detector operable to output the difference between the second supply voltage and a predetermined reference voltage as a difference signal;

an intermittent controller operable to stop the switching operation of the first switching arrangement when the difference signal is less than or equal to a first threshold value;

a current converter operable to convert the difference signal to a current signal; and

a voltage converter operable to convert the current-converted difference signal to a voltage signal;

wherein the PWM signal generator varies the pulse width of the PWM signal based on the voltage-converted difference signal and generates the PWM signal.

2. The switching power supply device described in claim 1, further comprising:

a first regulator operable to convert the first supply voltage to a predetermined third supply voltage, and to supply the third supply voltage to the PWM signal generator and voltage converter; and

a second regulator operable to convert the second supply voltage to a predetermined fourth supply voltage, and to supply the fourth supply voltage to the difference signal detector and current converter.

3. The switching power supply device described in claim 2, further comprising:

a first capacitor connected to the output node of the first regulator.

4. The switching power supply device described in claim 1, further comprising:

an inversion signal generator operable to generate an inverted signal of the PWM signal; and

a second switching arrangement connected to the first switching arrangement;

wherein the second switching arrangement switches based on the inversion signal.

5. The switching power supply device described in claim 2, wherein the second regulator converts the first supply voltage to the fourth supply voltage.

6. The switching power supply device described in claim 1, wherein the intermittent controller restarts the switching operation when the difference signal goes to a second threshold value or above while the switching operation is stopped.

7. The switching power supply device described in claim 2, further comprising:

a circuit having a first diode and a zener diode connected in series;

wherein the series circuit converts the second supply voltage to the third supply voltage.

8. The switching power supply device described in claim 2, further comprising:

a second diode connected to an input terminal of the voltage converter.

9. The switching power supply device described in claim 1, wherein the first switching arrangement is a high voltage transistor.

10. The switching power supply device described in claim 1, wherein the converter comprises a third diode, a coil, and an output capacitor.

11. The switching power supply device described in claim 1, further comprising an overcurrent protection circuit.

12. The switching power supply device described in claim 1, further comprising an overheating protection circuit.

13. The switching power supply device described in claim 1, wherein the converter outputs a second supply voltage of the same polarity as the first supply voltage.

14. The switching power supply device described in claim 1, wherein the converter outputs a second supply voltage of opposite polarity to the first supply voltage.

15. A switching power supply device comprising:

a first source voltage supply arrangement operable to supply a first supply voltage;

a PWM signal generator operable to generate a PWM signal;

a first switching arrangement operable to switch the first supply voltage based on the PWM signal;

a converter operable to convert the switched first supply voltage to a second supply voltage;

a difference signal detector operable to output the difference between the second supply voltage and a predetermined reference voltage as a difference signal;

a current converter operable to convert the difference signal to a current signal;

a voltage converter operable to convert the current signal to a voltage-converted difference signal;

a first regulator operable to convert the first supply voltage to a predetermined third supply voltage, and to supply the third supply voltage to the PWM signal generator and voltage converter; and

a second regulator operable to convert the second supply voltage to a predetermined fourth supply voltage, and to supply the fourth supply voltage to the difference signal detector and current converter;

wherein the PWM signal generator varies a pulse width of the PWM signal based on the voltage-converted difference signal and generates the PWM signal.

16. The switching power supply device described in claim 15, further comprising:

a first capacitor connected to the output node of the first regulator.

17. The switching power supply device described in claim 15, further comprising:

an inversion signal generator operable to generate an inverted signal of the PWM signal; and

a second switching arrangement connected to the first switching arrangement;

wherein the second switching arrangement switches based on the inversion signal.

18. The switching power supply device described in claim 15, wherein the second regulator converts the first supply voltage to the fourth supply voltage.

19. The switching power supply device described in claim 15, further comprising an intermittent controller operable to stop the switching operation of the first switching arrangement when the difference signal is less than or equal to a first threshold value.

20. The switching power supply device described in claim 19, wherein the intermittent controller restarts the switching operation when the difference signal goes to a second threshold value or above while the switching operation is stopped.

21. The switching power supply device described in claim 15, further comprising:

a circuit having a first diode and a zener diode connected in series;

wherein the series circuit converts the second supply voltage to the third supply voltage.

22. The switching power supply device described in claim 15, further comprising:

a second diode connected to an input terminal of the voltage converter.

23. The switching power supply device described in claim 15, wherein the first switching arrangement is a high voltage transistor.

24. The switching power supply device described in claim 15, wherein the converter comprises a third diode, a coil, and an output capacitor.

25. The switching power supply device described in claim 15, further comprising an overcurrent protection circuit.

26. The switching power supply device described in claim 15, further comprising an overheating protection circuit.

27. The switching power supply device described in claim 15, wherein the converter outputs a second supply voltage of the same polarity as the first supply voltage.

28. The switching power supply device described in claim 15, wherein the converter outputs a second supply voltage of opposite polarity to the first supply voltage.