High-efficiency power converter system

• US 20080002444A1
• Filed: 06/30/2006
• Published: 01/03/2008
• Est. Priority Date: 06/30/2006
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Fairchild Semiconductor Corporation (ON Semiconductor Corporation)
• Inventors: Shekhawat, Sampat, Cho, Donghye, Randall, Ronald H.
• Granted Patent: US 7,518,895 B2
• Time in Patent Office: Days
• US Class Current: 363/127
• CPC Class Codes: H02M 1/0085 Partially controlled bridges
• CPC Class Codes: H02M 1/34 Snubber circuits
• CPC Class Codes: H02M 1/4225 using a non-isolated boost converter
• 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

In one embodiment, a power converter system includes a first input terminal and a second input terminal operable to connect to an alternating current (AC) power source, and an output terminal at which an output voltage can be provided to a load. A first inductor and a first diode are connected in series between the first input terminal and the output terminal. A second inductor and a second diode are connected in series between the second input terminal and the output terminal. A first switch is connected to the first inductor and the first diode, and a second switch is connected to the second inductor and the second diode. The first switch and the second switch alternately function as a boost switch and a synchronous rectifier for charging and discharging the first and second inductors during operation of the power converter system. An auxiliary network is operable to provide for zero voltage switching (ZVS) and zero current switching (ZCS) conditions for both the first and second switches during operation of the power converter system.

Claims

1. A power converter system comprising:

a first input terminal and a second input terminal operable to connect to an alternating current (AC) power source;

an output terminal at which an output voltage can be provided to a load;

a first inductor and a first diode connected in series between the first input terminal and the output terminal;

a second inductor and a second diode connected in series between the second input terminal and the output terminal;

a first switch connected to the first inductor and the first diode;

a second switch connected to the second inductor and the second diode;

wherein the first switch and the second switch alternately function as a boost switch and a synchronous rectifier for charging and discharging the first and second inductors during operation of the power converter system; and

an auxiliary network operable to provide for zero voltage switching (ZVS) and zero current switching (ZCS) conditions for both the first and second switches during operation of the power converter system.

2. The power converter system of claim 1 wherein the auxiliary network comprises:

a third switch; and

a third inductor connected at one end to the first and second inductors and at another end to the third switch;

wherein during operation current from the third inductor circulates through the third switch and backwards through a body diode of the first or second switch, thereby reducing the voltage drop across the first or second switch.

3. The power converter system of claim 2 wherein the auxiliary network comprises a capacitor and a third diode connected in parallel to the third inductor.

4. The power converter system of claim 1 wherein the system is implemented on an integrated circuit (IC) device.

5. The power converter system of claim 1 comprising a controller for providing control signals to turn on and off the first and second switches.

6. The power converter system of claim 1 comprising circuitry detecting a zero voltage condition on the first switch or the second switch.

7. The power converter system of claim 1 comprising circuitry for providing power factor correction (PFC) control.

8. A power converter system comprising:

a first input terminal operable to connect to one end of an alternating current (AC) power source;

a second input terminal operable to connect to another end of the AC power source;

an output terminal at which an output voltage can be provided to a load;

a first boost inductor and a first boost diode connected in series between the first input terminal and the output terminal;

a second boost inductor and a second boost diode connected in series between the second input terminal and the output terminal;

a first switch operable to function as a boost switch to charge and discharge the first boost inductor during a first half cycle of the AC power source;

a second switch operable to function as a boost switch to charge and discharge the second boost inductor during a second half cycle of the AC power source; and

an auxiliary network operable to provide for zero voltage switching (ZVS) and zero current switching (ZCS) conditions for both the first and second switches during the first half cycle and the second half cycle, respectively, of the AC power source.

9. The power converter system of claim 8 wherein the auxiliary network comprises:

a third switch; and

a third inductor connected at one end to the first and second inductors and at another end to the third switch;

wherein during operation current from the third inductor circulates through the third switch and backwards through a body diode of the first or second switch, thereby reducing the voltage drop across the first or second switch.

10. The power converter system of claim 8 wherein the system is implemented on an integrated circuit (IC) device.

11. The power converter system of claim 8 comprising a controller for providing control signals to turn on and off the first and second switches.

12. The power converter system of claim 8 comprising circuitry detecting a zero voltage condition on the first switch or the second switch.

13. The power converter system of claim 8 comprising circuitry for providing power factor correction (PFC) control.

14. A power converter system comprising:

a first input terminal and a second input terminal operable to connect to an alternating current (AC) power source;

an output terminal at which an output voltage can be provided to a load;

a first inductor and a first diode connected in series between the first input terminal and the output terminal;

a second inductor and a second diode connected in series between the second input terminal and the output terminal;

a first switch connected to the first inductor and the first diode;

a second switch connected to the second inductor and the second diode;

wherein the first switch and the second switch alternately function as a boost switch and a synchronous rectifier for charging and discharging the first and second inductors during operation of the power converter system; and

means for providing for zero voltage switching (ZVS) and zero current switching (ZCS) conditions for both the first and second switches during operation of the power converter system.

15. The power converter system of claim 14 wherein the means for providing for ZVS and ZCS conditions comprises an auxiliary network.

16. The power converter system of claim 14 wherein the means for providing for ZVS and ZCS conditions comprises:

a third switch; and

a third inductor connected at one end to the first and second inductors and at another end to the third switch;

wherein during operation current from the third inductor circulates through the third switch and backwards through a body diode of the first or second switch, thereby reducing the voltage drop across the first or second switch.

17. The power converter system of claim 16 comprising a capacitor and a third diode connected in parallel to the third inductor.

18. The power converter system of claim 14 wherein the system is implemented on an integrated circuit (IC) device.

19. The power converter system of claim 14 comprising a controller for providing control signals to turn on and off the first and second switches.

20. The power converter system of claim 14 comprising circuitry detecting a zero voltage condition on the first switch or the second switch.

21. The power converter system of claim 14 comprising circuitry for providing power factor correction (PFC) control.