Granted Patent B2

US 12,231,053 · App. 18/601,432 · Granted Feb 18, 2025

Inventors: Sheng-Yu Wen (Taoyuan, TW); Cheng-Yi Lin (Taoyuan, TW); Ting-Yun Lu (Taoyuan, TW)

Assignee: DELTA ELECTRONICS, INC.

H02M3/33592H02M1/0095H02M3/33571H02M3/33576

Abstract

Claims (38)

1. A power conversion circuit, configured to convert an input voltage into an output voltage, the power conversion circuit comprising:

a high-side switch and a low-side switch connected to the high-side switch,

a transformer, comprising a primary-side winding and a secondary-side winding,

a resonance tank, comprising an external inductance, an external capacitance, and the primary-side winding coupled in series, wherein the resonance tank is connected to the low-side switch in parallel,

a first switch, connected to the external inductance in parallel,

a second switch and a first capacitance forming a series-connected path, wherein the series-connected path is connected to the external capacitance in parallel, and

a third switch, connected to the secondary-side winding in series,

wherein when the power conversion circuit operates under a low-wattage output, the third switch is turned off, and the first switch and the second switch are turned on; when the power conversion circuit operates under a high-wattage output, the third switch is turned on, and the first switch and the second switch are turned off.

2. The power conversion circuit as claimed in claim 1 , further comprising:

a first synchronous rectification switch and a second synchronous rectification switch, respectively coupled to a first winding and a second winding of the secondary-side winding.

3. The power conversion circuit as claimed in claim 2 , wherein the third switch is connected to the second synchronous rectification switch.

4. The power conversion circuit as claimed in claim 2 , wherein under the low-wattage output, the first synchronous rectification switch is switched on, and the high-side switch and the low-side switch are switched on.

5. The power conversion circuit as claimed in claim 4 , further comprising a secondary-side control unit and a primary-side control unit,

the secondary-side control unit provides a first operation signal to turn off the third switch,

the primary-side control unit controls the high-side switch and the low-side switch switched on,

the primary-side control unit provides a second operation signal to turn on the first switch and the second switch, and

the secondary-side control unit provides a synchronous rectification signal to control the first synchronous rectification switch switched on.

6. The power conversion circuit as claimed in claim 2 , wherein under the high-wattage output, the first synchronous rectification switch and the second synchronous rectification switch are switched on, and the high-side switch and the low-side switch are switched on.

7. The power conversion circuit as claimed in claim 6 , further comprising a secondary-side control unit and a primary-side control unit,

the secondary-side control unit provides a first operation signal to turn on the third switch,

the primary-side control unit controls the high-side switch and the low-side switch switched on,

the primary-side control unit provides a second operation signal to turn off the first switch and the second switch, and

the secondary-side control unit provides a synchronous rectification signal to control the first synchronous rectification switch and the second synchronous rectification switch switched on.

8. The power conversion circuit as claimed in claim 1 , wherein the high-side switch is connected to a positive voltage end of the input voltage, and the low-side switch is connected to a negative voltage end of the input voltage.

9. The power conversion circuit as claimed in claim 1 , wherein under the low-wattage output, a voltage/current power output of the power conversion circuit is 5 to 15V/3 A or 20 to 28V/5 A; under the high-wattage output, the voltage/current power output of the power conversion circuit is 36 to 48V/10 A.

10. The power conversion circuit as claimed in claim 1 , wherein the capacitance value of the first capacitance and the capacitance value of the external capacitance have a proportional relationship of more than two times.

11. The power conversion circuit as claimed in claim 1 , further comprising:

a fourth switch, coupled to the secondary-side winding, and configured to control output of the output voltage.

12. The power conversion circuit as claimed in claim 1 , wherein from the operation under the low-wattage output to the operation under the high-wattage output, the duty cycles of the high-side switch and the low-side switch are preset to be 50%.

13. The power conversion circuit as claimed in claim 1 , further comprising:

a communication voltage generation circuit, configured to generate a communication voltage required for determining that the power conversion circuit operates under the low-wattage output and the high-wattage output.

14. The power conversion circuit as claimed in claim 13 , wherein the communication voltage generation circuit comprising:

a sixth switch, a first end of the sixth switch coupled to the first winding and the second winding,

a Zener diode, coupled to a control end of the sixth switch,

a resistor, coupled to a second end of the sixth switch and the Zener diode,

a diode, an anode of the diode coupled to the second end of the sixth switch and the resistor, and

a fifth switch, a first end of the fifth switch coupled to a cathode of the diode, and a second end of the fifth switch configured to provide the output voltage.

15. The power conversion circuit as claimed in claim 13 , wherein the communication voltage is 5-volt DC voltage.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (25)