US 12,456,912 B2
Forward DC-DC ZVS converter and control scheme
Da Feng Weng, Sunnyvale, CA (US)
Assigned to Da Feng Weng, Sunnyvale, CA (US)
Filed by Da Feng Weng, Sunnyvale, CA (US)
Filed on Oct. 29, 2021, as Appl. No. 17/300,765.
Prior Publication US 2023/0140308 A1, May 4, 2023
Int. Cl. H02M 1/00 (2007.01); H02M 3/335 (2006.01); H05B 45/382 (2020.01)
CPC H02M 1/0058 (2021.05) [H02M 3/33553 (2013.01); H05B 45/382 (2020.01)] 5 Claims
OG exemplary drawing
 
1. A forward DC-DC ZVS converter comprising:
a function block, an output isolated transformer, and a related forward DC-DC converter;
wherein the output isolated transformer comprises a primary winding, a secondary winding, and a reset winding in tight couple through a magnetizing core; and the output isolated transformer comprises a magnetizing inductor; wherein the inductance value of the related magnetizing inductor is changed with turns-ratio square of the output isolated transformer; and two terminals of the secondary winding Ns are connected with the cathodes of the output diode D1 and the freewheel diode D2 separately; and the anodes of the output diode and the freewheel diode are connected together with negative terminals of an output filter capacitor Cf and the load; and the cathode of the freewheel diode is connected with one terminal of an output inductor, and the other terminal of the output inductor is connected with the positive terminals of output filter capacitor and the load;
wherein a first pin of the function block M is connected with a gate of a primary MOSFET; and a second pin of the function block M is connected with a gate of a second MOSFET; and a third pin of the function block M is connected with a source of the second MOSFET and ground; and a source of the primary MOSFET is connected through the sense resistor into ground; and the reset winding Nt and a resonant capacitor with a parallel diode are connected with the related pins of the function block;
wherein the function block comprises two parts, one part of the divided function block is configured to control the on or off of the primary MOSFET turn; and the other part of the divided function block is configured to control the on or off of the second MOSFET; and based on the current of the reset winding or the voltage of the resonant capacitor, feedback signal, the function block M is configured to control the resonant reset through control the on or off of the resonant reset second MOSFET;
wherein VIN is a primary side input DC voltage; and VIN is connected with the homonymous end primary winding of the output isolated transformer; and the non-homonymous end primary winding of the output isolated transformer is connected with the drain of the first MOSFET.