公开(公告)号：US20240120844A1

公开(公告)日：2024-04-11

申请号：US18298340

申请日：2023-04-10

Applicant: Richtek Technology Corporation

Inventor： Kun-Yu LIN ,  Ta-Yung YANG ,  Yu-Chang CHEN ,  Hsin-Yi WU ,  Fu-Ciao SYU ,  Chia-Hsien YANG

IPC: H02M3/335 ,  H02M1/00 ,  H02M1/32 ,  H02M3/00

CPC classification number: H02M3/33571 ,  H02M1/0009 ,  H02M1/32 ,  H02M3/01 ,  H02M3/33592

Abstract: A resonant flyback power converter includes: a first and a second transistors which form a half-bridge circuit for switching a transformer and a resonant capacitor to generate an output voltage; a current-sense device for sensing a switching current of the half-bridge circuit to generate a current-sense signal; and a switching control circuit generating a first and a second driving signals for controlling the first and the second transistors. The turn-on of the first driving signal controls the half-bridge circuit to generate a positive current to magnetize the transformer and charge the resonant capacitor. The turn-on of the second driving signal controls the half-bridge circuit to generate a negative current to discharge the resonant capacitor. The switching control circuit turns off the first transistor when the positive current exceeds a positive-over-current threshold, and/or, turns off the second transistor when the negative current exceeds a negative-over-current threshold.