公开(公告)号：US20240128876A1

公开(公告)日：2024-04-18

申请号：US18335195

申请日：2023-06-15

Applicant: Richtek Technology Corporation

Inventor： Yu-Chang Chen ,  Ta-Yung Yang ,  Kun-Yu Lin ,  Fu-Ciao Syu ,  Chia-Hsien Yang ,  Hsin-Yi Wu

IPC: H02M3/335 ,  H02M1/08

CPC classification number: H02M3/33507 ,  H02M1/083

Abstract: A switching control circuit for use in controlling a resonant flyback power converter generates a first driving signal and a second driving signal. The first driving signal is configured to turn on the first transistor to generate a first current to magnetize a transformer and charge a resonant capacitor. The transformer and charge a resonant capacitor are connected in series. The second driving signal is configured to turn on the second transistor to generate a second current to discharge the resonant capacitor. During a power-on period of the resonant flyback power converter, the second driving signal includes a plurality of short-pulses configured to turn on the second transistor for discharging the resonant capacitor. A pulse-width of the short-pulses of the second driving signal is short to an extent that the second current does not exceed a current limit threshold.

公开(公告)号：US20250030337A1

公开(公告)日：2025-01-23

申请号：US18433417

申请日：2024-02-06

Applicant: Richtek Technology Corporation

Inventor： Kun-Yu Lin ,  Hsin-Yi Wu ,  Yu-Chang Chen ,  Fu-Ciao Syu ,  Chia-Hsien Yang ,  Chien-Fu Tang ,  Ta-Yung Yang

IPC: H02M3/00 ,  H02M1/00 ,  H02M1/08 ,  H02M3/335

Abstract: A circuit of a resonant power converter comprising: a high-side switch and a low-side switch, coupled to form a half-bridge switching circuit which is configured to switch a transformer for generating an output voltage; a high-side drive circuit, generating a high-side drive signal coupled to drive the high-side switch in response to a high-side control signal; a bias voltage, coupled to a bootstrap diode and a bootstrap capacitor providing a power source from the bootstrap capacitor for the high-side drive circuit; wherein the high-side drive circuit generates the high-side drive signal with a fast slew rate to turn on the high-side switch when the high-side switch is to be turned on with soft-switching; the high-side drive circuit generates the high-side drive signal with a slow slew rate to turn on the high-side switch when the high-side switch is to be turned on without soft-switching.