公开(公告)号：US20240223093A1

公开(公告)日：2024-07-04

申请号：US18436023

申请日：2024-02-08

Applicant: Richtek Technology Corporation

Inventor： Ta-Yung Yang ,  Ying-Chieh Su ,  Yu-Chang Chen

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

CPC classification number: H02M3/33571 ,  H02M1/0058 ,  H02M1/083 ,  H02M3/33592 ,  H02M1/0009

Abstract: A resonant half-bridge flyback power converter includes: a first transistor and a second transistor which form a half-bridge circuit; a transformer and a resonant capacitor connected in series and coupled to the half-bridge circuit; and a switching control circuit configured to generate a first driving signal and a second driving signal to control the first transistor and the second transistor respectively for switching the transformer to generate an output voltage. The first driving signal is configured to magnetize the transformer. The second driving signal includes at most one pulse between two consecutive pulses of the first driving signal. The switching control circuit generates a skipping cycle period when an output power is lower than a predetermined threshold. A resonant pulse of the second driving signal is skipped during the skipping cycle period. The skipping cycle period is increased in response to the decrease of the output power.

公开(公告)号：US12009753B2

公开(公告)日：2024-06-11

申请号：US17673298

申请日：2022-02-16

Applicant: Richtek Technology Corporation

Inventor： Ta-Yung Yang ,  Ying-Chieh Su ,  Yu-Chang Chen

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

CPC classification number: H02M3/33571 ,  H02M1/0058 ,  H02M1/083 ,  H02M3/33592 ,  H02M1/0009

Abstract: A half-bridge flyback power converter: a first transistor, a second transistor and a third transistor which form a half-bridge circuit. The first transistor is turned on for generating a negative circulated current for achieving zero voltage switching of the second transistor. The second transistor is turned on for magnetizing a transformer. The third transistor is turned on during a demagnetized time period to generate an output voltage. The physical size of the first transistor is smaller than physical size of the third transistor.

公开(公告)号：US20240120845A1

公开(公告)日：2024-04-11

申请号：US18300458

申请日：2023-04-14

Applicant: Richtek Technology Corporation

Inventor： Yu-Chang Chen ,  Ta-Yung Yang ,  Kun-Yu Lin ,  Hsin-Yi Wu

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

CPC classification number: H02M3/33571 ,  H02M1/083 ,  H02M3/01 ,  H02M3/33592

Abstract: A resonant flyback power converter includes: a first transistor and a second transistor which are configured to switch a transformer and a resonant capacitor for generating an output voltage; and a switching control circuit generating first and second driving signals for controlling the first and the second transistors. The turn-on of the first driving signal magnetizes the transformer. The second driving signal includes a resonant pulse having a resonant pulse width and a ZVS pulse during the DCM operation. The resonant pulse is configured to demagnetize the transformer. The resonant pulse has a first minimum resonant period for a first level of the output load and a second minimum resonant period for a second level of the output load. The first level is higher than the second level and the second minimum resonant period is shorter than the first minimum resonant period.

公开(公告)号：US20220271676A1

公开(公告)日：2022-08-25

申请号：US17673298

申请日：2022-02-16

Applicant: Richtek Technology Corporation

Inventor： Ta-Yung Yang ,  Ying-Chieh Su ,  Yu-Chang Chen

IPC: H02M3/335 ,  H02M1/00

Abstract: A half-bridge flyback power converter: a first transistor, a second transistor and a third transistor which form a half-bridge circuit. The first transistor is turned on for generating a negative circulated current for achieving zero voltage switching of the second transistor. The second transistor is turned on for magnetizing a transformer. The third transistor is turned on during a demagnetized time period to generate an output voltage. The physical size of the first transistor is smaller than physical size of the third transistor.

公开(公告)号：US20220271675A1

公开(公告)日：2022-08-25

申请号：US17673158

申请日：2022-02-16

Applicant: Richtek Technology Corporation

Inventor： Ta-Yung Yang ,  Ying-Chieh Su ,  Yu-Chang Chen

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

Abstract: A flyback power converter includes: a first transistor switching a transformer for generating a primary switching current and an output voltage; and a second transistor generating a circulated current to achieve ZVS (zero voltage switching) of the first transistor; wherein the flyback power converter actively forces at least one switching cycle to be operated in a DCM (discontinuous conduction mode) operation when the primary switching current is determined to have been operating in a non-DCM operation for a predetermined number of switching cycles. The flyback power converter generates a demagnetized signal which emulates the demagnetized time of the transformer for controlling the second transistor during the non-DCM operation. The flyback power converter calibrates the demagnetized signal according to the demagnetized time during the actively fored DCM operation.

公开(公告)号：US11139742B2

公开(公告)日：2021-10-05

申请号：US16879692

申请日：2020-05-20

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Wei-Hsu Chang ,  Ta-Yung Yang ,  Yu-Chang Chen ,  Chao-Chi Chen ,  Chuh-Ching Li ,  Li-Di Lo ,  Hao-Wen Chung

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

Abstract: A switching controller circuit for controlling a flyback power converter includes: a power transformer, a primary side controller circuit and a secondary side controller circuit. The power transformer is coupled between the input voltage and the output voltage in an isolated manner. The primary side controller circuit controls a primary side switch of the flyback power converter. The secondary side controller circuit generates a synchronous rectification (SR) signal, to control an SR switch of the flyback power converter. The SR signal includes an SR pulse and a soft switching (SS) pulse. The SR pulse controls the SR switch to be ON for an SR period, to achieve synchronous rectification at the secondary side. The SS pulse controls the SR switch to be ON for an SS period, to achieve soft switching of the primary side switch.

公开(公告)号：US20160344296A1

公开(公告)日：2016-11-24

申请号：US15144610

申请日：2016-05-02

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Li-Di Luo ,  Yu-Kai Chen ,  Yu-Chang Chen

IPC: H02M3/335 ,  H02M1/08

CPC classification number: H02M3/33523 ,  H02M1/08 ,  H02M3/33592 ,  Y02B70/1475

Abstract: The present invention discloses a power converter with synchronous control function and control method thereof. The power converter includes: a transformer, a power switch, a switch control unit, a signal coupling circuit, a synchronous rectifying switch and a secondary side control circuit. The switch control unit generates an operation signal according to a feedback signal, and generates a first synchronous signal which is related to the operation signal. The signal coupling circuit couples the first synchronous signal to generate a second synchronous signal. The synchronous rectifying switch is turned ON/OFF according to a synchronous rectifying switch signal, for synchronous rectification. The secondary side control circuit generates the synchronous rectifying switch signal according to a secondary side level detection signal and the second synchronous signal, to control the synchronous rectifying switch. The ON time of the power switch and the ON time of the synchronous rectifying switch do not overlap.

Abstract translation: 本发明公开了一种具有同步控制功能的电力转换器及其控制方法。 电力转换器包括：变压器，电源开关，开关控制单元，信号耦合电路，同步整流开关和次级侧控制电路。 开关控制单元根据反馈信号产生操作信号，并产生与操作信号相关的第一同步信号。 信号耦合电路耦合第一同步信号以产生第二同步信号。 同步整流开关根据同步整流开关信号导通/关断，用于同步整流。 次级侧控制电路根据次级侧电平检测信号和第二同步信号生成同步整流开关信号，以控制同步整流开关。 电源开关的接通时间和同步整流开关的接通时间不重叠。