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公开(公告)号：US12184183B2
公开(公告)日：2024-12-31
申请号：US17673158
申请日：2022-02-16
Applicant: Richtek Technology Corporation
Inventor： Ta-Yung Yang , Ying-Chieh Su , Yu-Chang Chen
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.
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公开(公告)号：US20240120846A1
公开(公告)日：2024-04-11
申请号：US18300530
申请日：2023-04-14
Applicant: Richtek Technology Corporation
Inventor： Yu-Chang Chen , Ta-Yung Yang , Kun-Yu Lin , Hsin-Yi Wu
CPC classification number: H02M3/33571 , H02M1/083 , H02M3/01
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. During a DCM (discontinuous conduction mode) operation, the second driving signal includes a resonant pulse for demagnetizing the transformer and a ZVS (zero voltage switching) pulse for achieving ZVS of the first transistor. The resonant pulse is skipped when the output voltage is lower than a low-voltage threshold.
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3.发明申请公开(公告)号：US20220271674A1
公开(公告)日：2022-08-25
申请号：US17673062
申请日：2022-02-16
Applicant: Richtek Technology Corporation
Inventor： Ta-Yung Yang , Ying-Chieh Su , Yu-Chang Chen
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.
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公开(公告)号：US09755530B2
公开(公告)日：2017-09-05
申请号：US15144610
申请日：2016-05-02
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Li-Di Luo , Yu-Kai Chen , Yu-Chang Chen
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.
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5.发明授权公开(公告)号：US12136885B2
公开(公告)日：2024-11-05
申请号：US18436023
申请日：2024-02-08
Applicant: Richtek Technology Corporation
Inventor： Ta-Yung Yang , Ying-Chieh Su , Yu-Chang Chen
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.
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Patent Agency Ranking
公开(公告)号：US12062974B2
公开(公告)日：2024-08-13
申请号：US17716933
申请日：2022-04-08
Applicant: Richtek Technology Corporation
Inventor： Ta-Yung Yang , Yu-Chang Chen
CPC classification number: H02M1/0006 , H02M3/07 , H02M3/33523
Abstract: A switched capacitor converter circuit includes: a conversion capacitor; an output capacitor; and switches configured to switch the coupling configurations of the conversion capacitor and the output capacitor according to a level of the first power supply voltage of the switched capacitor converter circuit, to generate the second power supply voltage at the output capacitor according to the first power supply voltage. The second power supply voltage provides power to control the power converter circuit. When the first power supply voltage is higher than a high threshold, the switched capacitor converter circuit controls the second power supply voltage to be lower than the first power supply voltage. When the first power supply voltage is lower than a low threshold, the switched capacitor converter circuit controls the second power supply voltage to be higher than the first power supply voltage.
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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
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.
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8.发明授权公开(公告)号：US11962247B2
公开(公告)日：2024-04-16
申请号：US17673062
申请日：2022-02-16
Applicant: Richtek Technology Corporation
Inventor： Ta-Yung Yang , Ying-Chieh Su , Yu-Chang Chen
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.
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公开(公告)号：US11843321B2
公开(公告)日：2023-12-12
申请号：US17534538
申请日：2021-11-24
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Ta-Yung Yang , Wei-Hsu Chang , Yu-Chang Chen , Tsung-Wei Huang , Shui-Mu Lin
CPC classification number: H02M3/33592 , H02M1/08
Abstract: A control circuit for controlling a power supply circuit to provide power to a system device which includes a communication circuit includes: a pulse width modulation (PWM) controller configured to switch a transformer of the power supply circuit to generate a first output voltage; and a switched capacitor converter configured to generate a second output voltage according to the first output voltage. The second output voltage provides power to the communication circuit, wherein the communication circuit generates a power saving signal to control the PWM controller and the switched capacitor converter. When the power saving signal is enabled, the first output voltage is decreased and a duty ratio of the switched capacitor converter is increased.
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公开(公告)号：US20230216425A1
公开(公告)日：2023-07-06
申请号：US17840540
申请日：2022-06-14
Applicant: Richtek Technology Corporation
Inventor： Ta-Yung Yang , Yu-Chang Chen
CPC classification number: H02M7/219 , H02M1/0003 , H02M1/08
Abstract: A synchronous full-bridge rectifier circuit includes: a first high-side transistor, a first low-side transistor, a second high-side transistor and a second low-side transistor which are configured to generate a DC power source from an AC power source, wherein the first high-side transistor and the first low-side transistor are coupled to a live wire of the AC power source, and the second high-side transistor and the second low-side transistor are coupled to a neutral wire of the AC power source; a first detection transistor, coupled to the live wire and configured to generate a first detection signal; and a second detection transistor, coupled to the neutral wire configured to generate a second detection signal; wherein the first low-side transistor is turned on after the body-diode of the first low-side transistor is turned on; the second low-side transistor is turned on after the body-diode of the second low-side transistor is turned on.
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