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公开(公告)号：US12119749B2
公开(公告)日：2024-10-15
申请号：US17974437
申请日：2022-10-26
发明人： Guoqiang Liu , Yingyan He
IPC分类号： H02M3/335
CPC分类号： H02M3/33507
摘要： A flyback converter, a constant-current control method, and a lighting system are provided. The constant-current control method includes: sampling a loop current in a resonant loop to obtain a first sampling signal; obtaining zero crossing time of an excitation current in the resonant loop; and turning off a first switch tube when the first sampling signal reaches a reference value, and turning off a second switch tube after the zero crossing time of the excitation current in the resonant loop to control an average value of the excitation current to keep constant. The present disclosure can achieve a constant average value of an excitation current in each switching cycle based on a loop current in a resonant loop on the primary side of the converter, thereby realizing constant-current control of an output current of the converter.
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公开(公告)号：US12107413B2
公开(公告)日：2024-10-01
申请号：US17692702
申请日：2022-03-11
发明人： Aimin Xu
CPC分类号： H02H7/1213 , H02H1/0007
摘要： Disclosed is a switch protection circuit and a power converter, configured to set upper and lower limit-value current signals which can be adjusted along with an input voltage, so that instantaneous power of a main power switch can be prevented from being too high, and the main power switch can always be operated within a safe operating range, thereby solving the problem that the power converter is easy to be damaged in applications under a high-current circumstance.
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公开(公告)号：US20240120831A1
公开(公告)日：2024-04-11
申请号：US18478829
申请日：2023-09-29
发明人： Xianghua JIANG , Junming ZHANG , PITLEONG WONG , XIANGYONG XU
CPC分类号： H02M1/322 , H02M3/33507 , H02M3/3353
摘要： Disclosed is a protection circuit of a flyback converter and a control method. The protection circuit comprises: an active discharge module, connected to at least one end of a first capacitor in a resonance circuit of the flyback converter to provide a discharge path, and controlling turning-on and turning-off of the discharge path according to the discharge enable signal; in a normal work state, the discharge path is disconnected, the first capacitor works as a resonance capacitor; before the flyback converter is restarted, the discharge path is turned on for a predetermined time period to release charges of the first capacitor, a resonance current after the flyback converter is restarted is reduced to a safe work current of the second switch transistor. Charges stored in the first capacitor can be discharged to release before the flyback converter is restarted to reduce the resonance current and enhance system stability and security.
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公开(公告)号：US20240072655A1
公开(公告)日：2024-02-29
申请号：US18235362
申请日：2023-08-18
发明人： Pitleong WONG , Weijun MAO
摘要： A supply circuit and a switched mode power supply (SMPS) are provided. The supply circuit includes a first capacitor, a second capacitor, and a charging-discharging control circuit; the first capacitor includes a first terminal connected to a switching node, and a second terminal for providing a first supply voltage; the second capacitor includes a first terminal connected to a reference ground or a first potential terminal under control of the charging-discharging control circuit, and a second terminal for providing a second supply voltage; and according to a charging-discharging enable signal, the charging-discharging control circuit charges the second capacitor in a first time period and discharges the second capacitor in a second time period.
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公开(公告)号：US11894457B2
公开(公告)日：2024-02-06
申请号：US17315353
申请日：2021-05-09
发明人： Weiwei Ge
CPC分类号： H01L29/7825 , H01L29/0865 , H01L29/1095 , H01L29/66704
摘要： Disclosed is a semiconductor device and a method for manufacturing the same. The semiconductor device comprises a drift region on a substrate, a well region on the drift region, a source-end doped region in the well region, a drain-end doped region on the drift region, and a gate structure which is located between a source end and a drain end, located at a position of the well region, and forms a channel region in the well region. The source-end doped region comprises a first doped region and a second doped region with opposite doping types, the channel region connects the first doped region and the drift region. The first doped region and the second doped region of the source end are equivalently close to the gate structure, a distance between the second doped region and a PN junction surface formed by the drift region and the well region is reduced.
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公开(公告)号：US11805581B2
公开(公告)日：2023-10-31
申请号：US17953113
申请日：2022-09-26
发明人： Wanyue He , Guoqiang Liu
IPC分类号： H05B45/10 , H05B45/327 , H05B45/3725
CPC分类号： H05B45/10 , H05B45/327 , H05B45/3725
摘要： A buffer circuit for an LED driver circuit, a LED driver circuit, and a control method, the buffer circuit includes a first control switch connected in series in a rectified input loop and a feedback control module connected to the rectified input loop to obtain a loop current in the rectified input loop for generating a first control signal to the first control switch according to the loop current and a reference signal. The first control switch switches between a fully conducting state and a non-fully-conducting state based on the first control signal and restrains the loop current when the first control switch is in the non-fully-conducting state. The buffer circuit enhances the effect of restraining the current change rate and can effectively restrain current spikes in a circuit, resulting in higher safety and reliability.
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公开(公告)号：US20230328854A1
公开(公告)日：2023-10-12
申请号：US18128250
申请日：2023-03-30
发明人： Pitleong WONG
IPC分类号： H05B45/14 , H05B45/325
CPC分类号： H05B45/14 , H05B45/325
摘要： A dimming method and a dimming circuit for driving LED load are provided. The dimming circuit includes a power stage circuit, and the power stage circuit includes a power switch transistor. After the power stage circuit enters the DCM working mode, it obtains a first integral value according to the inductance current in a switch period of the power switch transistor, and obtains second time according to the first integral value and a duty cycle of a PWM dimming signal; when the switch period reaches the second time, the power switch transistor is controlled to be turned on to start the next switch period; a first upper limit voltage is set to a fixed voltage; the power switch transistor is controlled to be turned off when a sampling signal of the inductance current representing the inductance current of the power stage circuit reaches the first upper limit voltage.
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公开(公告)号：US20230143637A1
公开(公告)日：2023-05-11
申请号：US17978912
申请日：2022-11-01
发明人： Hao LONG
CPC分类号： H02M1/0045 , H02M1/0054 , H02M3/1582
摘要： A switched-mode power supply includes a first switch transistor. A drain of the first switch transistor receives an input voltage on a direct current input bus of the switched-mode power supply, and a source is connected to a reference ground. The power supply circuit includes a junction field-effect transistor (JFET), where a drain of the JFET receives the input voltage, a gate is connected to the reference ground, and a source outputs a supply voltage or a supply current. During each switch cycle, the first switch transistor is controlled to be turned off or a drain voltage is controlled to be greater than or equal to a first threshold voltage when the first switch transistor is turned on, such that the supply voltage or the supply current satisfies a drive voltage of the first switch transistor and an operating voltage of a to-be-powered circuit of the switched-mode power supply.
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公开(公告)号：US20220385283A1
公开(公告)日：2022-12-01
申请号：US17828045
申请日：2022-05-31
发明人： Xiangyong Xu
IPC分类号： H03K17/0812 , H03K17/687 , H02H9/04 , H03K17/74
摘要： A current limiting circuit of a switching circuit, and a switching circuit are provided. The switching circuit uses a gallium nitride (GaN) power transistor as a main power transistor. The current limiting circuit includes a first terminal connected with a drain of the GaN power transistor, and a second terminal connected with a controller of the switching circuit. The current limiting circuit is configured to limit a current flowing out of a power supply terminal of the controller. The current limiting circuit suppresses a negative current flowing through the controller.
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公开(公告)号：US20220181977A1
公开(公告)日：2022-06-09
申请号：US17544609
申请日：2021-12-07
发明人： Aimin XU
摘要： An inductive current simulation circuit of a switching circuit, an inductive current simulation method of the switching circuit, and a switched-mode power supply are provided. The inductive current simulation method includes the following steps: based on an error amplification circuit, performing, by the error amplification circuit, an error amplification on a first sampling signal representing a current of a synchronous rectifier and a second sampling signal representing an inductive current simulation signal when the synchronous rectifier is turned on to obtain an error amplification signal; and reconstructing an inductive current according to the error amplification signal when the synchronous rectifier is turned on and a first current when a main power transistor is turned on to obtain the inductive current simulation signal.
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