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公开(公告)号：US10980090B1
公开(公告)日：2021-04-13
申请号：US16850958
申请日：2020-04-16
Applicant: Richtek Technology Corporation
Inventor： Yu-Min Chen , Isaac Y. Chen , Leng-Nien Hsiu
IPC: H05B37/00 , H05B45/10 , H05B45/325 , H05B45/385 , H05B45/38 , H05B45/375
Abstract: AN LED driving apparatus includes a power stage circuit and a dimming control circuit. The power stage circuit drives an LED circuit. The dimming control circuit includes a duty ratio conversion circuit, a digital-to analog conversion (DAC) circuit, an error amplifier (EA) circuit and a modulation control circuit. The duty ratio conversion circuit converts a PWM dimming signal to a digital duty ratio signal. The DAC circuit converts the digital duty ratio signal to an analog reference signal. The EA circuit generates an error amplified signal according to a difference between the analog reference signal and an output current related signal. The modulation control circuit generates a PWM control signal according to the error amplified signal, to control the power switch, such that the output current relates to a dimming duty ratio, whereby the dimming control circuit dims the LED circuit according to the PWM dimming signal.
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公开(公告)号：US10461652B2
公开(公告)日：2019-10-29
申请号：US16132367
申请日：2018-09-15
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Chien-Fu Tang , Jo-Yu Wang , Isaac Y. Chen
Abstract: A flyback power converter includes: a transformer, a power switch, a switch control unit, a synchronous rectifier switch and a secondary side control circuit. The secondary side control circuit includes: a switch signal generation circuit and a first power conversion circuit. The secondary side control circuit is coupled to the synchronous rectifier switch and the secondary winding of the transformer. The switch signal generation circuit generates the synchronous rectifier switch signal selectively according to a first power or a second power, to control the synchronous rectifier switch. The first power is related to the output voltage. The first power conversion circuit generates the second power according to a secondary phase signal on a phase node between the secondary winding of the transformer and the synchronous rectifier switch.
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公开(公告)号：US10461624B2
公开(公告)日：2019-10-29
申请号：US15485226
申请日：2017-04-11
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Pei-Sheng Tsu , Chien-Fu Tang , Isaac Y. Chen
Abstract: The present invention provides a power switch control circuit and an open detection method thereof. The power switch control circuit is for generating an operation signal at an operation signal output pin according to an input signal, wherein the operation signal is for operating a power switch. The power switch control circuit includes: a current injection circuit, which is connected to the operation signal output pin, and provides a predetermined current to the operation signal output pin according to an enable signal; and an open detection circuit, which is coupled to the current injection circuit, and determines whether a connection between the operation signal output pin and the power switch is open according to a level of the operation signal output pin at a detection time point or according to a level variation of the operation signal output pin during a detection time period, whereby an open detection signal is generated.
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公开(公告)号：US10326351B2
公开(公告)日：2019-06-18
申请号：US16123135
申请日：2018-09-06
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Li-Di Lo , Isaac Y. Chen , Chien-Fu Tang
Abstract: A switching regulator includes: a controller power ON reset (POR) circuit, a controller post-POR signal generation circuit, and a pulse width modulation (PWM) signal generation circuit. The controller post-POR signal generation circuit switches the controller post-POR signal to a ready level after a controller pre-POR signal is switched to a controller reset-accomplished level and a driver signal starts switching levels to operate a power switch. The PWM signal generation circuit sets a duty ratio of a PWM signal to a predetermined minimum duty ratio after the controller pre-POR signal is switched to the controller reset-accomplished level and before the controller post-POR signal is switched to a ready level.
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公开(公告)号：US20190140534A1
公开(公告)日：2019-05-09
申请号：US16123135
申请日：2018-09-06
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Li-Di Lo , Isaac Y. Chen , Chien-Fu Tang
Abstract: A switching regulator includes: a controller power ON reset (POR) circuit, a controller post-POR signal generation circuit, and a pulse width modulation (PWM) signal generation circuit. The controller post-POR signal generation circuit switches the controller post-POR signal to a ready level after a controller pre-POR signal is switched to a controller reset-accomplished level and a driver signal starts switching levels to operate a power switch. The PWM signal generation circuit sets a duty ratio of a PWM signal to a predetermined minimum duty ratio after the controller pre-POR signal is switched to the controller reset-accomplished level and before the controller post-POR signal is switched to a ready level.
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Patent Agency Ranking
公开(公告)号：US10181785B2
公开(公告)日：2019-01-15
申请号：US15874733
申请日：2018-01-18
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Yi-Min Shiu , Isaac Y. Chen
Abstract: The present invention discloses a short circuit and/or bad connection detection method for use in a power supply system. The power supply system includes a power converter which converts an input voltage to an output voltage and supplies an output current to an electronic device. In the short circuit detection method, the conversion from the input voltage to the output voltage is disabled in a disable time period, and whether a short circuit occurs is determined according to the decreasing speed of the output voltage. In the bad connection detection method, an actual voltage and an actual current received by the electronic device are compared with the output voltage and the output current, to determine whether a bad connection occurs.
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7.发明申请公开(公告)号：US20180375320A1
公开(公告)日：2018-12-27
申请号：US15909313
申请日：2018-03-01
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Jyun-Che Ho , Jo-Yu Wang , Isaac Y. Chen
Abstract: A buck switching regulator includes: a power stage, which includes: an upper-gate switch, a lower-gate switch and an inductor, connected with one another at a switching node; and a supply control switch, controlling the power supply form an output terminal to a load. An overvoltage protection method includes the following steps: (A) sensing a voltage of the switching node, to obtain a switching node voltage; (B) determining whether an overvoltage event occurs in the switching node voltage; and (C) if it is determined yes in the step (B), outputting a protection signal. An overvoltage event is determined directly according to the switching node voltage, not directly according to the output voltage.
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公开(公告)号：US20180212528A1
公开(公告)日：2018-07-26
申请号：US15865212
申请日：2018-01-08
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Chien-Fu Tang , Su-Yuan Lin , Yi-Wei Lee , Isaac Y. Chen
CPC classification number: H02M3/33592 , H02M1/08 , H02M1/32 , H02M1/36 , Y02B70/1475
Abstract: A flyback power converter circuit converting an input voltage to an output voltage includes a transformer, a power switch, a synchronous rectifier (SR) switch, and a secondary side control circuit. The secondary side control circuit controls the SR switch to be ON when the power switch is OFF. The secondary side control circuit includes a driving switch for controlling the SR switch, a synchronous control circuit powered by a voltage related to the output voltage, which controls the driving switch to operate the SR switch, and a clamping circuit including a clamping switch and a clamping switch control circuit. The clamping switch control circuit controls the clamping switch according to a current inflow terminal voltage of the clamping switch and/or the voltage related to the output voltage, such that, during a secondary side power-on period, an equivalent impedance of the current inflow terminal of the clamping switch is smaller than a predetermined clamping impedance.
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公开(公告)号：US09655185B2
公开(公告)日：2017-05-16
申请号：US14920240
申请日：2015-10-22
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Jiun-Hung Pan , Tong-Cheng Jao , Yi-Wei Lee , Isaac Y. Chen
IPC: H05B33/08
CPC classification number: H05B33/083 , Y02B20/341 , Y02B20/345
Abstract: A linear LED driver comprises a transistor having an input terminal coupled to a LED. When the transistor is turned on, the LED is lighted. The linear LED driver further includes a protection circuit for judging whether an instant high voltage variation occurs or not according to at least one of the voltages of a control terminal and an output terminal of the transistor so as to achieve a protection function.
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公开(公告)号：US20160315541A1
公开(公告)日：2016-10-27
申请号：US14695761
申请日：2015-04-24
Applicant: Richtek Technology Corporation
Inventor： Isaac Y. Chen
IPC: H02M3/335
CPC classification number: H02M3/33507 , H02H3/027 , H02H7/1213 , H02M3/33523 , H02M2001/0032 , H02M2001/325 , Y02B70/16
Abstract: A feedback signal stabilized by a capacitor and related to an output voltage of a power converter is used to acquire the output power information of the power converter, and a control circuit uses a second clock not related to the switching frequency of the power converter to count a duration time of the feedback signal being higher than a threshold. When the duration time is higher than a preset time, an abnormal output power of the power converter is distinguished and the power converter will be turned off. The feedback signal will not vary severely even if the output terminal of the power converter is interfered, and the counted duration time will not be influenced when the switching frequency is changing caused by a load changing.
Abstract translation: 使用由电容器稳定并与功率转换器的输出电压相关的反馈信号来获取功率转换器的输出功率信息，并且控制电路使用与功率转换器的开关频率无关的第二时钟来计数 反馈信号的持续时间高于阈值。 当持续时间高于预设时间时，功率转换器的异常输出功率被区分，功率转换器将被关闭。 即使电源转换器的输出端子受到干扰，反馈信号也不会严重变化，而当负载变化导致开关频率变化时，计数持续时间不会受到影响。
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