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公开(公告)号：US09451661B2
公开(公告)日：2016-09-20
申请号：US15018309
申请日：2016-02-08
Applicant: Richtek Technology Corporation
Inventor： Tong-Cheng Jao , Yi-Wei Lee , Jiun-Hung Pan , Isaac Y. Chen
CPC classification number: H05B33/0845 , H05B33/083
Abstract: A linear LED driver includes a voltage supply terminal providing a driving voltage, at least one first transistor, each of which has an input terminal coupled to a respective LED, and a bleeder circuit. When the voltage of the output terminal of each of the at least one first transistor is lower than a first threshold and a power voltage is higher than a second threshold, the bleeder circuit will generate a bleeder current to discharge the voltage supply terminal so as to prevent the LEDs from flickering. The bleeder circuit detects the voltage of the output terminal of each of the at least one first transistor. Therefore, whether the LEDs are lighted up can be confirmed so that the bleeder current can be provided at properly time point.
Abstract translation: 线性LED驱动器包括提供驱动电压的电压供应端子，至少一个第一晶体管，每个第一晶体管具有耦合到相应LED的输入端子和泄放电路。 当所述至少一个第一晶体管中的每一个的输出端子的电压低于第一阈值并且电源电压高于第二阈值时，所述泄放电路将产生泄放电流以对所述电压供应端子进行放电，以便 防止LED闪烁。 泄放电路检测至少一个第一晶体管中的每一个的输出端子的电压。 因此，可以确认LED是否点亮，从而可以在正确的时间点设置泄放电流。
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公开(公告)号：US09024607B2
公开(公告)日：2015-05-05
申请号：US13789287
申请日：2013-03-07
Applicant: Richtek Technology Corporation
Inventor： Tsung-Hsi Yang , Isaac Y. Chen , Chien-Fu Tang , Jiun-Hung Pan
CPC classification number: H02M7/06 , H02M1/4225 , H02M3/156 , Y02B70/126
Abstract: A control circuit for a power converter has a current source, a sampling circuit, a signal processing circuit, a driving circuit, and a shared pin. The shared pin is used for coupling with a resistor and a switch. The current source, coupled with the shared pin, provides a current through the shared pin to the resistor in a first period. The sampling circuit, coupled with the shared pin, samples signals on the shared pin for generating a first sampling value and a second sampling value. The signal processing circuit, coupled with the sampling circuit, compares the first sampling value and the second sampling value. The driving circuit generates driving signals for conducting the switch. When the difference of the first sampling value and the second sampling value is less than a predetermined value, the signal processing circuit configures the driving circuit to intermittently conduct the switch in a second period.
Abstract translation: 用于功率转换器的控制电路具有电流源，采样电路，信号处理电路，驱动电路和共享引脚。 共享引脚用于与电阻和开关耦合。 与共享引脚耦合的电流源在第一周期内通过共享引脚提供电流到电阻器。 与共享引脚耦合的采样电路在共享引脚上采样信号以产生第一采样值和第二采样值。 与采样电路耦合的信号处理电路比较第一采样值和第二采样值。 驱动电路产生用于导通开关的驱动信号。 当第一采样值和第二采样值的差小于预定值时，信号处理电路将驱动电路配置为在第二周期内间歇地导通开关。
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公开(公告)号：US08717091B2
公开(公告)日：2014-05-06
申请号：US13796547
申请日：2013-03-12
Applicant: Richtek Technology Corporation
Inventor： Yung-Chih Lai , Isaac Y. Chen , Chien-Fu Tang , Jiun-Hung Pan
IPC: G05F1/10
CPC classification number: G05B21/02 , H02M3/156 , H02M2001/0003
Abstract: A control circuit for a power converter is disclosed, having a shared pin, a driving circuit, a current source, a sampling circuit, and a signal processing circuit. The shared pin is used for coupling with an output end of the power converter through a resistor. The driving circuit is used for conducting a switch of the power converter. The current source provides a current to the resistor through the shared pin. The sampling circuit samples the signal on the shared pin for generating a first sampling value and a second sampling value. When the difference between the first sampling value and the second sampling value is less than a predetermined value, the signal processing circuit configures the driving circuit to adjust at least one of the conduction time and the conduction frequency of the switch according to an output signal of the power converter received from the shared pin.
Abstract translation: 公开了一种用于功率转换器的控制电路，其具有共享引脚，驱动电路，电流源，采样电路和信号处理电路。 共享引脚用于通过电阻与功率转换器的输出端耦合。 驱动电路用于导通电源转换器的开关。 电流源通过共享引脚向电阻提供电流。 采样电路对共享引脚上的信号进行采样，以产生第一采样值和第二采样值。 当第一采样值和第二采样值之间的差小于预定值时，信号处理电路将驱动电路配置为根据输入信号的输入信号调整开关的导通时间和导通频率中的至少一个 从共享引脚接收功率转换器。
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公开(公告)号：US11297702B2
公开(公告)日：2022-04-05
申请号：US17060055
申请日：2020-09-30
Applicant: Richtek Technology Corporation
Inventor： Yu-Wen Chang , Leng-Nien Hsiu , Isaac Y. Chen
IPC: H05B45/10 , H05B45/325 , H05B45/37 , H03K3/356
Abstract: A dimmer interface circuit includes a buffer stage circuit and a PWM control circuit. The buffer stage circuit converts a dimming input signal to a dimming buffer signal. The buffer stage circuit includes: a power rail generation circuit, which generates a power rail according to the dimming input signal adaptively, so that the dimming input signal is between a high level voltage and a low level voltage of the power rail; and an amplification circuit, which receives the dimming input signal, to generate the dimming buffer signal. The power rail supplies electrical power to the amplification circuit, wherein the amplification circuit operates within a range between the high level voltage and the low level voltage. The PWM control circuit converts the dimming buffer signal to a PWM dimming signal, so as to adjust a brightness of an LED module.
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公开(公告)号：US20210270870A1
公开(公告)日：2021-09-02
申请号：US17115662
申请日：2020-12-08
Applicant: Richtek Technology Corporation
Inventor： Isaac Y. Chen , Chien-Fu Tang , Hsin-Yi Wu , Kai-Chuan Chan , Yu-Lin Yang
Abstract: A current sensing circuit having self-calibration includes two leads, a sensing element having a sensing resistance, and a sensing and calibration circuit. The sensing and calibration circuit senses and calibrates a sensing voltage of the sensing element, and senses a sensing current through the sensing element according to the sensing resistance and the sensing voltage, to generate a current sensing output signal. The sensing and calibration circuit includes two pads, a V2I circuit, a current mirror circuit and an I2V circuit. The sensing element has a first temperature coefficient (TC). The TC and/or the resistance of an adjusting resistor in the V2I circuit and an adjusting resistor in the I2V circuit are determined according to the first TC, such that the TC of the current sensing output signal is equal to 0.
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Patent Agency Ranking
公开(公告)号：US20210167691A1
公开(公告)日：2021-06-03
申请号：US16926726
申请日：2020-07-12
Applicant: Richtek Technology Corporation
Inventor： Isaac Y. Chen , Chien-Fu Tang , Jo-Yu Wang
Abstract: A low delay time power converter circuit includes a driver circuit and a load. The driver circuit generates a switching driving signal to control the load. The driver circuit includes a switching control circuit and an output stage circuit which includes a first power switch, a second power switch and an impedance adjusting circuit. When the switching control circuit controls the switching driving signal to a first voltage level at a first time point, the first power switch is turned ON and then is turned OFF after a predetermined period. When the switching control circuit controls the switching driving signal to a second voltage level at a second time point, the second power switch is turned ON. The time point when the first power switch is turned OFF is earlier than the second time point. A resistance of the impedance adjusting circuit is larger than a conductive resistance of the first power switch.
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17.发明申请公开(公告)号：US20210112639A1
公开(公告)日：2021-04-15
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: H05B45/10 , H05B45/325
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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18.发明申请公开(公告)号：US20200099307A1
公开(公告)日：2020-03-26
申请号：US16541293
申请日：2019-08-15
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Li-Di Lo , Chien-Fu Tang , Isaac Y. Chen
Abstract: Whether a synchronous signal includes a synchronous pulse is determined by detecting whether there is a positive pulse higher than a positive threshold followed by a negative pulse lower than a negative threshold. The pulse signal detection method includes: comparing the synchronous signal with the positive threshold; comparing the synchronous signal with the negative threshold; and determining that the synchronous pulse exists when the positive pulse of the synchronous signal is higher than the positive threshold and the negative pulse of the synchronous signal is lower than the negative threshold in a post detection period after the positive pulse of the synchronous signal is determined higher than the positive threshold.
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公开(公告)号：US10236781B2
公开(公告)日：2019-03-19
申请号：US16012288
申请日：2018-06-19
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Isaac Y. Chen
Abstract: A power converter determines a feedback signal according to a voltage signal related to an output voltage of the power converter and a reference voltage, thereby regulating the output voltage. A control circuit and method for programming the output voltage of the power converter utilize an offset current generator to inject a current or sink a current for changing the voltage signal or the reference signal, thereby adjusting the output voltage. As a result, it gets rid of complicated circuitry but provides more steps adjustment, which reduces related costs.
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公开(公告)号：US10097094B2
公开(公告)日：2018-10-09
申请号：US14920078
申请日：2015-10-22
Applicant: RICHTEK TECHNOLOGY CORPORATION
Inventor： Isaac Y. Chen
Abstract: A power converter determines a feedback signal according to a voltage signal related to an output voltage of the power converter and a reference voltage, thereby regulating the output voltage. A control circuit and method for programming the output voltage of the power converter utilize an offset current generator to inject a current or sink a current for changing the voltage signal or the reference signal, thereby adjusting the output voltage. As a result, it gets rid of complicated circuitry but provides more steps adjustment, which reduces related costs.
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