公开(公告)号：US10355612B2

公开(公告)日：2019-07-16

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

IPC: H02M3/335 ,  H02M1/36 ,  H02M1/32 ,  H02M1/08

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.

公开(公告)号：US20170196055A1

公开(公告)日：2017-07-06

申请号：US15216890

申请日：2016-07-22

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Tong-Cheng Jao ,  Isaac Y. Chen ,  Yi-Wei Lee ,  Wei-Ming Chiu ,  Jiun-Hung Pan

IPC: H05B33/08 ,  H05B37/02

CPC classification number: H05B33/0815 ,  H05B33/0809 ,  H05B33/0812 ,  H05B33/0827 ,  H05B33/0848 ,  H05B33/0851

Abstract: A light emitting device circuit has one or plural light emitting devices connected in series. A light emitting device driver circuit drives the light emitting device circuit according to a rectified input voltage. The light emitting device driver circuit includes a power switch and a control circuit. When the power switch is conductive, a light emitting device current flows through the light emitting device circuit and the power switch. When the power switch is not conductive, an output capacitor discharges to provide the light emitting device current. The control circuit determines whether the rectified input voltage is lower or not lower than a forward voltage plus a reference voltage according to a voltage at a reverse end of the light emitting device circuit, and control the power switch accordingly.

公开(公告)号：US10587312B1

公开(公告)日：2020-03-10

申请号：US16532531

申请日：2019-08-06

Applicant: Richtek Technology Corporation

Inventor： Tong-Cheng Jao ,  Yi-Wei Lee ,  Isaac Y. Chen

IPC: H01F27/42 ,  H04B5/00 ,  H04B15/02

Abstract: A transmission interface with noise reduction function includes a first circuit and a second circuit, for transmitting a signal from the first circuit to the second circuit or from the second circuit to the first circuit. The first circuit includes a first sub-winding and a first wire unit, and the second circuit includes a second sub-winding and a second wire unit. When an electromagnetic noise passes through the first sub-winding and the first wire unit, two loop currents are respectively generated, and the currents have opposite directions to cancel each other so as to reduce the electromagnetic noise. Or, when an emitting current corresponding to the signal flows through the first sub-winding and the first wire unit, two magnetic fields are respectively generated, and the magnetic fields have opposite directions to cancel each other so as to reduce the electromagnetic interference.

公开(公告)号：US20180309385A1

公开(公告)日：2018-10-25

申请号：US15632321

申请日：2017-06-24

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Jyun-Che Ho ,  Isaac Y. Chen ,  Yi-Wei Lee

IPC: H02M7/48 ,  H02M3/156 ,  H02M3/335 ,  G05F1/40 ,  H02M1/36

CPC classification number: H02M7/4807 ,  G05F1/40 ,  H02M1/36 ,  H02M3/156 ,  H02M3/335

Abstract: The invention provides a power conversion device, including: a voltage conversion stage, including a primary side for receiving a rectified voltage and a secondary side for generating a rectified voltage according to the rectified voltage, wherein the primary side includes a primary side switch; a switch control circuit having a startup status and a normal operation status, the switch control circuit being configured to operably provide a control signal to a control terminal of the primary side switch; a startup circuit, providing a current to the control terminal when the switch control circuit is in the startup status, to at least partially conduct the primary side switch; and a slow soft-startup circuit, wherein when the switch control circuit is in the startup status and the output voltage does not reach a predetermined voltage in a first predetermined time period, the slow soft-startup circuit reduces a total current quantity supplied to the control terminal in a second predetermined time period which is after the first predetermined time period.

公开(公告)号：US09755511B2

公开(公告)日：2017-09-05

申请号：US15076908

申请日：2016-03-22

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Yi-Wei Lee ,  Isaac Y. Chen

IPC: H02M1/08 ,  H02M3/157 ,  H02M3/156 ,  H02M1/14 ,  H05B33/08 ,  H03K17/16 ,  H02M1/00

CPC classification number: H02M3/156 ,  H02M1/08 ,  H02M1/14 ,  H02M2001/0009 ,  H02M2001/0048 ,  H03K17/166 ,  H03K2217/0027 ,  H05B33/0815 ,  H05B33/0824 ,  Y02B20/347 ,  Y02B70/1491

Abstract: The present invention discloses a current regulator circuit capable of reducing current ripple and a method of reducing current ripple. A power supply circuit generates a load current which originally has a current ripple. The load current is supplied to a load circuit. The current regulator circuit includes a regulator switch coupled to the load circuit, a current sense circuit for sensing the load current, and a control circuit. The control circuit controls the regulator switch to regulate a peak of a current sense signal minus an average of the current sense signal to a non-negative first predetermined value, or regulate the peak minus a valley of the current sense signal to a non-negative second predetermined value.

公开(公告)号：US10804883B2

公开(公告)日：2020-10-13

申请号：US16599082

申请日：2019-10-10

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Isaac Y. Chen ,  Yi-Wei Lee

IPC: G06F1/26 ,  H03K3/012 ,  H03K3/3562 ,  G06F13/40

Abstract: A power supply apparatus having multiple output ports includes: a master power supply circuit for supplying a master output power via a master power switch; a slave power supply circuit for supplying a slave output power via a slave power switch; and a shared resistor coupled between a power management node and a reference ground level. The slave sensing circuit outputs the slave sensing current via a slave power management pin, to generate a total power signal at the power management node. The master control circuit senses the total power signal via the master power management pin, to determine an adjustment current. The slave control circuit controls the slave power switch according to a voltage at the slave power management pin, to adjust the slave output power, so that a total power of the master output power and the slave output power does not exceed a predetermined power range.

公开(公告)号：US20200136593A1

公开(公告)日：2020-04-30

申请号：US16599082

申请日：2019-10-10

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Isaac Y. Chen ,  Yi-Wei Lee

IPC: H03K3/012 ,  G06F1/26 ,  G06F13/40 ,  H03K3/3562

Abstract: A power supply apparatus having multiple output ports includes: a master power supply circuit for supplying a master output power via a master power switch; a slave power supply circuit for supplying a slave output power via a slave power switch; and a shared resistor coupled between a power management node and a reference ground level. The slave sensing circuit outputs the slave sensing current via a slave power management pin, to generate a total power signal at the power management node. The master control circuit senses the total power signal via the master power management pin, to determine an adjustment current. The slave control circuit controls the slave power switch according to a voltage at the slave power management pin, to adjust the slave output power, so that a total power of the master output power and the slave output power does not exceed a predetermined power range.

公开(公告)号：US20170338663A1

公开(公告)日：2017-11-23

申请号：US15284643

申请日：2016-10-04

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Chang-Yu Wu ,  Yi-Wei Lee

IPC: H02J4/00 ,  H05B37/02 ,  H02M7/217

Abstract: The present invention provides a multi-load control apparatus, a slave circuit and a control method thereof. The multi-load control apparatus includes a master circuit and at least one slave circuit. The master circuit generates at least one pulse width modulation (PWM) signal according to an input signal. The slave circuit controls a power switch according to a corresponding PWM signal. The slave circuit has a primary side circuit and a secondary side circuit. The primary side circuit generates an AC PWM signal according to the corresponding PWM signal. The power switch has a control terminal which is driven according to a floating ground level which is not a constant voltage level. The power switch has a current inflow terminal and a current outflow terminal, which are connected to a corresponding load circuit in series, wherein the series circuit of the power switch and the load circuit receives an AC voltage.

公开(公告)号：US20170331381A1

公开(公告)日：2017-11-16

申请号：US15395641

申请日：2016-12-30

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Yi-Wei Lee ,  Chien-Yang Chen ,  Isaac Y. Chen ,  Ta-Yung Yang

IPC: H02M3/335 ,  H02M1/088 ,  H02M1/42 ,  H02M1/00

CPC classification number: H02M3/33507 ,  H02M1/088 ,  H02M1/4208 ,  H02M1/4225 ,  H02M1/4258 ,  H02M2001/0009 ,  H02M2001/4291 ,  H02M2003/1566

Abstract: The present invention provides a switching regulator with PFC function and a control circuit and a control method thereof. The switching regulator with PFC function includes a power stage circuit, a current sense circuit, and a control circuit. The power stage circuit operates at least one power switch therein according to an operation signal to convert an input voltage to an output voltage. When a transient voltage of the input voltage exceeds a transient voltage upper limit, or when a transient slew rate of the input voltage exceeds a transient slew rate upper limit, the control circuit adjusts a frequency response gain from a stable state frequency response gain to a transient state frequency response gain, such that a transient current of an output current does not exceed a current upper limit, and/or that a transient response time of the output current does not exceed a threshold transient time period.

公开(公告)号：US09781786B2

公开(公告)日：2017-10-03

申请号：US15008289

申请日：2016-01-27

Applicant: Richtek Technology Corporation

Inventor： Jyun-Che Ho ,  Isaac Y. Chen ,  Yi-Wei Lee

IPC: H05B33/08

CPC classification number: H05B33/0815 ,  H05B33/0848

Abstract: A control circuit of a LED driver utilizes a counter to acquire a cycle and a conduction time or a non-conduction time of an AC phase-cut voltage outputted by a TRIAC dimmer. A bleeding signal is determined according to the cycle and the conduction time or the non-conduction time and used for adjusting a bleeding current so as to avoid a flickering of the LED. The control circuit does not need extra pins for coupling a large capacitor, but the bleeding signal can be still acquired. Preferably, the present invention is suitable for an IC of low pin numbers.