公开(公告)号：US20160105116A1

公开(公告)日：2016-04-14

申请号：US14879175

申请日：2015-10-09

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Kuang-Fu Chang ,  Tzu-Chen Lin ,  Chien-Fu Tang

IPC: H02M3/335

CPC classification number: H02M3/33523 ,  H02M2001/0032

Abstract: The present invention provides a flyback power converter with a programmable output and a control circuit and a control method thereof. The flyback power converter converts an input voltage to a programmable output voltage according to a setting signal, wherein the programmable output voltage switches between different levels. The flyback power converter includes: a transformer circuit, a power switch circuit, a current sense circuit, an opto-coupler circuit, and a control circuit. The control circuit adaptively adjusts an operation signal according to a level of the programmable output voltage, to maintain a same or relatively higher operation frequency of the operation signal when the programmable output voltage switches to a relatively lower level, so as to maintain a phase margin while supplying the same output current.

Abstract translation: 本发明提供具有可编程输出和控制电路的回扫功率转换器及其控制方法。 回扫功率转换器根据设置信号将输入电压转换为可编程输出电压，其中可编程输出电压在不同电平之间切换。 反激式功率转换器包括：变压器电路，功率开关电路，电流检测电路，光耦合器电路和控制电路。 控制电路根据可编程输出电压的电平自适应地调整操作信号，以在可编程输出电压切换到相对较低的电平时维持操作信号的相同或相对较高的操作频率，以便保持相位裕度 同时提供相同的输出电流。

公开(公告)号：US11489439B1

公开(公告)日：2022-11-01

申请号：US17468932

申请日：2021-09-08

Applicant: Richtek Technology Corporation

Inventor： Chien-Fu Tang ,  Tzu-Chen Lin ,  Ta-Yung Yang

IPC: H02M1/34 ,  H02M3/335 ,  H02M1/32 ,  H03K3/0233 ,  H02M1/00 ,  G05F1/575 ,  G05F3/18 ,  H02H9/04 ,  G01R19/165

Abstract: A spike suppression circuit includes a wide bandgap transistor, a first transistor, a clamping circuit, and a capacitor. The wide bandgap transistor is depletion-type. The first transistor is coupled in series with the wide bandgap transistor. The clamping circuit provides a voltage difference, and is coupled to a common node between the wide bandgap transistor and the first transistor. The capacitor provides a supply voltage for the clamping circuit. When the first transistor is turned off, the capacitor can recycle spike energy at the common node.

公开(公告)号：US11451154B2

公开(公告)日：2022-09-20

申请号：US17334745

申请日：2021-05-30

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Kun-Yu Lin ,  Tzu-Chen Lin ,  Wei-Hsu Chang ,  Ta-Yung Yang

IPC: H02M3/335 ,  H02M1/38

Abstract: A flyback power converter circuit includes: a power transformer, a primary side switch and a conversion control circuit. In a DCM, during a dead time, the conversion control circuit calculates an upper limit frequency corresponding to output current according to a frequency upper limit function, and obtains a frequency upper limit masking period according to a reciprocal of the upper limit frequency, wherein the frequency upper limit masking period is a period starting from when the primary side switch is turned ON. During an upper limit selection period, the conversion control circuit selects a valley among one or more valleys in a ringing signal related to a voltage across the primary side switch as an upper limit locked valley, so that the conversion control circuit once again turns ON the primary side switch at a beginning time point of the upper limit locked valley.

公开(公告)号：US11201554B2

公开(公告)日：2021-12-14

申请号：US16701124

申请日：2019-12-02

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Tzu-Chen Lin

IPC: H02M3/335 ,  H02M1/08

Abstract: A ZVS (zero voltage switching) control circuit for controlling a flyback power converter includes: a primary side controller circuit, for generating a switching signal to control a primary side switch; and a secondary side controller circuit, for generating a synchronous rectifier (SR) control signal to control a synchronous rectifier switch. The SR control signal includes an SR-control pulse and a ZVS pulse. The primary side controller circuit determines a trigger timing point of the switching signal according to a first waveform characteristic of a ringing signal, to control the primary side switch to be ON. The secondary side controller circuit determines a trigger timing point of the ZVS pulse according to a second waveform characteristic of the ringing signal, to control the synchronous rectifier switch to be ON for a predetermined ZVS time period, thereby achieving zero voltage switching of the primary side switch.

公开(公告)号：US20200280263A1

公开(公告)日：2020-09-03

申请号：US16701124

申请日：2019-12-02

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Tzu-Chen Lin

IPC: H02M3/335 ,  H02M1/08

Abstract: A ZVS (zero voltage switching) control circuit for controlling a flyback power converter includes: a primary side controller circuit, for generating a switching signal to control a primary side switch; and a secondary side controller circuit, for generating a synchronous rectifier (SR) control signal to control a synchronous rectifier switch. The SR control signal includes an SR-control pulse and a ZVS pulse. The primary side controller circuit determines a trigger timing point of the switching signal according to a first waveform characteristic of a ringing signal, to control the primary side switch to be ON. The secondary side controller circuit determines a trigger timing point of the ZVS pulse according to a second waveform characteristic of the ringing signal, to control the synchronous rectifier switch to be ON for a predetermined ZVS time period, thereby achieving zero voltage switching of the primary side switch.

公开(公告)号：US10566893B2

公开(公告)日：2020-02-18

申请号：US16134906

申请日：2018-09-18

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Ta-Yung Yang ,  Tzu-Chen Lin ,  Li-Di Luo ,  Pei-Sheng Tsu

IPC: H02M3/335 ,  H02M1/08 ,  H02M1/00

Abstract: A ZVS (zero voltage switching) control circuit for use in a flyback power converter includes a primary side controller circuit, a secondary side controller circuit, and a pulse transformer. In one switching cycle, a synchronous rectifier transistor is turned ON twice to generate a circulation current at the primary side winding, and after the synchronous rectifier transistor is turned OFF, the power transistor is turned ON for zero voltage switching. A synchronous signal coupled between the primary side and the secondary side is employed to synchronize the power transistor and the synchronous transistor. The synchronous signal also triggers an SR-ZVS pulse to turn ON the synchronous rectifier transistor for achieving the zero voltage switching when the power transistor is turned ON.

公开(公告)号：US20200036280A1

公开(公告)日：2020-01-30

申请号：US16247520

申请日：2019-01-14

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Ta-Yung Yang ,  Tzu-Chen Lin ,  Chien-Fu Tang

IPC: H02M1/08 ,  H02M3/335

Abstract: A ZVS (zero voltage switching) control circuit for use in a flyback power converter includes a primary side controller and a secondary side controller. The primary side controller generates a switching signal to control a power transformer through a power transistor to generate an output voltage. The secondary side controller generates an SR (synchronous rectifier) signal to control an SR transistor at a secondary side of the power transformer. The SR signal includes an SR-control pulse and a ZVS pulse. The SR-control pulse controls the SR transistor according to a demagnetizing period of the power transformer. The ZVS pulse determines the starting timing of the switching signal to achieve zero voltage switching for the power transistor. The secondary side controller generates the ZVS pulse after a delay time from when the power transformer is demagnetized. The delay time is determined according to an output load of the output voltage.

公开(公告)号：US10218280B2

公开(公告)日：2019-02-26

申请号：US15052444

申请日：2016-02-24

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Kuang-Fu Chang ,  Tzu-Chen Lin

IPC: H02M3/335 ,  H02M1/32 ,  H02M1/00

Abstract: The present invention discloses a power converter, a switch control circuit, and a short circuit detection method for current sensing resistor of the power converter. The power converter includes: a transformer, a power switch, a current sensing resistor and a switch control unit. The current sensing resistor has one end coupled to the power switch and another end coupled to ground. The switch control unit generates the operation signal to control the power switch. The switch control unit generates a first sample-and-hold voltage at a first time point and a second sample-and-hold voltage at a second time point according to a voltage across the current sensing resistor. When a voltage difference between the first sample-and-hold voltage and the second sample-and-hold voltage is smaller than a reference voltage, it is determined that a short circuit occurs in the current sensing resistor.

公开(公告)号：US10171001B2

公开(公告)日：2019-01-01

申请号：US15415360

申请日：2017-01-25

Applicant: Richtek Technology Corporation

Inventor： Chang-Yu Wu ,  Tzu-Chen Lin

IPC: H02M3/335 ,  H02M1/15 ,  H02M3/158 ,  H02M7/04 ,  H02M3/00 ,  H02M1/00

Abstract: An AC-to-DC power converter includes a rectifier for generating a rectified voltage based on an AC voltage; an input capacitor coupled between the rectifier and a fixed-voltage terminal; a first inductive element; a first auxiliary capacitor; a first switch coupled between the input capacitor and the first inductive element; a second switch coupled between the first inductive element and the fixed-voltage terminal; a circuitry node; an auxiliary switch for coupling between the circuitry node and the first auxiliary capacitor or between the first auxiliary capacitor and the fixed-voltage terminal; a first diode; a second diode; a control signal generating circuit for controlling the first switch and the second switch; and an auxiliary switch control circuit for controlling the auxiliary switch.

公开(公告)号：US10170923B2

公开(公告)日：2019-01-01

申请号：US15951759

申请日：2018-04-12

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Ta-Yung Yang ,  Jing-Meng Liu ,  Isaac Y. Chen ,  Tzu-Chen Lin

IPC: H02J7/00 ,  H02M3/158

Abstract: An adaptive buck converter of a charging cable includes: a power receiving interface for receiving a DC voltage and a cable current from a cable; a terminal communication interface for transmitting a charging voltage and a charging current to a connection terminal of the charging cable and for receiving a communication signal generated by a mobile device from the connection terminal; a power converting circuit for receiving the DC voltage and the cable current from the power receiving interface and for generating the charging voltage and the charging current; a monitor circuit arranged to operably detect the DC voltage or the cable current; and a data processing circuit configured for controlling the power converting circuit according to the communication signal. The data processing circuit further communicates with the mobile device through the terminal communication interface and the connection terminal in response to a detection result of the monitor circuit.