公开(公告)号：US10153703B2

公开(公告)日：2018-12-11

申请号：US15433761

申请日：2017-02-15

Applicant: RICHTEK TECHNOLOGY CORPORATION

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

IPC: H02M3/335 ,  H02M1/00

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.

公开(公告)号：US20180301974A1

公开(公告)日：2018-10-18

申请号：US15878483

申请日：2018-01-24

Applicant: RICHTEK TECHNOLOGY CORPORATION

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

IPC: H02M1/08 ,  H02M3/335

Abstract: A flyback power converter circuit includes: a transformer, including a primary winding coupled to an input power and a secondary winding coupled to an output node; a primary side switch coupled to the primary winding for switching the input power to generate an output power on the output node through the secondary winding; a clamping circuit including an auxiliary switch and an auxiliary capacitor which are connected in series to form an auxiliary branch which is connected with the primary winding in parallel; and a conversion control circuit adjusting an auxiliary dead time according to a primary side switch related signal and a switching voltage related signal such that the primary side switch is zero voltage switching at a time point when the primary side switch is turned ON.

公开(公告)号：US20160172962A1

公开(公告)日：2016-06-16

申请号：US14960403

申请日：2015-12-06

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Yu-Kai Chen ,  Hsin-Yi Wu ,  Tzu-Chen Lin

IPC: H02M1/16 ,  H02M3/335

CPC classification number: H02M3/33592 ,  H02M1/32 ,  H02M2001/0012 ,  Y02B70/1475

Abstract: The present invention discloses a flyback converter, a primary side control circuit therein, and a control method thereof. The flyback converter includes: a transformer circuit, a power switch circuit, a primary side control circuit, a synchronous rectification (SR) switch, and a synchronous rectification (SR) control circuit. When a feedback signal indicates that a difference between a target output voltage and an actual output voltage increases, the primary side control circuit increases an operation frequency of an operation signal by step-wisely reducing a cycle period of the operation signal in response to the increase of the difference, wherein the cycle period of the operation signal is reduced by a predetermined unit of time in each step, such that the cycle period of the operation signal is a step function of the increase of the difference.

Abstract translation: 本发明公开了一种反激式转换器，其中的一次侧控制电路及其控制方法。 反激式转换器包括：变压器电路，电源开关电路，初级侧控制电路，同步整流（SR）开关和同步整流（SR）控制电路。 当反馈信号表示目标输出电压和实际输出电压之间的差异增大时，初级侧控制电路通过逐步减小操作信号的循环周期来增加操作信号的操作频率，以响应于增加 的差别，其中在每个步骤中操作信号的周期周期减少预定的时间单位，使得操作信号的周期周期是差的增加的阶梯函数。

公开(公告)号：US08937470B2

公开(公告)日：2015-01-20

申请号：US13661892

申请日：2012-10-26

Applicant: Richtek Technology Corporation

Inventor： Tzu-Chen Lin

IPC: G05F1/00 ,  H02M1/42 ,  H02M1/00

CPC classification number: H02M1/4225 ,  H02M2001/0022 ,  H02M2001/0025 ,  Y02B70/126 ,  Y02P80/112

Abstract: An active power factor correction (PFC) circuit for calibrating a power factor of an AC-to-DC converter when the active PFC circuit is coupled with the AC-to-DC converter is disclosed including: a piecewise linear gain circuit, an error amplifier, a PWM controller, and a PWM signal generator. The piecewise linear gain circuit is for receiving a feed forward signal and generating a corresponding gain signal, wherein the gain signal and the feed forward signal have a broken line relation with respect to magnitude. The error amplifier is for generating an error signal according to an output voltage of the AC-to-DC converter. The PWM controller is for generating a control signal according to the gain signal and the error signal. The PWM signal generator is for generating a PWM signal for controlling a power switch of the AC-to-DC converter according to the control signal.

Abstract translation: 公开了一种用于在有源PFC电路与AC-DC转换器耦合时校准AC-DC转换器的功率因数的有功功率因数校正（PFC）电路，包括：分段线性增益电路，误差放大器 ，PWM控制器和PWM信号发生器。 分段线性增益电路用于接收前馈信号并产生相应的增益信号，其中增益信号和前馈信号相对于幅度具有虚线关系。 误差放大器用于根据AC-DC转换器的输出电压产生误差信号。 PWM控制器用于根据增益信号和误差信号产生控制信号。 PWM信号发生器用于根据控制信号产生用于控制AC-DC转换器的电源开关的PWM信号。