公开(公告)号：US10924094B1

公开(公告)日：2021-02-16

申请号：US16558333

申请日：2019-09-03

Applicant: Power Forest Technology Corporation

Inventor： Yueh-Chang Chen

IPC: H03K3/017 ,  H03K5/04 ,  H03K7/08 ,  H03K5/05 ,  H03K5/22 ,  H03L7/22 ,  H03K19/20

Abstract: A pulse width modulation control circuit and a control method of a pulse width modulation signal are provided. A counter circuit generates a count value according to a phase-locked loop clock, and resets the count value according to a transition point of a synchronization signal. A comparison circuit compares the count value with a duty ratio set value, and sets the pulse width modulation signal to a high level while the count value is less than the duty ratio set value.

公开(公告)号：US20210036609A1

公开(公告)日：2021-02-04

申请号：US16831835

申请日：2020-03-27

Applicant: Power Forest Technology Corporation

Inventor： Tso-Min Chen

IPC: H02M3/155 ,  H01F27/34

Abstract: A voltage conversion apparatus is provided. A leakage inductance energy recovery circuit is coupled to a primary side auxiliary winding and a control circuit, and recovers leakage inductance energy of a transformer circuit to supply an operating power to the control circuit. Before a main switch is turned on the next time, leakage inductance energy recovered previously is used to lower a cross-voltage of the main switch, so that transient loss of conduction of the main switch is eliminated or reduced, and circuit efficiency is improved.

公开(公告)号：US10743380B2

公开(公告)日：2020-08-11

申请号：US16234531

申请日：2018-12-27

Applicant: Power Forest Technology Corporation

Inventor： Yang-Tai Tseng

IPC: H05B33/08 ,  H05B45/10 ,  H02M1/08 ,  H05B45/37 ,  H02M1/00

Abstract: A light emitting diode driving device and a light emitting diode backlight module are provided. A current is provided to a filter circuit by a controllable current source controlled by a dimming signal, so that the filter circuit generates a corresponding dimming voltage to control current flowing through a LED unit to dim the LED unit.

公开(公告)号：US20200120769A1

公开(公告)日：2020-04-16

申请号：US16234531

申请日：2018-12-27

Applicant: Power Forest Technology Corporation

Inventor： Yang-Tai Tseng

IPC: H05B33/08 ,  H02M1/08

Abstract: A light emitting diode driving device and a light emitting diode backlight module are provided. A current is provided to a filter circuit by a controllable current source controlled by a dimming signal, so that the filter circuit generates a corresponding dimming voltage to control current flowing through a LED unit to dim the LED unit.

公开(公告)号：US10177649B1

公开(公告)日：2019-01-08

申请号：US15694875

申请日：2017-09-04

Applicant: Power Forest Technology Corporation

Inventor： Po-Jen Ke

IPC: H02M1/32 ,  H02M3/335

Abstract: A power conversion apparatus and a synchronous rectification (SR) circuit thereof are provided. The power conversion apparatus includes a transformer and the SR circuit. A primary winding of the transformer receives an input voltage. A secondary winding of the transformer provides an output voltage to an output terminal. The SR circuit includes a SR transistor and a SR controller. The SR transistor is coupled between the secondary winding and the output terminal and controlled by a control signal. The SR controller is coupled to the SR transistor to receive a first detecting signal, and generates the control signal according to the first detecting signal. When the SR controller detects that the SR circuit is abnormal, the SR controller generates the controller signal to keep the SR transistor at an on state so as to perform an abnormal protection on the SR circuit.

公开(公告)号：US09973087B1

公开(公告)日：2018-05-15

申请号：US15384322

申请日：2016-12-20

Applicant: Power Forest Technology Corporation

Inventor： Pao-Chuan Lin

IPC: H02M3/158 ,  H02M1/096 ,  H02M1/32 ,  H02M1/00

CPC classification number: H02M1/096 ,  G05F1/46 ,  H02M3/156 ,  H02M3/1588 ,  H02M2001/0009

Abstract: A power conversion apparatus is provided. A detecting circuit detects a current flowing into a boot voltage input pin and converts the current into a corresponding detecting voltage. An adjusting signal generating circuit generates an adjusting signal according to the detecting voltage. A control circuit adjusts control parameters thereof according to the adjusting signal.

公开(公告)号：US09742295B2

公开(公告)日：2017-08-22

申请号：US14884784

申请日：2015-10-16

Applicant: Power Forest Technology Corporation

Inventor： Chun-Teh Chen

IPC: H02M3/335 ,  H02M1/00

CPC classification number: H02M3/33523 ,  H02M2001/0009

Abstract: A power conversion apparatus including a flyback power conversion circuit, a control chip and a detection auxiliary circuit is provided. The flyback power conversion circuit converts an input voltage into a direct current (DC) output voltage. The control chip generates a pulse width modulation (PWM) signal for controlling operations of the flyback power conversion circuit. The detection auxiliary circuit assists the control chip in obtaining a first detection voltage via a multi-function detection pin of the control chip within an enabling period of the PWM signal, so as to execute an over current detection according to the first detection voltage. Besides, the detection auxiliary circuit assists the control chip in obtaining a second detection voltage via the multi-function detection pin within a disabling period of the PWM signal, so as to execute a valley voltage detection according to the second detection voltage.

公开(公告)号：US09735693B2

公开(公告)日：2017-08-15

申请号：US14689041

申请日：2015-04-16

Applicant: Power Forest Technology Corporation

Inventor： Chein-Kuo Shein

IPC: H02M3/335 ,  H02M1/00

CPC classification number: H02M3/33592 ,  H02M2001/0032 ,  H02M2001/0054 ,  Y02B70/1475 ,  Y02B70/1491 ,  Y02B70/16

Abstract: A power conversion apparatus is provided. The power conversion apparatus includes a transformer, a synchronous rectification (SR) transistor and an SR control circuit. A first terminal of a primary side of the transformer receives an input voltage. A first terminal of a secondary side of the transformer provides an output voltage to a load. A first drain/source terminal of the SR transistor is coupled to a second terminal of the secondary side of the transformer. A second drain/source terminal of the SR transistor is coupled to a first ground terminal. A gate terminal of the SR transistor receives a control signal. The SR control circuit receives a signal of the first drain/source terminal of the SR transistor to determine statuses of the load and generate the control signal. When the load is a light load, the SR control circuit enters a power-saving mode and turns off the SR transistor.

公开(公告)号：US09479069B2

公开(公告)日：2016-10-25

申请号：US14274780

申请日：2014-05-12

Applicant: Power Forest Technology Corporation

Inventor： Tso-Min Chen

IPC: H02M1/32 ,  H02M3/335

CPC classification number: H02M3/33523 ,  H02M1/32 ,  H02M2001/327

Abstract: A power conversion apparatus including a flyback power conversion circuit, a control chip and a detection auxiliary circuit is provided. The flyback power conversion circuit receives and converts an AC input voltage into a DC output voltage. The control chip generates a PWM signal in response to a power supply requirement to control operations of the flyback power conversion circuit, and the control chip has a multi-function detection pin. The detection auxiliary circuit assists the control chip to obtain an auxiliary voltage related to the DC output voltage via the multi-function detection pin, and thereby determines a transition time of the PWM signal according to the auxiliary voltage. Besides, the detection auxiliary circuit assists the control chip to execute detections of an over temperature protection (OTP) and an over voltage protection (OVP) via the multi-function detection pin respectively within first and second detection phases.

Abstract translation: 提供一种包括反激式电力转换电路，控制芯片和检测辅助电路的电力转换装置。 回扫电力转换电路接收并将AC输入电压转换为DC输出电压。 控制芯片根据用于控制反激式功率转换电路的动作的电源要求生成PWM信号，控制芯片具有多功能检测引脚。 检测辅助电路通过多功能检测引脚帮助控制芯片获得与直流输出电压相关的辅助电压，从而根据辅助电压确定PWM信号的转换时间。 此外，检测辅助电路有助于控制芯片分别在第一和第二检测阶段通过多功能检测引脚执行过温保护（OTP）和过压保护（OVP）的检测。

公开(公告)号：US20160149480A1

公开(公告)日：2016-05-26

申请号：US14887616

申请日：2015-10-20

Applicant: Power Forest Technology Corporation

Inventor： Ren-Huei TZENG ,  Kuan-Sheng WANG ,  Hsien-Yuan CHIANG

IPC: H02M1/32 ,  H02M3/335

CPC classification number: H02M1/32 ,  H02M3/33523

Abstract: A power supply with low voltage protection provides an output voltage. The power supply includes a driving switch and a control unit. The control unit generates a control signal with a duty cycle. The driving switch receives the control signal to drive the output voltage of the power supply. The control unit enables an under-voltage protection mode when the control unit detects that the output voltage is less than a threshold output voltage value and the duty cycle is less than a maximum duty cycle value. The control unit disables the under-voltage protection mode when the control unit detects that the output voltage is less than the threshold output voltage value and the duty cycle reaches to the maximum duty cycle value.

Abstract translation: 具有低电压保护功能的电源提供输出电压。 电源包括驱动开关和控制单元。 控制单元产生占空比的控制信号。 驱动开关接收控制信号以驱动电源的输出电压。 当控制单元检测到输出电压小于阈值输出电压值并且占空比小于最大占空比值时，控制单元启用欠压保护模式。 当控制单元检测到输出电压小于阈值输出电压值且占空比达到最大占空比值时，控制单元禁用欠压保护模式。