公开(公告)号：US20170163162A1

公开(公告)日：2017-06-08

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 ,  H03K17/785 ,  H02M1/08 ,  H03L7/00

CPC classification number: H02M3/33523 ,  H02M2001/0032 ,  Y02B70/16

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：US09614449B2

公开(公告)日：2017-04-04

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 ,  H02M1/00

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.

公开(公告)号：US10686366B2

公开(公告)日：2020-06-16

申请号：US16395341

申请日：2019-04-26

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Kuang-Fu Chang

IPC: H02M1/32 ,  H03K5/1254 ,  H03K5/24 ,  H02M3/335 ,  H02M1/00

Abstract: A flyback power converter includes: a transformer, a primary side switch and a primary side controller circuit. The primary side controller circuit includes: a pulse modulation circuit and a protection control circuit. The pulse modulation circuit generates a pulse modulation signal. The protection control circuit is coupled to the pulse modulation circuit and compares an AC voltage related signal with an over voltage threshold. When the AC voltage related signal exceeds the over voltage threshold, the comparison circuit generates an over voltage protection trigger signal. When the pulse number of the over voltage protection trigger signal exceeds the over voltage counting threshold, the over voltage counter circuit triggers an over voltage protection signal, to indicate that an over voltage condition occurs, and a protection operation is performed.

公开(公告)号：US20200014305A1

公开(公告)日：2020-01-09

申请号：US16395341

申请日：2019-04-26

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Kuang-Fu Chang

IPC: H02M3/335 ,  H02M1/32 ,  H03K5/24 ,  H03K5/1254 ,  H02H3/20

Abstract: A flyback power converter includes: a transformer, a primary side switch and a primary side controller circuit. The primary side controller circuit includes: a pulse modulation circuit and a protection control circuit. The pulse modulation circuit generates a pulse modulation signal. The protection control circuit is coupled to the pulse modulation circuit and compares an AC voltage related signal with an over voltage threshold. When the AC voltage related signal exceeds the over voltage threshold, the comparison circuit generates an over voltage protection trigger signal. When the pulse number of the over voltage protection trigger signal exceeds the over voltage counting threshold, the over voltage counter circuit triggers an over voltage protection signal, to indicate that an over voltage condition occurs, and a protection operation is performed.

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：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：US20180323717A1

公开(公告)日：2018-11-08

申请号：US15963058

申请日：2018-04-25

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Kuang-Fu Chang ,  Chien-Hung Chen

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

CPC classification number: H02M3/33515 ,  H02M1/08 ,  H02M1/32 ,  H02M1/36 ,  H02M2001/0025

Abstract: A flyback power converter circuit includes a transformer, a power switch, a primary side controller circuit, and a secondary side controller circuit. The transformer converts an input voltage to a first, a second and a third output voltages. The primary side controller circuit and the secondary side control are powered by the second voltage and a third voltage, respectively. In a burst mode, when the second output voltage is lower than a first threshold, a power regulation mode is triggered to control the power switch, such that the second output voltage is between the first threshold and a second threshold. After a predetermined delay time period, the power regulation mode stops and the flyback power converter circuit enters a reboot procedure, wherein the power switch is OFF such that the third voltage is lower than a secondary side reboot threshold, whereby the secondary side controller circuit is reboot.

公开(公告)号：US09853554B2

公开(公告)日：2017-12-26

申请号：US15153436

申请日：2016-05-12

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Kuang-Fu Chang

IPC: H02M3/335 ,  G06F1/26 ,  H02M1/00

CPC classification number: H02M3/33523 ,  G06F1/26 ,  G06F1/263 ,  G06F1/266 ,  G06F1/28 ,  H02M2001/0025 ,  H02M2001/0032 ,  Y02B70/16

Abstract: The present invention provides a power converter, and a control circuit and a standby power saving method thereof. The power converter provides an output voltage from an output terminal through an enable switch circuit to a power receiver. A detection signal shows whether a voltage at a signal transmission pin of the power converter is in a predetermined range, if not, the enable switch circuit is turned OFF. The power converter adjusts a feedback signal according to the detection signal or according to the detection signal and the output voltage, so as to adjust the output voltage to be lower than a normal operation level in a normal operation mode, to save power in a standby mode.

公开(公告)号：US11496055B2

公开(公告)日：2022-11-08

申请号：US16241964

申请日：2019-01-07

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：US10320304B2

公开(公告)日：2019-06-11

申请号：US15290771

申请日：2016-10-11

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Yu-Kai Chen ,  Kuang-Fu Chang

IPC: H02M3/335 ,  H02M1/08 ,  H02M1/32 ,  H02M1/00

Abstract: The present invention provides a power converter, a secondary side controller, and a short circuit determination method for a current sensing resistor of the power converter. The power converter is controlled by a power switch to convert an input voltage to an output voltage, and provide an output current to an output terminal. The power converter senses the output current by a current sensing resistor to generate first information which relates to the output current. The power converter generates second information according to an ON time, an OFF time or a switching period of the power switch, or according to an energy-releasing period for transmitting energy to the output terminal, wherein the second information indicates whether there is a substantial amount of energy transmitted to the output terminal. By checking whether the first information and the second information are contradictory to each other, a malfunction can be found.