Patents by Inventor Wenduo Liu

Wenduo Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11955895
    Abstract: A flyback converter control architecture is provided in which primary-only feedback techniques are used to ensure smooth startup and detection of fault conditions. During steady-state operation, secondary-side regulation is employed. In addition, current limits are monitored during steady-state operation using primary-only feedback techniques to obviate the need for a secondary-side current sense resistor.
    Type: Grant
    Filed: January 18, 2022
    Date of Patent: April 9, 2024
    Assignee: DIALOG SEMICONDUCTOR INC.
    Inventors: Yong Li, Cong Zheng, Xiaoyan Wang, Wenduo Liu
  • Publication number: 20230231468
    Abstract: A failure detection circuit for a power switch transistor in a power switching converter is provided that compares a drive voltage for driving a gate of the power switch transistor to a plurality of thresholds. Based upon when the drive voltage crosses each threshold in the plurality of thresholds, a logic circuit determines whether a fault condition exists for the power switch transistor.
    Type: Application
    Filed: January 19, 2022
    Publication date: July 20, 2023
    Inventor: Wenduo LIU
  • Patent number: 11689095
    Abstract: A gate drive control circuit is provided that charges a gate voltage of a power switch transistor during a power switch transistor on-time period. During a first portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-low resistance. During a second portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-high resistance. Finally, during a third portion of the on-time period, the gate drive control circuit charges the gate voltage through another relatively-low resistance.
    Type: Grant
    Filed: January 8, 2021
    Date of Patent: June 27, 2023
    Assignee: Dialog Semiconductor Inc.
    Inventors: Wenduo Liu, Huangxuan Gong, Vijay Kanagala, Hien Bui
  • Patent number: 11626803
    Abstract: A switching power converter is provided that adaptively changes the on-time period for an auxiliary switch transistor to locate a boundary between sufficient and insufficient energy.
    Type: Grant
    Filed: January 6, 2020
    Date of Patent: April 11, 2023
    Assignee: Dialog Semiconductor Inc.
    Inventors: Wenduo Liu, Cong Zheng, Xiaoyan Wang, Pengju Kong
  • Patent number: 11588409
    Abstract: A flyback converter communication channel is provided that comprises a pair of capacitors. A transmitter on a first side of a transformer for the flyback converter transmits a transmitter signal over a first one of the capacitors. The transmitter also transmits a complement of the transmitter signal over a second one of the capacitors. A receiver on a second side of the transformer controls a switch transistor responsive to a high-pass-filtered difference of the received signals from the pair of capacitors.
    Type: Grant
    Filed: October 6, 2020
    Date of Patent: February 21, 2023
    Assignee: Dialog Semiconductor Inc.
    Inventors: Wenduo Liu, Kun Yang, Laiqing Ping
  • Patent number: 11532991
    Abstract: An auxiliary winding for a flyback converter includes a floating terminal coupled to ground through a diode. A primary-side controller has a power supply voltage terminal coupled to a remaining terminal of the auxiliary winding and has a voltage sense terminal coupled to the floating terminal.
    Type: Grant
    Filed: January 5, 2021
    Date of Patent: December 20, 2022
    Assignee: Dialog Semiconductor Inc.
    Inventors: Wenduo Liu, Heng Yun
  • Patent number: 11527962
    Abstract: A standby power system for a flyback converter is disclosed. The flyback converter includes a primary-side, a secondary-side, an output terminal at the secondary-side, and a secondary-side controller, where the output terminal is configured to electrically connect to a load. The standby power system comprises a comparator at the secondary-side, an opto-coupler in signal communication with the primary-side, the secondary-side, and the comparator, and a cable detach detector (or load detector). The cable detach detector is configured to determine whether a device is electrically connected to the flyback converter through a charging cable and to set the flyback converter into a standby mode if the deice is disconnected from the charging cable.
    Type: Grant
    Filed: September 14, 2020
    Date of Patent: December 13, 2022
    Assignee: Dialog Semiconductor Inc.
    Inventors: Pengju Kong, Wenduo Liu, Yong Xiong Lin
  • Patent number: 11437916
    Abstract: A flyback converter is disclosed that includes an auxiliary switch controller that adaptively controls the auxiliary switch for improved zero voltage switching. The auxiliary switch control adaptively adjusts the auxiliary switch on-time period responsive to a transformer reset time for the flyback converter, a resonant oscillation period for a power switch terminal voltage for a power switch transistor, and an on-time period for the power switch transistor to provide the improved zero voltage switching.
    Type: Grant
    Filed: June 16, 2020
    Date of Patent: September 6, 2022
    Assignee: Dialog Semiconductor Inc.
    Inventors: Cong Zheng, Wenduo Liu, Jianming Yao
  • Publication number: 20220224217
    Abstract: A gate drive control circuit is provided that charges a gate voltage of a power switch transistor during a power switch transistor on-time period. During a first portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-low resistance. During a second portion of the on-time period, the gate drive control circuit charges the gate voltage through a relatively-high resistance. Finally, during a third portion of the on-time period, the gate drive control circuit charges the gate voltage through another relatively-low resistance.
    Type: Application
    Filed: January 8, 2021
    Publication date: July 14, 2022
    Inventors: Wenduo LIU, Huangxuan GONG, Vijay KANAGALA, Hien BUI
  • Publication number: 20220216798
    Abstract: An auxiliary winding for a flyback converter includes a floating terminal coupled to ground through a diode. A primary-side controller has a power supply voltage terminal coupled to a remaining terminal of the auxiliary winding and has a voltage sense terminal coupled to the floating terminal.
    Type: Application
    Filed: January 5, 2021
    Publication date: July 7, 2022
    Inventors: Wenduo LIU, Heng YUN
  • Publication number: 20220140735
    Abstract: A flyback converter control architecture is provided in which primary-only feedback techniques are used to ensure smooth startup and detection of fault conditions. During steady-state operation, secondary-side regulation is employed. In addition, current limits are monitored during steady-state operation using primary-only feedback techniques to obviate the need for a secondary-side current sense resistor.
    Type: Application
    Filed: January 18, 2022
    Publication date: May 5, 2022
    Inventors: Yong Li, Cong ZHENG, Xiaoyan WANG, Wenduo LIU
  • Publication number: 20220085726
    Abstract: A standby power system for a flyback converter is disclosed. The flyback converter includes a primary-side, a secondary-side, an output terminal at the secondary-side, and a secondary-side controller, where the output terminal is configured to electrically connect to a load. The standby power system comprises a comparator at the secondary-side, an opto-coupler in signal communication with the primary-side, the secondary-side, and the comparator, and a cable detach detector (or load detector). The cable detach detector is configured to determine whether a device is electrically connected to the flyback converter through a charging cable and to set the flyback converter into a standby mode if the deice is disconnected from the charging cable.
    Type: Application
    Filed: September 14, 2020
    Publication date: March 17, 2022
    Inventors: Pengju KONG, Wenduo LIU, Yong Xiong LIN
  • Patent number: 11234318
    Abstract: A DALI interface is provided that includes a digital isolator having an input terminal and an output terminal. A DALI bus controlled by a master device controls a binary voltage state of a voltage rail. A DFET couples between the input terminal and the output terminal to control a voltage of the input terminal responsive to the control of the DALI bus by the master device. The digital isolator responds to the control of the input terminal voltage to drive a digital signal through an isolation barrier to control a voltage of the output terminal to control a slave lighting device.
    Type: Grant
    Filed: May 21, 2020
    Date of Patent: January 25, 2022
    Assignee: DIALOG SEMICONDUCTOR INC.
    Inventors: Wenduo Liu, Kun Yang
  • Patent number: 11223283
    Abstract: Disclosed is a universal primary-only output current regulation for a flyback converter. A controller determines a peak sense resistor voltage responsive to a desired average output current for the flyback converter during a continuous conduction mode of operation. After a power switch transistor is cycled on, the controller monitors a sense resistor voltage to determine when the sense resistor voltage equals the peak sense resistor voltage. The controller switches off the power switch transistor when the sense resistor voltage equals the peak sense resistor voltage to maintain an average output current for the flyback converter equal to the desired average output current.
    Type: Grant
    Filed: April 20, 2020
    Date of Patent: January 11, 2022
    Assignee: Dialog Semiconductor Inc.
    Inventors: Cong Zheng, Wenduo Liu, Hien Bui
  • Publication number: 20210328517
    Abstract: Disclosed is a universal primary-only output current regulation for a flyback converter. A controller determines a peak sense resistor voltage responsive to a desired average output current for the flyback converter during a continuous conduction mode of operation. After a power switch transistor is cycled on, the controller monitors a sense resistor voltage to determine when the sense resistor voltage equals the peak sense resistor voltage. The controller switches off the power switch transistor when the sense resistor voltage equals the peak sense resistor voltage to maintain an average output current for the flyback converter equal to the desired average output current.
    Type: Application
    Filed: April 20, 2020
    Publication date: October 21, 2021
    Inventors: Cong ZHENG, Wenduo LIU, Hien BUI
  • Patent number: 11139745
    Abstract: A flyback converter is disclosed that times a detection time for each cycle of a power switch transistor. The detection time ends when a sense resistor voltage exceeds a threshold voltage. Over a half cycle of an AC input voltage to the flyback converter measures a series of detection time and determines a minimum detection time from the series of detection times. If the minimum detection time exceeds a brownout delay, a brownout condition exists. If the minimum detection time is less than an overvoltage delay, an overvoltage condition exists.
    Type: Grant
    Filed: June 24, 2020
    Date of Patent: October 5, 2021
    Assignee: DIALOG SEMICONDUCTOR INC.
    Inventors: Jianming Yao, Mengfei Liu, Wenduo Liu
  • Publication number: 20210083586
    Abstract: A flyback converter control architecture is provided in which primary-only feedback techniques are used to ensure smooth startup and detection of fault conditions. During steady-state operation, secondary-side regulation is employed. In addition, current limits are monitored during steady-state operation using primary-only feedback techniques to obviate the need for a secondary-side current sense resistor.
    Type: Application
    Filed: December 1, 2020
    Publication date: March 18, 2021
    Inventors: Yong LI, Cong ZHENG, Xiaoyan WANG, Wenduo LIU
  • Publication number: 20210021201
    Abstract: A flyback converter communication channel is provided that comprises a pair of capacitors. A transmitter on a first side of a transformer for the flyback converter transmits a transmitter signal over a first one of the capacitors. The transmitter also transmits a complement of the transmitter signal over a second one of the capacitors. A receiver on a second side of the transformer controls a switch transistor responsive to a high-pass-filtered difference of the received signals from the pair of capacitors.
    Type: Application
    Filed: October 6, 2020
    Publication date: January 21, 2021
    Inventors: Wenduo LIU, Kun YANG, Laiqing PING
  • Publication number: 20200412267
    Abstract: A flyback converter is disclosed that times a detection time for each cycle of a power switch transistor. The detection time ends when a sense resistor voltage exceeds a threshold voltage. Over a half cycle of an AC input voltage to the flyback converter measures a series of detection time and determines a minimum detection time from the series of detection times. If the minimum detection time exceeds a brownout delay, a brownout condition exists. If the minimum detection time is less than an overvoltage delay, an overvoltage condition exists.
    Type: Application
    Filed: June 24, 2020
    Publication date: December 31, 2020
    Inventors: Jianming YAO, Mengfei LIU, Wenduo LIU
  • Publication number: 20200403521
    Abstract: A flyback converter is disclosed that includes an auxiliary switch controller that adaptively controls the auxiliary switch for improved zero voltage switching.
    Type: Application
    Filed: June 16, 2020
    Publication date: December 24, 2020
    Inventors: Cong ZHENG, Wenduo LIU, Jianming YAO