Patents by Inventor Nang-Ching Yeung

Nang-Ching Yeung 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).

  • Avoid audio noise of a LED driver during PWM dimming
    Patent number: 9049766
    Abstract: A LED driver using a PWM signal for dimming control includes a power converter and a current regulator. The power converter provides an output voltage and a load current for a plurality of LEDs. The current regulator provides a load current dependent signal for the power converter to speed up load transient response caused by variation of the load current, to reduce the ripple of the output voltage, and thereby to avoid audio noise during PWM dimming.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: June 2, 2015
    Assignee: RICHTEK TECHNOLOGY CORP.
    Inventors: Tsung-Wei Huang, Shui-Mu Lin, Huan-Chien Yang, Nang-Ching Yeung, Ti-Ti Liu
  • AVOID AUDIO NOISE OF A LED DRIVER DURING PWM DIMMING
    Publication number: 20130342124
    Abstract: A LED driver using a PWM signal for dimming control includes a power converter and a current regulator. The power converter provides an output voltage and a load current for a plurality of LEDs. The current regulator provides a load current dependent signal for the power converter to speed up load transient response caused by variation of the load current, to reduce the ripple of the output voltage, and thereby to avoid audio noise during PWM dimming.
    Type: Application
    Filed: June 19, 2013
    Publication date: December 26, 2013
    Inventors: Tsung-Wei HUANG, Shui-Mu LIN, Huan-Chien YANG, Nang-Ching YEUNG, Ti-Ti LIU
  • Circuit and method for controlling light emitting device, and integrated circuit therefor
    Patent number: 8405320
    Abstract: The present invention provides a transistor switch on a light emitting device channel, the transistor switch receiving a control voltage VG. A current source circuit controls the current on the light emitting device channel, the current source circuit requiring a minimum voltage VR for normal operation. The present invention further provides a dynamic headroom controller circuit which compares a voltage VS at a current outflow end of the transistor switch with the voltage VR to determine the relationship between the voltage VS and the voltage VR when the control voltage VG is higher than a reference voltage VH, and adjusts the voltage difference between the voltage VS and the voltage VR accordingly.
    Type: Grant
    Filed: March 27, 2011
    Date of Patent: March 26, 2013
    Assignee: Richtek Technology Corporation
    Inventors: Tsung-Wei Huang, Shui-Mu Lin, Nang-Ching Yeung, Ti-Ti Liu, Huan-Chien Yang
  • Circuit and Method for Controlling Light Emitting Device, and Integrated Circuit Therefor
    Publication number: 20110169423
    Abstract: The present invention provides a transistor switch on a light emitting device channel, the transistor switch receiving a control voltage VG. A current source circuit controls the current on the light emitting device channel, the current source circuit requiring a minimum voltage VR for normal operation. The present invention further provides a dynamic headroom controller circuit which compares a voltage VS at a current outflow end of the transistor switch with the voltage VR to determine the relationship between the voltage VS and the voltage VR when the control voltage VG is higher than a reference voltage VH, and adjusts the voltage difference between the voltage VS and the voltage VR accordingly.
    Type: Application
    Filed: March 27, 2011
    Publication date: July 14, 2011
    Inventors: Tsung-Wei Huang, Shui-Mu Lin, Nang-Ching Yeung, Ti-Ti Liu, Huan-Chien Yang