Patents by Inventor Yun-Hak Koh

Yun-Hak Koh 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: 10171711
    Abstract: A transmitter circuit coupled to output image data from an image sensor includes a plurality of transmitters. The transmitters may include a plurality of drivers coupled to receive a data signal, and output a differential signal in response to receiving the data signal. A de-emphasis circuit is coupled between a first output of a first driver in the plurality of drivers, and a second output of a second driver in the plurality of drivers. The de-emphasis circuit is coupled to receive a de-emphasis control signal, and in response to receiving the de-emphasis control signal, the de-emphasis circuit reduces a magnitude of the differential signal.
    Type: Grant
    Filed: January 16, 2018
    Date of Patent: January 1, 2019
    Assignee: OmniVision Technologies, Inc.
    Inventors: Min Liu, Yun Hak Koh, Charles Wu
  • Patent number: 9762833
    Abstract: Techniques and methods for reducing or preventing latch up in row decoder circuits are disclosed herein. An example apparatus may include an array of pixels, a row address decoder, and control circuitry. The row decode circuit including a plurality of decode circuits, each including at least two transistors having respective body terminals coupled to a first node. The control circuitry including a body biasing circuit coupled to the first node, the body biasing circuit to adaptively provide a bias voltage to the first node in response to an operating state of the imaging system and/or a change in one of two reference voltages based on a control signal provided by a bias control circuit.
    Type: Grant
    Filed: May 24, 2016
    Date of Patent: September 12, 2017
    Assignee: OmniVision Technologies, Inc.
    Inventors: Charles Qingle Wu, Yun Hak Koh
  • Patent number: 9608633
    Abstract: An interface circuit includes a pre-driver that converts the single-ended signal to an intermediate differential signal having a first voltage swing responsive to a first supply voltage supplied to the pre-driver. An output driver is coupled to receive the intermediate differential signal from the pre-driver to convert the intermediate differential signal to an output differential signal coupled to be received by a load coupled to the output driver. The output differential signal has a second voltage swing responsive to a second supply voltage supplied to the output driver. An internal regulator is coupled to receive a variable supply voltage to supply the second voltage to the output driver. The second supply voltage is generated in response to a bias signal. A replica bias circuit is coupled to receive the variable supply voltage to generate the bias signal.
    Type: Grant
    Filed: November 24, 2015
    Date of Patent: March 28, 2017
    Assignee: OmniVision Technologies, Inc.
    Inventors: Min Liu, Yun Hak Koh, Charles Qingle Wu
  • Patent number: 9300331
    Abstract: A transmitter for generating a differential signal pair including a pre-emphasis component. In an embodiment, the transmitter comprises pre-driver circuitry including an input to receive a single-ended data signal. The differential transmitter further comprises a load circuit coupled between the input and a node coupled to an output of the pre-driver circuitry which corresponds to a constituent signal of the differential signal pair. In another embodiment, the load circuit is configurable to provide a signal path between the input and the node. A configuration of the load circuit allows for a type of pre-emphasis to be included in the constituent signal.
    Type: Grant
    Filed: November 9, 2012
    Date of Patent: March 29, 2016
    Assignee: OmniVision Technologies, Inc.
    Inventors: Min Liu, Yun Hak Koh, Charles Qingle Wu
  • Publication number: 20140132592
    Abstract: A transmitter for generating a differential signal pair including a pre-emphasis component. In an embodiment, the transmitter comprises pre-driver circuitry including an input to receive a single-ended data signal. The differential transmitter further comprises a load circuit coupled between the input and a node coupled to an output of the pre-driver circuitry which corresponds to a constituent signal of the differential signal pair. In another embodiment, the load circuit is configurable to provide a signal path between the input and the node. A configuration of the load circuit allows for a type of pre-emphasis to be included in the constituent signal.
    Type: Application
    Filed: November 9, 2012
    Publication date: May 15, 2014
    Applicant: OmniVision Technologies, Inc.
    Inventors: Min Liu, Yun Hak Koh, Charles Qingle Wu
  • Patent number: 7868676
    Abstract: A driver circuit includes a pre-driver and an output driver. The pre-driver is coupled to receive an input signal and to generate first and second pre-driver output signals in response to the input signal. The output driver generates a driver output signal and includes first and second switches, a native mode transistor, and a driver output. The first switch has a first control terminal coupled to receive the first pre-driver output signal. The second switch has a second control terminal coupled to receive the second pre-driver output signal. The native mode transistor is coupled in series between the first switch and the second switch and has a third control terminal coupled to receive the voltage reference signal. The driver output is coupled between the native mode transistor and the second switch to output the driver output signal.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: January 11, 2011
    Assignee: OmniVision Technologies, Inc.
    Inventors: Yun-Hak Koh, Charles Qingle Wu
  • Publication number: 20100315053
    Abstract: A driver circuit includes a pre-driver and an output driver. The pre-driver is coupled to receive an input signal and to generate first and second pre-driver output signals in response to the input signal. The output driver generates a driver output signal and includes first and second switches, a native mode transistor, and a driver output. The first switch has a first control terminal coupled to receive the first pre-driver output signal. The second switch has a second control terminal coupled to receive the second pre-driver output signal. The native mode transistor is coupled in series between the first switch and the second switch and has a third control terminal coupled to receive the voltage reference signal. The driver output is coupled between the native mode transistor and the second switch to output the driver output signal.
    Type: Application
    Filed: August 20, 2010
    Publication date: December 16, 2010
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Yun-Hak Koh, Charles Qingle Wu
  • Patent number: 7804345
    Abstract: A driver circuit provides fast settling times, slew rate control, and power efficiency, while reducing the need for large external capacitors. A voltage reference circuit generates a voltage reference signal. A comparator compares the voltage reference signal and a driver output signal and generates an output high voltage control signal. An output driver includes a first and a second switch that are coupled together. The first and second switches are further coupled to generate the driver output signal in response to coupling the output high voltage control signal to the control terminal of the first switch and coupling an input signal to the control terminal of the second switch.
    Type: Grant
    Filed: January 15, 2008
    Date of Patent: September 28, 2010
    Assignee: OmniVision Technologies, Inc.
    Inventors: Yun-Hak Koh, Charles Qingle Wu
  • Patent number: 7619448
    Abstract: A transmitter provides fast settling times, slew rate control, and power efficiency while reducing the need for large external capacitors. The transmitter typically includes a pre-driver, driver, and replica circuit. The pre-driver can shift the voltage level of an input signal to produce a shifted signal. The pre-driver can shift the voltage level in response to a selectable load resistance circuit and a voltage regulation feedback signal. The driver receives the shifted signal and generates a driver output signal in response to the received shifted signal. The replica circuit can be a scaled replica of the pre-driver and the driver using scaled components from the pre-driver and driver circuits. The scaled components can be used to generate the voltage regulation feedback signal. The generated voltage regulation feedback signal represents, for example, whether the output voltage of the driver output is above a reference voltage.
    Type: Grant
    Filed: December 17, 2007
    Date of Patent: November 17, 2009
    Assignee: OmniVision Technologies, Inc.
    Inventors: Charles Qingle Wu, Yun-Hak Koh
  • Publication number: 20090180570
    Abstract: A driver circuit provides fast settling times, slew rate control, and power efficiency, while reducing the need for large external capacitors. A voltage reference circuit generates a voltage reference signal. A comparator compares the voltage reference signal and a driver output signal and generates an output high voltage control signal. An output driver includes a first and a second switch that are coupled together. The first and second switches are further coupled to generate the driver output signal in response to coupling the output high voltage control signal to the control terminal of the first switch and coupling an input signal to the control terminal of the second switch.
    Type: Application
    Filed: January 15, 2008
    Publication date: July 16, 2009
    Applicant: OMNIVISION TECHNOLOGIES, INC.
    Inventors: Yun-Hak Koh, Charles Qingle Wu
  • Publication number: 20090153219
    Abstract: A transmitter provides fast settling times, slew rate control, and power efficiency while reducing the need for large external capacitors. The transmitter typically includes a pre-driver, driver, and replica circuit. The pre-driver can shift the voltage level of an input signal to produce a shifted signal. The pre-driver can shift the voltage level in response to a selectable load resistance circuit and a voltage regulation feedback signal. The driver receives the shifted signal and generates a driver output signal in response to the received shifted signal. The replica circuit can be a scaled replica of the pre-driver and the driver using scaled components from the pre-driver and driver circuits. The scaled components can be used to generate the voltage regulation feedback signal. The generated voltage regulation feedback signal represents, for example, whether the output voltage of the driver output is above a reference voltage.
    Type: Application
    Filed: December 17, 2007
    Publication date: June 18, 2009
    Inventors: Charles Qingle Wu, Yun-Hak Koh