Patents by Inventor Tsung-Kai Kao

Tsung-Kai Kao 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: 10483947
    Abstract: The invention provides an anti-aliasing filter (AAF) for discretization at a sampling period. The AAF may include an operational amplifier having an input terminal and an output terminal, a first capacitor coupled between the input terminal and the output terminal, a second capacitor, and a first switch coupled between the first capacitor and the second capacitor. During a first phase, the first switch may conduct the second capacitor to the first capacitor. During a second phase, the first switch may stop conducting the second capacitor to the first capacitor. The first phase may last for one said sampling period.
    Type: Grant
    Filed: October 11, 2018
    Date of Patent: November 19, 2019
    Assignee: MEDIATEK INC.
    Inventors: Tien-Yu Lo, Chan-Hsiang Weng, Patrick Cooney, Tsung-Kai Kao, Stacy Ho
  • Publication number: 20190288672
    Abstract: The invention provides an anti-aliasing filter (AAF) for discretization at a sampling period. The AAF may include an operational amplifier having an input terminal and an output terminal, a first capacitor coupled between the input terminal and the output terminal, a second capacitor, and a first switch coupled between the first capacitor and the second capacitor. During a first phase, the first switch may conduct the second capacitor to the first capacitor. During a second phase, the first switch may stop conducting the second capacitor to the first capacitor. The first phase may last for one said sampling period.
    Type: Application
    Filed: October 11, 2018
    Publication date: September 19, 2019
    Inventors: Tien-Yu LO, Chan-Hsiang WENG, Patrick Cooney, Tsung-Kai KAO, Stacy HO
  • Patent number: 9853653
    Abstract: Apparatus and methods for reducing noise and distortion in current digital-to-analog converters (IDACs). Compensating capacitors may be connected to current sources in an IDAC. The compensating capacitors may be driven with signals 5 derived from the output of the IDAC to cancel transient current spikes that would otherwise occur on the output of the IDAC.
    Type: Grant
    Filed: September 8, 2016
    Date of Patent: December 26, 2017
    Assignee: MediaTek Inc.
    Inventor: Tsung-Kai Kao
  • Publication number: 20170077936
    Abstract: Apparatus and methods for reducing noise and distortion in current digital-to-analog converters (IDACs) are described. Compensating capacitors may be connected to current sources in an IDAC. The compensating capacitors may be driven with signals derived from the output of the IDAC to cancel transient current spikes that would otherwise occur on the output of the IDAC.
    Type: Application
    Filed: September 8, 2016
    Publication date: March 16, 2017
    Applicant: MediaTek Inc.
    Inventor: Tsung-Kai Kao
  • Patent number: 9350373
    Abstract: An analog-to-digital conversion that converts an input signal to an output signal by using multiple analog-to-digital converting circuits. A first analog-to-digital converting circuit generates a first signal based on the input signal and further outputs a feature signal of a first quantization error of the first analog-to-digital converting circuit. A second analog-to-digital converting circuit generates a second signal based on the input signal and the feature signal. The output combiner combines the first signal and the second signal to generate the output signal and thereby to reduce a quantization error factor in the output signal that is due to the first quantization error.
    Type: Grant
    Filed: June 17, 2015
    Date of Patent: May 24, 2016
    Assignee: MEDIATEK INC.
    Inventor: Tsung-Kai Kao
  • Publication number: 20150131811
    Abstract: A signal output device includes: a control circuit for receiving at least a first input control signal and outputting an output control signal according to at least the first input control signal, wherein the first input control signal has a first signal segment followed by a second signal segment, and a voltage level of the first signal segment is unknown; and a driver circuit, operated according to a supply power, for receiving the output control signal from the control circuit; wherein a voltage of the supply power is settle before the second signal segment of the first input control signal is received by the control circuit; when the supply power is turned on, the driver circuit operates under a specific power state; and when the second signal segment of the first input control signal is received by the control circuit, the driver circuit keeps operating under the specific power state.
    Type: Application
    Filed: January 21, 2015
    Publication date: May 14, 2015
    Inventors: Tsung-Kai Kao, Pao-Cheng Chiu, Chien-Ming Chen
  • Patent number: 8653869
    Abstract: A Fractional-N PLL includes a phase frequency detector module receiving a first clock and a second clock that is associated with a feedback path arrangement. A coarse phase adjustment module receives a coarse phase component and an output signal associated with a divider module used in the feedback path arrangement and performs a coarse phase adjustment. A fine phase adjustment module performs fine phase adjustment using a fine phase component and the coarse phase adjustment as input to produce the second clock. The fine phase adjustment module nominally cancels most or all of the quantization noise present during the coarse phase adjustment, thereby greatly reducing the net phase noise of the divider module. A segmentation module receives a control signal and generates the coarse phase component and the fine phase component that are provided to the fine phase adjustment module and the coarse phase adjustment module for processing.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: February 18, 2014
    Assignee: Media Tek Singapore Pte. Ltd.
    Inventors: Tsung-Kai Kao, Che-Fu Liang, Michael A. Ashburn, Jr.
  • Publication number: 20130099839
    Abstract: A Fractional-N PLL includes a phase frequency detector module receiving a first clock and a second clock that is associated with a feedback path arrangement. A coarse phase adjustment module receives a coarse phase component and an output signal associated with a divider module used in the feedback path arrangement and performs a coarse phase adjustment. A fine phase adjustment module performs fine phase adjustment using a fine phase component and the coarse phase adjustment as input to produce the second clock. The fine phase adjustment module nominally cancels most or all of the quantization noise present during the coarse phase adjustment, thereby greatly reducing the net phase noise of the divider module. A segmentation module receives a control signal and generates the coarse phase component and the fine phase component that are provided to the fine phase adjustment module and the coarse phase adjustment module for processing.
    Type: Application
    Filed: September 13, 2012
    Publication date: April 25, 2013
    Inventors: Tsung-Kai Kao, Che-Fu Liang, Michael A. Ashburn, JR.
  • Publication number: 20110116652
    Abstract: A signal output device includes: a control circuit for receiving at least a first input control signal and outputting an output control signal according to at least the first input control signal, wherein the first input control signal comprises a first signal segment followed by a second signal segment; and a driver circuit, operated according to a supply power, for receiving the output control signal from the control circuit and selectively generating an output signal according to the output control signal; wherein the supply power is turned on before the second signal segment of the first input control signal is received by the control circuit; when the supply power is turned on, the driver circuit operates under a specific power state; and when the second signal segment of the first input control signal is received by the control circuit, the driver circuit keeps operating under the specific power state.
    Type: Application
    Filed: November 19, 2009
    Publication date: May 19, 2011
    Inventors: Tsung-Kai Kao, Pao-Cheng Chiu, Chien-Ming Chen
  • Publication number: 20090322938
    Abstract: A signal processing apparatus for generating an output analog signal according to a raw digital signal is disclosed. The signal processing apparatus includes a DAC, a storage device, and an adjusting device. The storage device is utilized for storing a target mapping table equivalent to a combination of a predetermined correction mapping table and a DAC calibration mapping table corresponding to the DAC. The adjusting device is coupled to the DAC and the storage device, and is utilized for adjusting the raw digital signal to generate a calibrated digital signal according to the target mapping table stored in the storage device. The DAC converts the calibrated digital signal to generate the output analog signal.
    Type: Application
    Filed: June 27, 2008
    Publication date: December 31, 2009
    Inventors: Yang-Hung Shih, Tang-Hung Po, Tsung-Kai Kao, Shang-Yi Lin