Patents by Inventor Huang Zhang Xu

Huang Zhang Xu 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).

  • Applying charge pump to realize frequency jitter for switched mode power controller
    Patent number: 8093955
    Abstract: Method and apparatus for adding jitter to an oscillator for reducing EMI are disclosed An oscillator circuit includes an oscillator configured to generate a first clock having a first frequency and a frequency jitter circuit including a charge pump configured to charge and discharge first and second capacitors repeatedly for obtaining a time-varying voltage having a second frequency. The time-varying voltage is coupled to the oscillator to vary the first frequency within a frequency range. The charge pump includes a first switch for coupling the first capacitor to a voltage source and a second switch for coupling the first capacitor to the second capacitor. A charge transfer between the first and second capacitors is configured to provide the time-varying voltage.
    Type: Grant
    Filed: August 26, 2009
    Date of Patent: January 10, 2012
    Assignee: BCD Semiconductor Manufacturing Limited
    Inventors: Zheng Ying, Huang Zhang Xu
  • Applying Charge Pump To Realize Frequency Jitter For Switched Mode Power Controller
    Publication number: 20100246219
    Abstract: Method and apparatus for adding jitter to an oscillator for reducing EMI are disclosed An oscillator circuit includes an oscillator configured to generate a first clock having a first frequency and a frequency jitter circuit including a charge pump configured to charge and discharge first and second capacitors repeatedly for obtaining a time-varying voltage having a second frequency. The time-varying voltage is coupled to the oscillator to vary the first frequency within a frequency range. The charge pump includes a first switch for coupling the first capacitor to a voltage source and a second switch for coupling the first capacitor to the second capacitor. A charge transfer between the first and second capacitors is configured to provide the time-varying voltage.
    Type: Application
    Filed: August 26, 2009
    Publication date: September 30, 2010
    Applicant: BCD Semiconductor Manufacturing Limited
    Inventors: Zheng Ying, Huang Zhang Xu