Patents by Inventor Tommy Mao

Tommy Mao 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).

  • Substrate noise passive cancellation method for buck converter
    Patent number: 8179187
    Abstract: A method for passive cancellation of substrate noise for a buck converter uses an on-chip capacitor to reduce the substrate noise. The capacitor achieves a close-magnitude noise with opposite phase for better noise cancellation effect in the substrate. The capacitor can be realized as a MOS capacitor, NMOS isolation ring n-well capacitor, n-well junction capacitor, isolated p-well junction capacitor, etc. The capacitor is easy to implement. Further, bond wire parasitic inductance in the buck converter is used to reduce substrate noise.
    Type: Grant
    Filed: October 13, 2009
    Date of Patent: May 15, 2012
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Hongwei Zhao, Jian Yang, Iven Zheng, Tommy Mao, Waley Li
  • SUBSTRATE NOISE PASSIVE CANCELLATION METHOD FOR BUCK CONVERTER
    Publication number: 20100102875
    Abstract: A method for passive cancellation of substrate noise for a buck converter uses an on-chip capacitor to reduce the substrate noise. The capacitor achieves a close-magnitude noise with opposite phase for better noise cancellation effect in the substrate. The capacitor can be realized as a MOS capacitor, NMOS isolation ring n-well capacitor, n-well junction capacitor, isolated p-well junction capacitor, etc. The capacitor is easy to implement. Further, bond wire parasitic inductance in the buck converter is used to reduce substrate noise.
    Type: Application
    Filed: October 13, 2009
    Publication date: April 29, 2010
    Applicant: FREESCALE SEMICONDUCTOR, INC
    Inventors: Hongwei Zhao, Jian Yang, Iven Zheng, Tommy Mao, Waley Li