Patents by Inventor David E. Sutliff

David E. Sutliff 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).

  • Differentiating amplifier responsive to track locations and variations of element values from desired values
    Patent number: 5278700
    Abstract: An amplifier is compensated for variations in element values. A trim signal is generated based on element values of filter elements of a filter in the amplifier. An RC product in the amplifier is controlled based on the trim signal. The RC product corresponds to a product of a dynamic resistance value of a dynamic resistance element in the filter in the amplifier, and a capacitance value of capacitive elements in the filter. The RC product also determines a pole position of the amplifier. Gain in the amplifier is controlled based on the trim signal so that a desired gain is maintained.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: January 11, 1994
    Assignee: VTC Inc.
    Inventors: David E. Sutliff, Jeffrey A. Gleason
  • Method and apparatus for adjusting the pole positions of a differentiating amplifier
    Patent number: 5227737
    Abstract: An amplifier is compensated for variations in element values. A trim signal is generated based on element values of filter elements of a filter in the amplifier. An RC product in the amplifier is controlled based on the trim signal. The RC product corresponds to a product of a dynamic resistance value of a dynamic resistance element in the filter in the amplifier, and a capacitance value of capacitive elements in the filter. The RC product also determines a pole position of the amplifier. Gain in the amplifier is controlled based on the trim signal so that a desired gain is maintained.
    Type: Grant
    Filed: December 5, 1990
    Date of Patent: July 13, 1993
    Assignee: VTC Inc.
    Inventors: David E. Sutliff, Jeffrey A. Gleason
  • Adjustable bandwidth differentiating amplifier for a magnetic disk drive
    Patent number: 5157559
    Abstract: A variable bandwidth differentiating amplifier comprises a differential amplifier and a variable filter comprising a capacitor and a pair of diodes. A current source, having a current value derived from the track postion information in the track count register of a disk drive forward biases the diodes to alter the frequency response of the filter. A Gilbert multiplier may also be included to maintain a constant voltage gain for the differential amplifier.
    Type: Grant
    Filed: August 6, 1991
    Date of Patent: October 20, 1992
    Assignee: VTC Inc.
    Inventors: Jefferey A. Gleason, David E. Sutliff