Patents by Inventor Jeffrey A. Gleason

Jeffrey A. Gleason 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).

  • Method and apparatus for measuring resistance of a resistive sensor
    Publication number: 20080062551
    Abstract: An apparatus and method for determining a head parameter value (e.g., head resistance) of a resistive head. A test head current is supplied to the head during a head parameter measurement interval using the same current sources that supply a bias current to the head during an operating (read operation) interval. The determined head parameter value is latched for use in setting the control loop gain for a control loop that controls the current sources during the operating interval.
    Type: Application
    Filed: September 13, 2006
    Publication date: March 13, 2008
    Inventors: Daniel J. Dolan, Hao Fang, Jeffrey A. Gleason, Ross S. Wilson
  • Integrated bias and offset recovery amplifier
    Patent number: 7339760
    Abstract: A preamplifier circuit is connected to a transducing head, and has integrated bias circuitry and offset recovery circuitry. The offset recovery circuitry is activated in response to a transition from write mode to read more to provide an output signal representative of a signal across the transducing head. The bias circuitry is driven by the output signal of the offset recovery circuitry to bias the transducing head.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: March 4, 2008
    Assignee: Agere Systems Inc.
    Inventors: Jeffrey A. Gleason, John D. Leighton, Scott M. O'Brien
  • 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