Patents Assigned to Seagate Technoogy LLC
  • Method and apparatus for feedforward cancellation using a phase lock loop
    Patent number: 6628472
    Abstract: A method and apparatus are provided for generating a feedforward cancellation signal for a next sector of a disc in a disc drive. To form the cancellation signal, the method and apparatus generate a trigonometric value having the phase and frequency of a nonrepeatable runout error by passing a position error signal through a phase lock loop. An amplitude is determined for the cancellation signal based on the position error signal. The amplitude is then multiplied by the trigonometric value to from the cancellation signal.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: September 30, 2003
    Assignee: Seagate Technoogy LLC
    Inventor: Hai T. Ho