Patent ID: 8737012
Filing Date: 2014-05-27
Classification: G11B

Abstract:
1. An apparatus for use with a hard disk drive, comprising: a selectable notch filter with a selectable notch frequency; a shock sensor of the hard disk drive, coupled to the selectable notch filter, the shock sensor having at least one resonance frequency; a flip flop coupled to an output of the notch filter and an output of the shock sensor; and a calibration logic coupled to an output of the flip flop, wherein an output of the calibration logic is coupled to a selection input of the selectable notch filter, wherein the selectable notch filter is programmed by the calibration logic to have a notch frequency that substantially cancels the at least one resonance frequency of the shock sensor of the hard drive, wherein an output phase of the selectable notch filter is compared to an input phase of the input notch filter to determine the at least one resonant frequency of the selectable notch filter to be cancelled.