The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 01, 2010
Filed:
Jan. 21, 2009
William D. Huber, Hollister, CA (US);
William D. Huber, Hollister, CA (US);
Western Digital Technologies, Inc., Lake Forest, CA (US);
Abstract
A disk drive is disclosed comprising a disk, a head actuated over the disk, and control circuitry operable to estimate a fly height of the head by tuning a phase locked loop (PLL) in response to a fly height capacitance. In one embodiment, the PLL comprises a resistive component having a second terminal coupled to the fly height capacitance, a variable oscillator operable to generate a first oscillating signal applied to a first terminal of the resistive component to generate a second oscillating signal at the second end of the resistive component, and a phase detector operable to generate a control signal by comparing a phase of the first oscillating signal to a phase of the second oscillating signal. The control signal is applied to the variable oscillator to adjust a frequency of the first oscillating signal.