Yoo S Kim

US Patent:

6525892, Feb 25, 2003

Filed:

Jan 28, 2000

Appl. No.:

09/493751

Inventors:

Gary L. Dunbar - Gilroy CA
Yoo H. Kim - Laguna Niguel CA
Hanan Kupferman - Diamond Bar CA
Brian Tanner - San Jose CA
David P. Turner - Los Gatos CA

Assignee:

Western Digital Technologies, Inc. - Lake Forest CA

International Classification:

G11B 2736

US Classification:

360 31, 360 46, 360 68, 360 75

Abstract:

A method of calibrating a write current-setting for writing servo sectors onto a recording surface through a head in a head disk assembly of a disk drive is disclosed. A preamplifier circuit has an input for receiving a selected control signal set by a current-setting value, the preamplifier circuit causing current to flow through the head with a current magnitude determined by the current-setting value. A multiple-pass process is performed in which a series of current-setting values are set for the control signal for generating a plurality of quality metrics each indicative of a quality of the selected control signal. Each pass in the multiple-pass process includes the steps of providing a data sequence to the preamplifier circuit to cause a test pattern to be written to the recording surface, and reading the test pattern and generating and storing at least one of the plurality of quality metrics. The generated and stored quality metrics are then evaluated to select a current-setting value for the selected control signal. The selected current-setting value is then set for the head, and the servo sectors are written onto the recording surface through the head.