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:
Oct. 20, 1992
Filed:
Aug. 06, 1991
Applicant:
Inventors:
Jefferey A Gleason, Minneapolis, MN (US);
David E Sutliff, Eagan, MN (US);
Assignee:
VTC Inc., Bloomington, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G11B / ; G11B / ;
U.S. Cl.
CPC ...
360 46 ; 360 65 ; 360 67 ;
Abstract
A variable bandwidth differentiating amplifier comprises a differential amplifier and a variable filter comprising a capacitor and a pair of diodes. A current source, having a current value derived from the track postion information in the track count register of a disk drive forward biases the diodes to alter the frequency response of the filter. A Gilbert multiplier may also be included to maintain a constant voltage gain for the differential amplifier.