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:
Jan. 07, 1997
Filed:
Sep. 21, 1994
Vadim B Minuhin, Oklahoma City, OK (US);
Vladimir Kovner, Oklahoma City, OK (US);
Srinivasan Surendran, Norman, OK (US);
Seagate Technology, Inc., Scotts Valley, CA (US);
Abstract
An adaptive, analog filter system of a PRML [PARTIAL RESPONSE MAXIMUM LIKELIHOOD ] read channel of a disc drive comprising an adaptive, analog transversal equator connected in series with an adaptive, analog prefilter. The prefilter is comprised of a plurality of serially connected, adaptive, analog filter stages having variable transfer functions determined by adaptive parameter signals received by the filter stages. The transversal equalizer is comprised of a delay circuit, comprised of a plurality of serially connected, adaptive, analog sixth order low pass filters, that is tapped to either side of each low pass filter, a plurality of analog multipliers that receive signals at the tap locations of the delay circuit, and a summing circuit that receives the outputs of the multipliers. The transfer functions of the sixth order low pass filters are continuously variable in relation to adaptive parameter signals received by the low pass filters and the gains of the multipliers are continuously variable in relation to tap weights received by the multipliers.