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. 29, 2002
Filed:
Sep. 17, 1999
Giuseppe Patti, San Jose, CA (US);
Gilles Denoyer, Campbell, CA (US);
Roberto Alini, San Jose, CA (US);
STMicroelectronics, Inc., Carrollton, TX (US);
Abstract
An apparatus (and method) is provided that reduces thermal interference in the read signal of a disk drive. A variable or programmable resistance is used to change the transfer function of a filter in the read channel of the disk drive to filter the read signal. The filter has a first transfer function (first cut-off frequency) related to the programmed resistance during normal operation of the disk drive (i.e. when thermal interference is not detected). When thermal interference is detected in the read signal, the resistance is programmed to another value resulting in the filter having a second transfer function (second cut-off frequency). The resistance element includes a transconductance amplifier whose transconductance is variable or programmable to different values resulting in different programmable transfer functions (or one of a multitude of cut-off frequencies) for the filter. In the preferred embodiment, detection of thermal interference increases the cut-off frequency of the filter thereby filtering, or reducing the effects of, the thermal interference in the read signal.