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:
Aug. 07, 2001
Filed:
Feb. 16, 1999
Paul Wingshing Chung, San Jose, CA (US);
Stephen Alan Jove, Watsonville, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A multi-state preamplifier having a first detector and a second detector provides voltage-sensing and current-sensing signal amplification, respectively. Either the first detector or the second detector is selected and switched active at any given time, producing an amplified signal representing either the signal voltage developed across the MR element or the signal current flowing through the MR element, respectively. The switching process to activate either the first detector or the second detector is carried out by a detector determining circuit connected to a disk drive control unit. The detector giving the optimum high frequency bandwidth for the preamplifier is chosen based on the resistance of the MR element coupled with the input interconnect network characteristic and parasitic impedances.