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. 22, 2002
Filed:
Apr. 14, 1995
Douglas R. Peterson, Minnetonka, MN (US);
Agere Systems Guardian Corp., Orlando, FL (US);
Abstract
A preamplifier for an MR element having first and second ends includes first and second feedback loops controlling the biasing of the MR element. The first feedback loop responds to a center voltage of the MR element to control a current source coupled to the first end of the MR element, and the second feedback loop responds to an output voltage across the MR element to control a current sink coupled to the second end of the MR element. In one embodiment, the preamplifier includes a multiplexer coupled between first and second MR elements and the first and second feedback loops. The multiplexer electrically isolates the first and second MR elements to improve common-mode rejection and feedback performance of the preamplifier.