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:
Jun. 22, 1999
Filed:
May. 09, 1997
Douglas R Peterson, Minnetonka, MN (US);
VTC Inc., Bloomington, MN (US);
Abstract
A preamplifier circuit, which produces an output signal representative of signals from a magnetoresistive read head, includes a current bias circuit for providing a bias current to the read head, and first and second amplifiers for amplifying signals from the read head. The first amplifier, with an input for coupling to the read head, outputs first signals representative of changes in head resistance. The first signals have an amplitude substantially independent of the head resistance and proportional to a temperature dependent characteristic of the first amplifier. The second amplifier, which is coupled to the first amplifier, outputs a second signal having an amplitude proportional to the amplitude of the first signals and inversely proportional to the temperature dependent characteristic. Thus, the amplitude of the second signal is substantially independent of head resistance and the temperature dependent characteristic.