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:
Dec. 21, 1999
Filed:
Jun. 12, 1997
Robert J Schuelke, Lakeville, MN (US);
Crispin K Metzler, Hastings, MN (US);
VTC, Inc., Bloomington, MN (US);
Abstract
A preamplifier bias circuit for use in an AC coupled magnetoresistive read head amplifier which includes a pair of head contacts, a pair of amplifier inputs, a pair of coupling capacitors and a means for selectively shunting the amplifier inputs and rapidly charge the coupling capacitors. The pair of head contacts and the pair of amplifier inputs couple the preamplifier bias circuit to a magnetoresistive element and a read amplifier, respectively. Each of the coupling capacitors is connected between one of the head contacts and one of the amplifier inputs to block a static potential across the magnetoresistive element. The means for selectively shunting the amplifier inputs selectively provides a low impedance path to rapidly charge the coupling capacitors and clamps the amplifier inputs to a known potential. By selectively providing a low impedance path, the AC coupled magnetoresistive read head amplifier can be protected and its associated delay time prior to operation can be decreased.