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:
Jul. 10, 2001
Filed:
Feb. 22, 1999
Kazushi Tsuwako, Machida, JP;
Yoshiro Amano, Yokohama, JP;
Takao Matsui, Yamato, JP;
Tsuyoshi Miura, Fujisawa, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A preamplifier circuit to improve the ESD immunity of magnetic recording devices having magnetoresistive (MR) sensors, without degrading the sensor's high-frequency characteristics. The preamplifier circuit is coupled to an MR sensor having one terminal grounded. The preamplifier circuit includes a varistor coupled between a power supply line and a ground terminal. If a high voltage, exceeding the varistor voltage, is applied to the chassis (ground), it is discharged through the varistor between the power supply voltage line and the ground terminal, instead of through the MR head or the arm electronics module. The present invention thereby protects the MR head and the arm electronics module from ESD damage.