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:
Oct. 20, 1992
Filed:
Jan. 31, 1991
Kowk Fai Lee, Irvine, CA (US);
Alan Lee, Irvine, CA (US);
Western Digital Corporation, Irvine, CA (US);
Abstract
An electrostatic discharge protection circuit for an integrated circuit employing a segmented field effect buffer transistor between the input/output pad and the active devices on the integrated cicuit. An extended resistive structure is configured in series with the segmented buffer transistor and the input/output electrical contact pad. The extended resistive structure is integrally formed with the individual segments of the buffer FET. The resistive structure may be implemented as an extended n well structure adjacent the FET segments. In a first resistance mode during normal circuit operations, the extended resistive structure has a low resistance value and introduces virtually no additional load to the input/output buffer circuitry. In a second mode of operation during ESD discharge, the resistive structure has a second significantly higher resistance which reduces current values during the ESD event thereby protecting the buffer circuit. A thick oxide snap-back device is also employed to provide a parallel EDS discharge path with low power dissipation.