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:
Mar. 14, 2000
Filed:
May. 19, 1998
Richard E Crippen, Mountain View, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
An electrostatic discharge (ESD) protection circuit for the output pads of an integrated circuit. The protection circuit includes an NMOS output transistor, an NMOS protection transistor and an NMOS bias transistor. The output and protection transistors are preferably embodied in a common merged transistor structure and have common drains connected to the output pad and common sources connected to the integrated circuit common. The bias transistor controls the gate-source bias of the protection circuit and operates to cause the output and the protection transistors to conduct current in proportion to the relative size of the transistors thereby maximizing the protection against damage by ESD.