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. 11, 1997
Filed:
Feb. 06, 1995
John H Quigley, Phoenix, AZ (US);
David F Mietus, Phoenix, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
An Input/Output (I/O) circuit (11) for an integrated circuit including Electrostatic Discharge Protection (ESD) circuitry is disclosed. A Silicon Controlled Rectifier SCR (30) is triggered by a transistor (36) which is scaled to an output transistor (24) of the I/O circuit (11) to shunt an ESD event. The SCR (30) couples between a pad (12) and a power supply line V.sub.SS. The transistor (36) is disabled. The triggering mechanism is voltage breakdown of the transistor (36) due to an ESD event. The SCR protection mechanism is process independent since the triggering mechanism is formed similarly to the output transistor (24) and thus breaks-down similarly. Zener diodes (26-29) are coupled to gates of the I/O circuit (11) and between the power supply lines. A phosphorous doping less than 5.0 E18 per cubic centimeter is used to form the cathode of zener diodes (26-29).