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:
Sep. 18, 1990
Filed:
Dec. 28, 1988
Applicant:
Inventor:
Thomas B Pritchard, Vancouver, WA (US);
Assignee:
Hewlett-Packard Company, Palo Alto, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05F / ;
U.S. Cl.
CPC ...
361212 ;
Abstract
The protection circuit of the invention connects differentiated grounds in an electronic system either by a single diode, or by two diodes arranged in a back-to-back, parallel fashion. The differentiated grounds may include a chassis ground, a logic ground and an earth ground. The circuit locally connects two of the differentiated grounds, thereby providing a low inductance path for the fast discharging of electrostatic charge build-ups, with the diode(s) therein providing the electrical separation necessary to provide proper local isolation between the interconnected grounds to enable filtering out of electromagnetic interference potentials.