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:
Apr. 09, 1991
Filed:
Mar. 21, 1988
Applicant:
Inventors:
Laszlo V Gal, Poway, CA (US);
James E Judy, Jr, San Diego, CA (US);
Kenneth C Prentiss, San Diego, CA (US);
Assignee:
Unisys Corporation, Blue Bell, PA (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01R / ; G01R / ;
U.S. Cl.
CPC ...
3241 / ; 3241 / ;
Abstract
A module for preventing instability in systems which test integrated circuit chips resides between the tester unit and the chip that is being tested. This module is characterized as including a plurality of phase-shifting circuits which couple respective output signals from output transistors on the chip onto signal lines to the tester unit. Each phase-shifting circuit includes an inductor which counteracts and cancels any capacitive phase shift that is produced by the input impedance of the corresponding signal line to the tester unit.