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. 23, 1997
Filed:
Nov. 27, 1995
Applicant:
Inventors:
Maho Urano, Tokyo, JP;
Miho Yokota, Tokyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K / ;
U.S. Cl.
CPC ...
364482 ; 364489 ; 364578 ;
Abstract
An apparatus and method for checking logic circuit checks logic element influenced by hot carriers in the logic circuit. The present invention comprises means for measuring rising transition time t.sub.r (or falling transition time t.sub.f) of signal generated by logic element comprising one portion of the logic circuit; means for calculating a ratio (DUTY) of rising transition time t.sub.r (or falling transition time t.sub.f) and operation period T of the signal; and means for comparing said DUTY with maximum allowable duty (DUTYMAX), in order to detect the logic element having DUTY exceeding maximum allowable duty (DUTYMAX).