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:
Jul. 20, 2004
Filed:
Sep. 25, 2000
Kazuhiro Sakaguchi, Tokyo, JP;
NEC Electronics Corporation, , JP;
Abstract
A unit test signal having duration T is repeatedly supplied from an LSI tester to an IC under test and, simultaneously, a power source current is supplied from the LSI tester through a current detection unit to the IC under test. The power source current is monitored by the current detection unit and a current information obtained by the monitoring is analyzed by a spectrum analyzer unit. Since the repetition period of the test signal is T, the power source current having a period nT flows through the IC under test along with a state shift of the IC under test, where n is an integer. When the IC under test has a fault, the power source current flows with a period n′T, where n′ is an integer different from n, or an abnormal power source current flows with the period nT, due to a change of the state shift of the IC under test. A decision unit performs a fault decision of the IC under test by judging an existence of abnormal power source current or the change of the state shift of the IC under test on the basis of values of spectral power in the vicinity of a frequency 1/nT and high harmonics thereof of the power source current or existence or absence of peak having such period.