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:
Aug. 18, 1992
Filed:
Aug. 30, 1990
John F Schreck, Houston, TX (US);
Phat C Truong, Houston, TX (US);
David Tatman, Missouri City, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A test circuit for determining whether or not fuse-links of an integrated circuit have been opened or closed properly by, for example, a laser device. The test circuit of this invention, in one embodiment, includes a variable impedance, such as a P-channel transistor, connected between a voltage source and an output terminal, the impedance having one value with a first input applied to the variable impedance control terminal and having a second, larger value in response to a second input applied to the variable impedance control terminal. At least one programmable fuse-link and a gate are connected in series between the output terminal and a source of reference potential. A means for providing control inputs to the variable impedance is connected between a test mode input signal and the control terminal of the variable impedance. The means for providing control inputs to the P-channel transistor may include a second, current-mirror-connected P-channel transistor.