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. 29, 1980
Filed:
Aug. 03, 1978
George W Brown, San Jose, CA (US);
Thomas L Reynolds, Sunnyvale, CA (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
A sense amplifier and sensing scheme for sensing the normal or blown condition of fuses in a programmable read only memory (PROM) or similar device. A sensing circuit is provided with a threshold level separating high and low input levels indicative of the fuse condition. The sensing circuit has one circuit branch with a first current mirror with a temperature characteristic which provides a threshold level which is slightly divergent with reference to a low level input. Another circuit branch clamps the high input level to the slightly divergent threshold level and uses a second current mirror with a temperature characteristic which provides a high level slightly more divergent than the threshold level. By selecting mirror currents proportionally, high level and threshold level temperature characteristic divergence can be proportionally controlled in selected amounts with respect to the low level. Current sources for the sense amplifier are made to offset voltage fluctuations, making the sense amplifier highly insensitive to voltage fluctuations in addition to temperature variations.