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. 15, 1992
Filed:
Mar. 04, 1991
Hitoshi Kokubun, Tokyo, JP;
Abstract
A semiconductor memory which is capable of measuring a threshold voltage in a memory cell. The semiconductor memory comprises memory arrays having a plurality of memory cells arranged in a matrix, means for selecting the memory cell, and a sense amplifier for comparing a current flowing through the selected memory cell with a current flowing through a dummy cell and provides an output indicative of a resultant comparison value. The memory cells each include a first switching means having a first transconductance at the time '1' is written in the memory cell and having a second transconductance at the time '0' is written in the memory cell, the value of the second transconductance being greater than the value of the first transconductance. The dummy memory cell includes a second switching means having a third transconductance value of which is in the middle between values of the first and the second transconductance. The memory cells and the dummy cell each have a gate coupled to respective external terminals. A selected one of the terminals receives increasing voltage.