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:
Feb. 20, 2007
Filed:
Jun. 17, 2005
Keizo Morita, Kawasaki, JP;
Keizo Morita, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
The semiconductor memory has word lines; normal memory cells each having a storage capacitor; normal bit lines connected to the normal memory cells; a reference memory cell having a capacitor storing prescribed data; and a reference bit line connected to the reference memory cell. When a word line is selected, the potential of normal bit lines and of reference bit line changes according to the charge on the storage capacitors and on the reference capacitor. A current mirror circuit is also provided, which has a first transistor drain of which is connected to the reference bit line and second transistors drains of which are respectively connected to normal bit lines, the gates of the first and second transistors being connected in common to the reference bit line. Thus even though the capacitance values of ferroelectric capacitors is scattered, the scattering in bit line potentials during read operations can be prevented.