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:
Nov. 22, 2011
Filed:
Oct. 21, 2009
Keizo Morita, Kawasaki, JP;
Kenichi Nakabayashi, Kawasaki, JP;
Keizo Morita, Kawasaki, JP;
Kenichi Nakabayashi, Kawasaki, JP;
Fujitsu Semiconductor Limited, Yokohama, JP;
Abstract
A voltage detection circuit outputs a detection signal when an amount of charges read to one of a pair of bit lines reaches a predetermined amount. A mask circuit of a timing generator masks an output of a sense amplifier activation signal until the detection signal is output. A sense amplifier determines logics of data read to the bit lines from memory cells in synchronization with the sense amplifier activation signal. An operation of the sense amplifier is started after predetermined amounts of charges are read from the memory cells to the bit lines, that is, after the detection signal is output. Accordingly, even when a timing to output a timing signal becomes early due to a variance of manufacturing conditions of a semiconductor memory, data read from the memory cells can be latched correctly in the sense amplifier. As a result, malfunctions of the semiconductor memory can be prevented.