Static information storage and retrieval – Read/write circuit – Including level shift or pull-up circuit
Reexamination Certificate
2008-04-08
2008-04-08
Nguyen, Tuan T. (Department: 2824)
Static information storage and retrieval
Read/write circuit
Including level shift or pull-up circuit
C365S188000, C365S063000
Reexamination Certificate
active
07355906
ABSTRACT:
A novel semiconductor SRAM cell structure that includes at least two pull-up transistors, two pull-down transistors, and two pass-gate transistors. In one embodiment, an 8T SRAM cell structure implements a series gating feature for implementing Column Select (CS) and Row Select (WL) cell storage access with enhanced stability. Particularly, the 8-T approach adds two pass-gates, two series connected transistor devices connected at complementary nodes of two cross-coupled inverters, to control column select and row (word) select. In the other embodiment, a 9T SRAM cell structure includes a transmission gate to implement Column Select (CS) and Row Select (WL) cell storage access with enhanced stability. The 9-T approach adds three transistors to perform ANDING function to separate the row select and column select signal functions. Both methods improve stability by eliminating half-select mode and facilitate rail to rail data transfer in and out of the SRAM cell without disturbing the other cells.
REFERENCES:
patent: 5774411 (1998-06-01), Hsieh et al.
patent: 5923582 (1999-07-01), Voss
patent: 6091626 (2000-07-01), Madan
patent: 6341083 (2002-01-01), Wong
patent: 6507511 (2003-01-01), Barth, Jr. et al.
patent: 6510076 (2003-01-01), Lapadat et al.
patent: 6552941 (2003-04-01), Wong et al.
patent: 6888741 (2005-05-01), Wong
patent: 6920061 (2005-07-01), Bhavnagarwala et al.
patent: 6934182 (2005-08-01), Chan et al.
patent: 7019999 (2006-03-01), Srinivasan et al.
patent: 2005/0063232 (2005-03-01), Chan et al.
patent: 2005/0078508 (2005-04-01), Chan et al.
patent: 2007/0025140 (2007-02-01), Redwine
Joshi Rajiv V.
Tan Yue
Wong Robert C.
Abate Esq. Joseph P.
International Business Machines - Corporation
Nguyen Tuan T.
Scully , Scott, Murphy & Presser, P.C.
LandOfFree
SRAM cell design to improve stability does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with SRAM cell design to improve stability, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and SRAM cell design to improve stability will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2798376