Static information storage and retrieval – Floating gate – Particular biasing
Reexamination Certificate
2011-04-05
2011-04-05
Ho, Hoai V (Department: 2827)
Static information storage and retrieval
Floating gate
Particular biasing
C365S185250, C365S185050, C365S185170, C365S185180, C365S185210
Reexamination Certificate
active
07920428
ABSTRACT:
Methods and apparatuses for automatically measuring memory cell threshold voltages are disclosed. Measurement circuitry includes an internal reference current generator, a plurality of memory cells and a bit line pre-charge reference circuit. If the reference current is greater than the memory cell current, the bit line voltage will increase. Conversely, if the reference current is less than the memory cell current, the bit line voltage will decrease. The reference current is generated in large steps until a comparator, that compares the bit line voltage and a bit line pre-charge reference voltage, is switched. The reference current then generates a current in small steps until the comparator is again switched. The reference current converges on the memory cell current within an accuracy of 10 nA. The memory cell threshold voltage is then determined from the memory cell current. Systems including memory according to an embodiment of the invention are also disclosed.
REFERENCES:
patent: 5587948 (1996-12-01), Nakai
patent: 5600594 (1997-02-01), Padoan et al.
patent: 5615154 (1997-03-01), Yamada
patent: 5956277 (1999-09-01), Roohparvar
patent: 5966330 (1999-10-01), Tang et al.
patent: 6205057 (2001-03-01), Pan
patent: 6226200 (2001-05-01), Eguchi et al.
patent: 6285598 (2001-09-01), Khan et al.
patent: 6324094 (2001-11-01), Chevallier
patent: 6496415 (2002-12-01), Tsao
patent: 6542409 (2003-04-01), Yamada
patent: 6580644 (2003-06-01), Chung
patent: 6714453 (2004-03-01), Cavaleri et al.
patent: 6781884 (2004-08-01), Yamada
patent: 6819612 (2004-11-01), Achter
patent: 6839279 (2005-01-01), Yamada
patent: 6912160 (2005-06-01), Yamada
patent: 6975542 (2005-12-01), Roohparvar
patent: 7031210 (2006-04-01), Park et al.
patent: 7038482 (2006-05-01), Bi
patent: 7483305 (2009-01-01), Yamada
patent: 2002/0118574 (2002-08-01), Gongwer et al.
patent: 2005/0105333 (2005-05-01), Park et al.
International Search Report dated Apr. 4, 2008, for International Application No. PCT/US2007/076246 (5 pages).
Graham Kretella
Ho Hoai V
Micro)n Technology, Inc.
TraskBritt
LandOfFree
Methods and apparatuses relating to automatic cell threshold... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods and apparatuses relating to automatic cell threshold..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods and apparatuses relating to automatic cell threshold... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2733230