Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Threshold voltage adjustment method of non-volatile semiconductor memory device and non-volatile semiconductor memory device










Image Number 5 for United States Patent #6879521.

It is intended to provide a nonvolatile semiconductor memory device which maintains the maximum number of over-erase memory cells which are conductive when adjusting the threshold voltage after data erase by controlling the gate voltage of a memory cell continuously in order to adjust the threshold voltage in a short time and a nonvolatile voltage adjustment method. There is formed a feedback loop for controlling the number of memory cells to be conductive in a memory cell group by controlling a gate voltage generating circuit through a differential amplifier from a drain terminal and the gate voltage generating circuit is controlled by the differential amplifier so as to maintain the drain voltage at a predetermined drain voltage VRF. A variable gate voltage can be controlled continuously by a feedback loop for controlling the variable gate voltage based on a difference voltage between the drain voltage and the predetermined drain voltage. Thus, effective threshold voltage adjustment operation is enabled corresponding to a current supply capacity regardless of the current supply capacity of the drain voltage generating circuit.








 
 
  Recently Added Patents
Method of fabricating crystal unit, crystal unit fabrication mask, and crystal unit package
Method and apparatus for policy-based network access control with arbitrary network access control frameworks
Pyrrolidine-1,2-dicarboxamide derivatives
Method and system for constructing a customized web analytics application
Respirator belt having bumper cushion
Eyeglasses
Image processing apparatus and method having defective pixel detection and correction ability
  Randomly Featured Patents
Method of manufacturing semiconductor device
Plant holder
Lid for container
Method of forming multilayered conductive layers for semiconductor device
Device for exchanging masks
Method of stabilizing a UVB absorbing compound, a stabilized UV absorber, and a cosmetic composition containing the same
Sawing apparatus of the pulpwood slasher type
Computer-based video recording and management system for medical diagnostic equipment
Divider using neural network
Multi-layered optical disk reading method using liquid crystal diffraction device