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 9 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
Multichannel device utilizing a centralized out-of-band authentication system (COBAS)
Preservation of liquid foods
Towel clip
Apparatus for merging spatial audio streams
Carbonate and carbamate modified forms of glucocorticoids in combination with .beta..sub.2 adrenergic agonists
Systems, methods, and computer readable media for providing information related to virtual environments to wireless devices
Formation of an optical waveguide
  Randomly Featured Patents
Method of manufacturing semiconductor device
Advertising apparatus
Metadata structure for providing access to EPG features from within broadcast advertisements
Method for measuring antigen concentration
Phthalazine derivatives and remedies for erectile dysfunction
Method and apparatus for control of critical dimension using feedback etch control
Surgical support apparatus with splined coupling, cross bar support and head-to-toe extension for surgical retractor apparatus
Medical vials
Method and apparatus for interrupt redirection for arm processors
Floating magnetic head