Non-volatile semiconductor memory device capable of high speed programming/erasure
Patent 5818761 Issued on October 6, 1998. Estimated Expiration Date: 
July 18, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 18, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesEPROM source bias circuit with compensation for processing characteristics High-speed memory with a limiter of the drain voltage of the cells Memory programming load-line circuit with dual slope I-V curve Voltage regulator for non-volatile semiconductor memory devices Patent #: 5576990 InventorsApplicationNo. 897101 filed on 07/18/1997US Classes:365/185.18, Particular biasing365/185.11, Bank or block architecture365/185.13, Global word or bit lines365/185.24Threshold setting (e.g., conditioning)ExaminersPrimary: Hoang, HuanAttorney, Agent or FirmInternational ClassG11C 016/04Foreign Application Priority Data1996-09-10 JPAbstractTo a column line to which a selected memory cell is connected, a write bias voltage is supplied through a selection gate transistor having different channel conductivity type than the memory cell transistor. Current drivability of the selection gate transistor is adapted to be larger than a leak current of the memory cell and to supply a current smaller than the channel current when a channel is formed in one aspect. When a verifying voltage is applied to the selected word line, a large channel current flows when a channel is formed, potential of a subbit line is changed accordingly, and programming is suppressed. In another aspect, the selection gate transistor serves as a constant current source to make the programming speed of the memory cells constant. Thus distribution of threshold values after programming can be made narrow.Other References
| |
