Patent · US Expired

Nonvolatile semiconductor memory for positively holding stored data

US5519652A · kind A · utility

20Cited by
0References
18Claims
0Family size

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Inventors

Key dates

Filing dateDec 1, 1993
Grant dateMay 21, 1996
Priority date
Expiry dateDec 1, 2013

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C2029/5006
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A semiconductor memory has a plurality of word lines, a plurality of bit lines, a plurality of memory cells, a differential sense amplifier, and load transistors. Each of the memory cells is a MIS transistor formed at each intersection of the word and bit lines. The threshold voltage of the MIS transistor is externally electrically controllable. The differential sense amplifier senses data stored in a selected memory cell located at an intersection of selected word and bit lines. A control pulse signal is applied to the gates of the load transistors, to bias the bit lines. The pulse width of the control pulse signal is a minimum essential to read data out of the selected memory cell. The control pulse signal controls the switching of the load transistors, to shorten a period during which a stress voltage is continuously applied to the drains of unselected memory cells that are connected to the bit line to which the selected memory cell is connected.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.