Patent · US Expired

Nonvolatile memory circuit device performing stable operation in wide range of power source voltage level

US4972378A · kind A · utility

18Cited by
2References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 20, 1989
Grant dateNov 20, 1990
Priority date
Expiry dateJun 20, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C16/28
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

An electrically programmable nonvolatile memory circuit device includes a plurality of memory cell transistors from which data is read out, dummy cell transistors which are each selectively operated at the same time as the operation of a selected one of said memory cell transistors in the same condition as the selected memory cell transistor at the time of reading out data from the selected memory cell transistor, and a sense amplifier including a logic gate circuit for converting the programming state of the memory cell transistor into a logic value based on a difference between the current characteristics of the memory cell transistor and the dummy cell transistor. When the source-drain current of the memory cell transistors set in the non-programmed state is denoted by I1, the source-drain current of the dummy cell transistor is denoted by I2, and the source-drain current of the memory cell transistors set in the programmed state is denoted by I3, then currents I1, I2 and I3 are so set as to satisfy the current relation of "I1>I2>I3".

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