Patent · US Expired

Sensing scheme for flash memory with multilevel cells

US5748546A · kind A · utility

42Cited by
54References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 10, 1997
Grant dateMay 5, 1998
Priority date
Expiry dateApr 10, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C2211/5632
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Methods and apparatus for determining the state of a memory cell having more than two possible states are disclosed. For a first embodiment, the state of a flash cell having n states, where n is a power of 2, is determined by selectively comparing the threshold voltage V.sub.t of a selected memory cell to (n-1) reference voltages. For every two states, a single comparator is provided such that the total number of comparators is equal to the number of bits stored in the memory cell.

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