Patent ID: 6490200
Filing Date: 2002-12-03
Classification: G11C

Abstract:
In a non-volatile memory comprising an array of memory cells, each memory cell having a source, a drain, a charge storage and a control gate, said charge storage receptive to variable amount of charges being stored therein for designating one of a plurality of memory states, a method of sensing one of said plurality of memory states of a memory cell, comprising:applying predetermined voltages respectively to the source, the drain and the control gate of said memory cell being sensed, thereby producing a source-drain current relative to the amount of charges stored in the charge storage of said memory cell being sensed, said source-drain current having an inherent noise fluctuation component; and obtaining an average value of said source-drain current over a predetermined period of sensing time sufficient for the noise fluctuation component therein to cancel to a predetermined level; determining whether said average value of said source drain current is higher or lower than a predetermined value.