PHASE CHANGE MEMORY DEVICE HAVING A PLURALITY OF REFERENCE CURRENTS AND OPERATING METHOD THEREOF

摘要

A phase change memory device includes a cell array unit including a phase change resistance cell positioned at an intersection of a word line and a bit line. A plurality of sense amplifiers sense and amplify data of the phase change resistance cell selected using a plurality of reference currents. A plurality of comparing units compare an output signal of the corresponding sense amplifier with that of the neighboring sense amplifier so as to output a flag enable signal.