PHASE CHANGE MEMORY DEVICE

摘要

A phase change memory device is provided to improve stability and accuracy of a reference current by using a reference cell array to form the same condition as a cell array. A reference global bit line is shared by a plurality of reference bit lines. A reference cell array is formed in an intersection region of the reference bit line and a word line and outputs the reference current. A main cell array includes the phase change resistance cell in the intersection region of the plurality of the bit lines and the word line. A sense amplifier is connected to the plurality of bit lines. The reference current and the cell data current of the main cell array are applied to the sense amplifier. A light driving part supplies a driving voltage corresponding to the light data to the plurality of bit lines. A bit line precharge unit(100) pre-charges the reference global bit line and the global bit line according to a bit line precharge control signal. A global column switching unit(200) selects the corresponding global bit line according to the global column selection signal. A lead voltage controller(300) supplies a bit line lead voltage to the reference global bit line and the global bit line according to the lead control signal. A lead voltage generator(400) generates the bit line lead voltage according to a clamp voltage.