PHASE CHANGE MEMORY DEVICE

摘要

A phase change memory device with memory cells (2) formed by a phase change memory element (3) and a selection switch (4). A reference cell (2a) formed by an own phase change memory element (3) and an own selection switch (4) is associated to a group (7) of memory cells to be read. An electrical quantity of the group of memory cells is compared with an analogous electrical quantity of the reference cell, thereby compensating any drift in the properties of the memory cells.

主权项

1. A method of reading a memory device, the method comprising:
sequentially coupling each of a plurality of reference cells to a comparator, each of the reference cells being in a common row line with a respective one of a plurality of reference cells to which it is being compared, each of the reference cells being programmed to a pre-defined threshold voltage corresponding to a respective reference value; andcomparing an electrical behavior of each of the plurality of memory cells and of the sequentially coupled ones of the plurality of reference cells to determine a value of the memory cells being read.