A New Reference Cell for 1T-1MTJ MRAM

We propose a novel sensing scheme, which operates by sensing the difference in voltage between a memory cell and a reference cell for a magnetoresistive random access memory (MRAM). A new midpoint-reference generation circuit is adopted for the reference cell to improve the sensing margin and to guarantee correct operation of sensing circuit for wide range of tunnel magneto resistance (TMR) voltages. In this scheme, the output voltage of the reference cell becomes nearly the midpoint between the cell voltages of high and low states even if the voltage across the magnetic tunnel junction (MTJ) varies.