MRAM Cell Technology for Over 500MHz SoC

Abstract

We propose two new MRAM cell structures, 2T1MTJ and 5T2MTJ. Although they enable very high-speed operation, they require small-write-current magnetic tunnel junctions (MTJs). We found that write current could be reduced to 1mA by a novel MTJ into which a write line is inserted. The 5T2MTJ cell has two write current switches and a sense circuit. Simulation results show that access time of under 1ns is achieved when the magnetic resistance is 5k-ohm and its ratio (MR) is 150%