Title :
A switched-current sensing architecture for a four-state per cell magnetic tunnel junction MRAM
Author :
Au, Edward K S ; Ki, Wing-Hung ; Mow, Wai Ho ; Hung, Silas T. ; Wong, Catherine Y.
Author_Institution :
Dept. of Electr. & Electron. Eng., Hong Kong Univ. of Sci. & Technol., China
Abstract :
A current-mode binary-search sensing scheme for a four-state per cell one-transistor one-magnetic tunnel junction magneto-resistive (MR) random access memory is proposed. By using the switched-current technique, it is able to read data nondestructively with a MR ratio as low as 5%. The sensing circuit is designed using a 0.18-μm CMOS process and the performance is verified by HSPICE simulation. At a supply voltage of 1.8 V, the data can be accessed in 17.5 ns with a power consumption of 475.9 μW. Compared to the parallel sensing approach, the proposed sensing scheme consumes less power and chip area, and requires fewer comparison steps. Compared to the conventional serial sensing approach, it allows a shorter read access time while performing the same number of comparisons.
Keywords :
CMOS integrated circuits; current-mode circuits; magnetic storage; magnetoresistive devices; random-access storage; switched current circuits; 0.18 micron; 1.8 V; 475.9 muW; CMOS process; HSPICE simulation; binary-search sensing scheme; magnetic tunnel junction; magneto-resistive random access memory; parallel sensing approach; read access time; search methods; sensing circuit; switched-current sensing architecture; switched-current technique; CMOS process; Circuit simulation; Gold; Magnetic materials; Magnetic switching; Magnetic tunneling; Magnetization; Materials science and technology; Random access memory; Voltage; 65; MRAM; Magneto-resistive random access memory; SI; search methods; switched-current; technique;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2004.836868
