10-35 nanosecond magnetoresistive memories

Experimental results demonstrate that high read output levels in the range of ±10 mV can be achieved by increasing the MR (magnetoresistive) memory element size and using a suitable sense technique with a bridge circuit including a reference line. Large MR memory cells with a sense resistance of about 470 Ω have been synthesized by stringing eight 1.8×1.2-μm MR elements together. These were tested in a bridge formation to obtain signal levels as large as -11 mV and +7 mV, with an approximate settling time of 35 ns in a discrete circuit. The results obtained suggest the possibility of fabricating much faster MR memories in the integrated form, and calculations have indicated that access times as low as 10 ns can be achieved