1.8-V nanospeed R/W module for 64-kB cross-point cell magnetic random access memory

Cross-point (CP) magnetic random access memory (MRAM) is a promising nonvolatile memory cell for lower cost high-density data-storage applications because the CP cell comprises one magnetic tunnel junction (MTJ) only without a transistor. It is difficult to read/write (R/W) a selected data without large mount of leakage current through adjacent mesh resistive loop while the bit line and the word line are electrically coupled through the CP MTJs in the array that are completely electrically unisolated. A novel scheme of high-speed R/W circuitry with no steady leakage for cross-point cell MRAM is proposed. A novel cell R/W circuitry with a sense amplifier is developed and incorporated into a 64-kB CP MRAM which using MTJs is designed with 15 kOhm resistance and a 50% magnetoresistance ratio. The proposed scheme with low power consumption is verified by a 0.18-mum Taiwan Semiconductor Manufacturing Company complementary metal-oxide semiconductor SP5M technology.