Low-power and high-sensitivity magnetoresistive random access memory sensing scheme with body-biased preamplifier

In this paper, we describe a new magnetoresistive random access memory (MRAM) sensing scheme with a body-biased preamplifier for low-power and high-sensitivity operation. The proposed new MRAM sense amplifier consists of a current sense preamplifier with a body biasing differential pair of a common-gate amplifier and a voltage sense amplifier. The preamplifier controls bitline voltage appropriately and amplifies the difference in bitline current as current-mode sense amplifier. The new sense amplifier enhances sensitivity, and the body-biased preamplifier enables low-voltage operation. To evaluate the proposed circuit, the modeling of magnetic tunnel junction (MTJ) resistance characteristics was performed with a VHDL-AMS description, and the proposed circuit was simulated with a mixed signal circuit simulator. From the simulation result, it is confirmed that the proposed sensing scheme results in a 1.57 times faster access time than a conventional scheme, and that the power of the sense amplifier is lower than that of the conventional amplifier at the same speed.