Robust Offset-Cancellation Sensing-Circuit-Based Spin-Transfer-Torque Nonvolatile Flip-Flop

Nonvolatile flip-flop (NV-FF) based systems can be effectively implemented in battery-limited internet of things (IoT) applications due to their zero standby power consumption and instant ON/OFF characteristics. Among various NV-FFs, spin-transfer-torque magnetic tunnel junction based NV-FFs are the most applicable due to their nonvolatility, high endurance, complementary metal-oxide-semiconductor (CMOS) compatibility, scalability, and rapid sensing and write speed due to its low resistance. However, they are subject to a degraded sensing margin for restoring operation with technology shrinks because of the increased process variation and reduced supply voltage. This paper proposes a novel NV-FF with a significantly superior offset-tolerance and reduction in read current (I
_read
) that produces read disturbance in comparison to state-of-the-art NV-FFs. Monte Carlo HSPICE simulation results based on industry-compatible 65-nm model parameters revealed that the proposed NV-FF can achieve a three-order improvement in the restore yield and a two-order reduction in the I
_read
when compared with state-of-the-art NV-FFs.