IP개요 |
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 (VDD). This paper analyzes state-of-the-art NV-FFs according to VDD and size and proposes a novel cross-coupled NMOS sensing circuit based NV-FF that is capable of operating in near/sub-threshold voltage region. Monte Carlo HSPICE simulation results based on industry-compatible 65-nm model parameters reveals that the proposed NV-FF can achieve a 33x improvement in the restore yield when compared with the previous cross-coupled-inverter sensing circuit. |