Separated Precharge Sensing Amplifier for Deep Submicrometer MTJ/CMOS Hybrid Logic Circuits

Magnetic tunnel junction (MTJ) embedded in complementary metal-oxide-semiconductor (CMOS) has been considered as one of the potentially powerful solutions to build up nonvolatile memory and logic circuits. It possesses many intrinsic merits, such as high speed, instant on/off, good scalability and low-leakage power, and promises to extend the Moore's law. A critical issue in this hybrid MTJ/CMOS structure is the reliable integration of MTJ electric signals to CMOS electronics, especially for the deep submicrometer technology nodes (e.g., 28 nm) in presence of low supply voltage and serious process variations. In this paper, we propose a new sensing amplifier, named separated precharge sense amplifier. This circuit, by separating the discharging and evaluation stages of the sensing operation, can operate at a lower supply voltage (< 1.0 V) and reduces the effects of process variations as technology scales, thereby providing higher sensing reliability compared with the previously proposed solutions while preserving the high-speed and low-power consumption. Transient and Monte-Carlo statistical simulations are performed to demonstrate its sensing performance.