A Dual-Swing-Sample-and-Couple Sense Amplifier With Large Sensing Margin for STT-MRAM

As technology node continues to shrink, the sensing margin of STT-MRAM is significantly diminished due to the downscaled supply voltage and increased process variations, posing challenges for sensing reliability. In this paper, a dual-swing-sample-and-couple sense amplifier is proposed to enhance the sensing margin and improve the read yield. By combining the data cell with two separate reference cells for sampling and coupling operations, the sensing margin is effectively doubled without pre-amplification. The simulation results demonstrate that the proposed circuit achieves a sensing margin up to 1.83 times that of conventional circuits, with a read yield of 99.9 at a sensing time of 2 ns. The read yield is not degraded at high temperatures (100 ∘ C), demonstrating high robustness. In addition, the extra power consumption induced by the preamplification operation is eliminated, effectively saving energy.