Impact of external magnetic fields on STT-MRAM

Bernard Dieny; Sanjeev Aggarwal; Vinayak Bharat Naik; Sebastien Couet; Thomas Coughlin; Shunsuke Fukami; Kevin Garello; Jack Guedj; Jean Anne C. Incorvia; Laurent Lebrun; Kyung-Jin Lee; Daniele Leonelli; Yonghwan Noh; Siamak Salimy; Steven Soss; Luc Thomas; Weigang Wang; Daniel Worledge

arXiv · 2409.05584

Impact of external magnetic fields on STT-MRAM

Bernard Dieny·Sanjeev Aggarwal·Vinayak Bharat Naik·Sebastien Couet·Thomas Coughlin·Shunsuke Fukami·Kevin Garello·Jack Guedj·Jean Anne C. Incorvia·Laurent Lebrun·Kyung-Jin Lee·Daniele Leonelli·Yonghwan Noh·Siamak Salimy·Steven Soss·Luc Thomas·Weigang Wang·Daniel Worledge

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Abstract

This application note discusses the working principle of spin-transfer torque magnetoresistive random access memory (STT-MRAM) and the impact that magnetic fields can have on STT-MRAM operation. Sources of magnetic field and typical magnitudes of magnetic fields are given. Based on the magnitude of commonly encountered external magnetic fields, we show below that magnetic immunity of STT-MRAM is sufficient for most uses once the chip is mounted on a printed circuit board (PCB) or inserted in its working environment. This statement is supported by the experience acquired during 60 years of use of magnetic hard disk drives (HDD) including 20 years of HDD with readers comprising magnetic tunnel junctions, 20+ years of use of magnetic field sensors as position encoders in automotive industry and 15+ years of use of MRAM. Mainly during chip handling does caution need to be exercised to avoid exposing the chip to excessively high magnetic fields.

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Bernard Dieny, Sanjeev Aggarwal, Vinayak Bharat Naik, Sebastien Couet, Thomas Coughlin, Shunsuke Fukami, Kevin Garello, Jack Guedj, Jean Anne C. Incorvia, Laurent Lebrun, Kyung-Jin Lee, Daniele Leonelli, Yonghwan Noh, Siamak Salimy, Steven Soss, Luc Thomas, Weigang Wang, Daniel Worledge. 2024-09-09. Impact of external magnetic fields on STT-MRAM. https://arxiv.org/abs/2409.05584

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