STT-MRAM Sensing: A Review

This brief presents a review of developments in spin-transfer-torque magnetoresistive random access memory (STT-MRAM) sensing over the past 20 years from a circuit design perspective. Various sensing schemes are categorized and described according to the data-cell variation-tolerant characteristics, pre-amplifiers, and offset tolerance. Key breakthroughs for achieving the optimal reference scheme, read disturbance prevention, read energy reduction, accurate yield estimation, and overcoming other non-idealities are discussed. This review is intended to facilitate further enhancement of STT-MRAM sensing in advanced technology nodes, thereby fulfilling STT-MRAM's potential as a universal memory.