Reference-scheme study and novel reference scheme for deep submicrometer STT-RAM

Taehui Na, Jisu Kim, Jung Pill Kim, Seung H. Kang, Seong Ook Jung

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

As technology scales down, the sensing margin of spin-transfer-torque random access memory is significantly degraded because of the increased process variation and decreased supply voltage. The sensing current, which is limited to prevent read disturbance, further degrades the sensing margin. To improve the sensing margin, various reference schemes have been proposed. However, it is essential to be selective because the read stability, write ability, and array efficiency are very different according to the reference schemes. This paper presents the study of a variety of reference schemes and outlines five requirements for an optimized reference scheme as follows: 1) no parasitic mismatch, 2) no regularity problem, 3) no read disturbance, 4) no write-current degradation, and 5) small area overhead. A novel reference scheme that satisfies all the requirements for the optimized reference scheme is proposed using four 1T1MTJ cells and a reference word line structure with the same parasitic scheme.

Original languageEnglish
Article number6853380
Pages (from-to)3376-3385
Number of pages10
JournalIEEE Transactions on Circuits and Systems I: Regular Papers
Volume61
Issue number12
DOIs
Publication statusPublished - 2014 Dec

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All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

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