Analog to Stochastic Bit Stream Converter Utilizing Voltage-Assisted Spin Hall Effect

H. Lee*, A. Lee, F. Ebrahimi, P. Khalili Amiri, K. L. Wang

*Corresponding author for this work

Research output: Contribution to journalArticle

11 Scopus citations


We introducea spintronic analog to stochastic bit stream (SBS) converter (ASC) based on a three terminal magnetic tunnel junction (MTJ) with a heavymetal layer. The critical current of the spin Hall effect (SHE) for switching the MTJ is efficiently modulated by applying a voltage across the MTJ via the voltage-controlled magnetic anisotropy effect. This effect results in the switching probability linearly depending on the amplitude of the analog input signal of the ASC. There are several advantages of using the voltage-assistedSHE for generating an SBS. The stochastic switching behavior of MTJ devices drastically reduces the area overhead by simplifying control circuits in the ASC. Moreover, the voltage-assisted SHE switching improves energy efficiency over traditional spin transfer torque (STT)-based MTJ switching by diminishing ohmic dissipation. Also, multiple MTJs on a single heavy metal layer increases the bandwidth by simultaneously converting analog input signals to SBSs. The performance of the spintronic ASC was evaluated by using the macrospin three terminal MTJ compactmodel integrated into a 45-nm CMOS technology. The proposed ASC can achieve 7x reduction in power consumption comparedto the previousSTT-basedwork and significant improvement in area-efficiency compared with the pure CMOS-based design.

Original languageEnglish (US)
Article number7990039
Pages (from-to)1343-1346
Number of pages4
JournalIEEE Electron Device Letters
Issue number9
StatePublished - Sep 2017


  • Analog to stochastic bit stream converter
  • magnetic tunnel junction
  • spin hall effect
  • voltage-controlled anisotropy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

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