High-Throughput/low-energy mtj-based true random number generator using a multi-voltage/current converter

Naoya Onizawa, Shogo Mukaida, Akira Tamakoshi, Hitoshi Yamagata, Hiroyuki Fujita, Takahiro Hanyu

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


This article introduces high-Throughput/low-energy true random number generators (TRNGs) based on CMOS and three-Terminal magnetic tunnel junction (MTJ) devices. MTJs are fast and probabilistic switching devices, which can be used as random number sources for TRNGs. However, as the switching probability is quite sensitive to the write current given to MTJs, precise closed-loop control is necessary. Thus, a high-complexity current control circuit is required, such as high precision digital-To-Analog converters (DACs), occupying large area and causing large energy dissipation. In order to address the issue, we propose a multi-voltage/current ( V/I ) converter capable of multilevel coarse current switching and fine adjusting within each level. The fine adjusting can be done by DACs with fewer bits, resulting in much smaller size and energy dissipation than a conventional single-V/I converter. In addition, a multiple-writing scheme for three-Terminal MTJs is proposed for increasing the throughput while maintaining the write power. The proposed TRNGs are designed using TSMC 65-nm CMOS and a three-Terminal MTJ model that achieves a throughput of 333 Mb/s, an energy dissipation of 0.66 pJ/bit and an area of 2040~\mu {\rm m^{2}}. This result exhibits a 5\times throughput, a 93% energy reduction and an 86% area reduction in comparison with a conventional CMOS/MTJ-based TRNG.

Original languageEnglish
Article number9146172
Pages (from-to)2171-2181
Number of pages11
JournalIEEE Transactions on Very Large Scale Integration (VLSI) Systems
Issue number10
Publication statusPublished - 2020 Oct


  • Internet of Things (IoT) device
  • magnetic tunnel junction (MTJ)
  • true random number generator (TRNG)

ASJC Scopus subject areas

  • Software
  • Hardware and Architecture
  • Electrical and Electronic Engineering


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