Ultra-low power 32-bit pipelined adder using subthreshold source-coupled logic with 5 fJ/stage PDP

Armin Tajalli, Elizabeth J. Brauer, Yusuf Leblebici

Research output: Contribution to journalArticle

8 Scopus citations


This article presents a new approach for improving the power-delay performance of subthreshold source-couple logic (STSCL) circuits. Using a simple two-phase pipelining technique, it is possible to increase the activity rate of STSCL gates with negligible additional cost, and hence reduce the total system energy consumption per operation. In the proposed pipelined topology, each STSCL gate is followed by a simple cross-coupled differential pair operating as a state keeper with a very low power consumption and small area overhead. Measurement results on a 32-bit pipelined adder chain fabricated with 0.18 μ m CMOS technology show that the proposed approach can achieve a significant reduction in power-delay product (PDP) down to 5 fJ/stage.

Original languageEnglish (US)
Pages (from-to)973-978
Number of pages6
JournalMicroelectronics Journal
Issue number6
StatePublished - Jun 1 2009



  • CMOS integrated circuits
  • Current-mode logic (CML)
  • Pipelined SCL
  • Source-coupled logic (SCL)
  • Subthreshold SCL (STSCL)
  • Ultra-low power circuit design

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Electrical and Electronic Engineering

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