Design and Demonstration of MEM Relay-Based Arithmetic and Sequential Circuit Blocks

Ren Li,Hossein Fariborzi

doi:10.1109/ted.2021.3118663

Abstract

The Internet of Things (IoT) has become more prevalent in recent years and is an integral part of everyday life. Thus, the need for ultralow-power sensors and processing units has dramatically increased. The continuous scaling of CMOS transistors has resulted in more severe subthreshold leakage and high power density issues. In recent years, microelectromechanical (MEM) relays have attracted research interests. They are viewed as promising beyond-CMOS candidates due to their nonleaking property and abrupt switch ON/OFF characteristics. This article presents the design and characterization of a few core relay-based digital blocks, including an adder and a D-latch. While the mechanical movement of relays makes them inherently slower than transistors, we show that the scaled 32-bit relay adder offers 60 times less energy per operation than its CMOS counterpart in 40-nm technology. This makes the proposed relay circuits particularly appealing to applications with stringent demand on energy efficiency and moderate performance requirements, such as remote sensors, wearable accessories, and implantable biomedical devices.

Highlights

T HE integrated circuits (IC) industry has been dominated by the CMOS technology over the past few decades
The most significant roadblock is related to the exacerbation of the subthreshold leakage, which has brought about high power consumption per unit area of the chip, especially in digital circuits
We present the characterization results of fabricated MEM relays, and for the first time, we study the effect of clock frequency over lifetime and experimentally verify the tuning of the mechanical delay

Summary

Introduction

T HE integrated circuits (IC) industry has been dominated by the CMOS technology over the past few decades. The constant scaling of CMOS transistors, predicted by Moore’s law, has propelled the chip industry toward making ICs with higher device density, performance, and circuit complexity. The most significant roadblock is related to the exacerbation of the subthreshold leakage, which has brought about high power consumption per unit area of the chip, especially in digital circuits. Various designs of microelectromechanical (MEM) relays have been proposed [1]–[6]. Relays have attracted research interests due to their zero subthreshold leakage property [7], [8], steep turn on/off characteristics [9], Manuscript received August 11, 2021; revised September 19, 2021; accepted October 5, 2021.

Methods

Findings

Discussion

Conclusion