An unbalanced ternary multiplier cell based on graphene nanoribbon field-effect transistors for PVT-tolerant low-energy portable applications

Abstract

The potential benefits of using multiple-valued logic (MVL), especially ternary logic, which includes less interconnections, quicker response times, and smaller chip sizes, has gained the interest of designers of digital systems. A practical solution for achieving circuits with multiple thresholds in an efficient manner is through using graphene nanoribbon field-effect transistors (GNRFETs) that have modifiable threshold voltage values by adjusting the width of graphene nanoribbon. This article leverages the unique characteristics of GNRFETs and proposes a new design for a single-trit ternary multiplier (TMUL) circuit. The proposed TMUL uses two supply voltages to block direct current paths from high-to-low voltage levels, resulting in power and energy savings. Additionally, unary operators such as negative and positive ternary inverters and the complement of decisive literal are used to reduce transistor count and improve circuit performance. To thoroughly evaluate the performance of the proposed GNRFET-based TMUL circuit, extensive simulations are performed using Synopsis HSPICE tool and 32-nm channel length GNRFET devices, while taking into account the influences of process-voltage-temperature variations (PVT). The simulation results confirm the robustness and reliability of the proposed design, exhibiting reductions in power consumption by 71.18% to 76.36%, and energy consumption by 67.78% to 86.54%, when compared to other state-of-the-art TMUL circuits available in literature. Moreover, Monte-Carlo simulations have been performed to demonstrate that the suggested design exhibits reduced sensitivity towards significant process variations. As a result, the presented TMUL design can be a good choice for use in low-energy battery-operated portable multimedia device.