A novel efficient coplanar QCA full adder and full subtractor design

Abstract

ABSTRACT Quantum-dot Cellular Automata (QCA) nanotechnology is an alternative technology with high speed, high density and low power for designing nanoscale circuits. A novel design of Full Adder-Subtractor based on full subtractor using single layer is proposed. The proposed architecture has a major advantage in terms of complexity, area, latency, and power consumption as compared to previous designs. The proposed QCA full subtractor showed higher performance concerning area with a reduction of 66%, and complexity with a reduction of 51% over best existing circuit designs. However, the proposed design of full Adder-Subtractor achieved a reduction of 74% in area, with 70% improvement in complexity, 33% reduction in latency by using two clock phases, and 95% improvement in cost needed over the best reported circuits using single-layer design. Total cell area and cost for the Full Adder-Subtractor were 0.01 μm2 and 0.07, respectively. Results showed that power consumption for the novel design was minimal. Therefore, the suggested Full Adder-Subtractor provides 86% less total energy consumption for 0.5Ek tunnelling energy level. These designs were tested and simulated using the freely known QCA Designer tool version 2.0.3. The energy dissipation result was realised by using the QCAPro energy estimation tool.