A compact design of n-bit ripple carry adder circuit using QCA architecture

Abstract

In this paper, we propose a new 3-dot based QCA architecture. We also present wiring logics, basic gates and XOR gate using proposed QCA 3-dot cell. All these components are very much efficient to compute basic operations. Moreover, we design a QCA 3-dot based half adder and extend the half adder into a full adder which has least number of QCA cells till now. We also design a powerful and efficient n-bit ripple carry adder applying our new and novel scheme. Our proposed circuits perform much better than the existing ones, e.g., the proposed 32-bit ripple carry adder circuit improves 21 % on QCA cell, 99% on area than the exist i ng best known one.

An efficient design of adder/subtractor circuit using quantum dot cellular automata

“…A QCA 3-dot cell which is built by three quantum dots and are designed in a scalene triangle [5]. The dots are referred by a 1 , a 2 , a 3 [5]. The three sides are not in same size.…”

“…The three sides are not in same size. They are arranged like a 2 a 3 > a 1 a 2 > a 1 a 3 [5]. The cell can also rotate in 90 degree, 180 degree and 270 degree [5].…”

“…They are arranged like a 2 a 3 > a 1 a 2 > a 1 a 3 [5]. The cell can also rotate in 90 degree, 180 degree and 270 degree [5]. Binary value of the QCA 3-dot based cell depends on the polarization and columbic force of a single cell [5].…”

“…The area of a cell is reduced if the working temperature is rise. For this reason, the area of a single QCA cell is considered as 2 nm with QCADesigner [5,6,7,15]. So the area of a 3-dot based full adder is 3.12 × 10 −5 μm 2 shown in Fig.…”

“…QCA logical circuits mainly depends on QCA cell. We have seen QCA 3-dot based logical devices which are very effective for QCA logical circuit design [5].…”