This paper first presents an efficient quantum-dot cellular automata (QCA) design for the Ladner-Fischer prefix adder. We then present an efficient QCA design of a hybrid adder that combines the Ladner-Fischer adder with a ripple carry adder. We show that the hybrid adder has better performance (in terms of latency) in QCA than a Ladner-Fischer or a ripple carry adder. We also show that the hybrid adder has a smaller area-delay product than existing adder designs in QCA. Results of simulation in QCADesigner are also given and they support the theory presented. © 2010 IEEE.

Krishnamurthy Sridharan

Department of Electrical Engineering

ADDER DESIGN

Efficient designs

HYBRID ADDER

LADNER-FISCHER ADDER

PREFIX ADDERS

QUANTUM-DOT CELLULAR AUTOMATA

RIPPLE CARRY ADDERS

Cellular automata

Design

Pattern recognition systems

Quantum efficiency

Semiconductor quantum dots

Sequential machines

Adders

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Efficient Design of a Hybrid Adder in Quantum-Dot Cellular Automata

IEEE Transactions on Very Large Scale Integration (VLSI) Systems

The design of adders on quantum dot cellular automata (QCA) has been of recent interest. While few designs exist, investigations on reduction of QCA primitives (majority gates and inverters) for various adders are limited. In this paper, we present a number of new results on majority logic. We use these results to present efficient QCA designs for the ripple carry adder (RCA) and various prefix adders. We derive bounds on the number of majority gates for n-bit RCA and n-bit rent-Kung, Kogge-Stone, Ladner-Fischer, and Han-Carlson adders. We further show that the Brent-Kung adder has lower delay than the best existing adder designs as well as other prefix adders. In addition, signal integrity and robustness studies show that the proposed Brent-Kung adder is fairly well-suited to changes in time-related parameters as well as temperature. Detailed simulations using QCADesigner are presented. © 2011 IEEE.

IEEE Transactions on Nanotechnology

Low complexity design of ripple carry and brent-kung adders in QCA

Computer Arithmetic Algorithms

IEEE Transactions on Computers

Adder and Multiplier Design in Quantum-Dot Cellular Automata

Analyzing the Inherent Reliability of Moderately Sized Magnetic and Electrostatic QCA Circuits Via Probabilistic Transfer Matrices

Estimation of Upper Bound of Power Dissipation in QCA Circuits

22nd IEEE International Symposium on Defect and Fault-Tolerance in VLSI Systems (DFT 2007)

Probabilistic Analysis of a Molecular Quantum-Dot Cellular Automata Adder

Efficient design of a hybrid adder in quantum-dot cellular automata

Journal	IEEE Transactions on Very Large Scale Integration (VLSI) Systems
ISSN	10638210
Open Access	No