Table of Contents
VLSI Design
Volume 2012, Article ID 173079, 18 pages
Research Article

Performance Analysis of High Speed Hybrid CMOS Full Adder Circuits for Low Voltage VLSI Design

1Department of Electronics Engineering, Institute of Engineering & Technology (IET), Lucknow 226021, India
2Department of Electronics and Communication Engineering, Motilal Nehru National Institute of Technology (MNNIT), Allahabad 211004, India

Received 28 June 2011; Revised 2 November 2011; Accepted 24 November 2011

Academic Editor: Jose Carlos Monteiro

Copyright © 2012 Subodh Wairya et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This paper presents a comparative study of high-speed and low-voltage full adder circuits. Our approach is based on hybrid design full adder circuits combined in a single unit. A high performance adder cell using an XOR-XNOR (3T) design style is discussed. This paper also discusses a high-speed conventional full adder design combined with MOSCAP Majority function circuit in one unit to implement a hybrid full adder circuit. Moreover, it presents low-power Majority-function-based 1-bit full addersthat use MOS capacitors (MOSCAP) in its structure. This technique helps in reducing power consumption, propagation delay, and area of digital circuits while maintaining low complexity of logic design. Simulation results illustrate the superiority of the designed adder circuits over the conventional CMOS, TG, and hybrid adder circuits in terms of power, delay, power delay product (PDP), and energy delay product (EDP). Postlayout simulation results illustrate the superiority of the newly designed majority adder circuits against the reported conventional adder circuits. The design is implemented on UMC 0.18  𝜇 m process models in Cadence Virtuoso Schematic Composer at 1.8 V single-ended supply voltage, and simulations are carried out on Spectre S.