Design and Comparative Analysis of Half and Full Adders Using CMOS and Pass Transistor Logic Styles

Also Available Domains Transistor Logic|Low Power VLSI

Project Code :TVMABE358

Objective

The objective of this project is to design half and full adder circuits using CMOS and Pass Transistor Logic (PTL) styles and perform a comparative analysis of their performance. It focuses on evaluating key parameters such as propagation delay, power consumption, transistor count, and circuit area for both logic styles. The designs will be simulated and verified to ensure functional correctness and to accurately measure performance metrics. Comparative analysis will highlight the advantages and trade-offs of CMOS and PTL implementations in arithmetic circuit design. The overall goal is to identify the most efficient and reliable adder design suitable for high-performance digital applications.

Abstract

This project presents the design and comparative analysis of half adders and full adders implemented using both conventional CMOS logic and Pass Transistor Logic (PTL) styles. The study focuses on evaluating key performance parameters such as power consumption, propagation delay, transistor count, and overall area efficiency. CMOS adders offer strong noise immunity and reliable operation, while PTL-based designs reduce transistor count and achieve improved speed and lower power by minimizing switching activity and internal node capacitances. By simulating and analyzing both logic styles under identical operating conditions, the project highlights the trade-offs between robustness and efficiency, demonstrating how PTL can significantly enhance performance in low-power and high-speed applications while CMOS remains preferable for designs requiring higher noise margins and full voltage swing outputs.

NOTE: Without the concern of our team, please don't submit to the college. This Abstract varies based on student requirements.

Specifications

· Tool Used: Cadence EDA tools for schematic and simulation

· Technology Node:180nm CMOS process.

· Design Elements: complementary compound push–pull pair (PMOS + NMOS), input matching network, L1 & L2 (0.5 pH–10 pH) inductors, high-value output load (RL, 100 kΩ–1 MΩ), biasing/level-shift network, feedback/compensation path, input/output coupling and decoupling capacitors, thermal-stabilization circuitry, and symmetric/layout considerations for reduced mismatch

· Optimization Goal: minimize circuit complexity and parasitics (transistor and passive count) while preserving ultra-wideband large-signal gain, low output noise, high temperature stability, and linearity across the desired cutoff range (e.g., maintain cutoff from ≈18.21 kHz up to hundreds of GHz in simulation) with low power consumption (~69 mW)v