This book introduces a Gate Diffusion Input (GDI) methodology as an alternative approach in digital circuits. In this technique, a wide range of complex logic functions can be realized by using a lower number of CMOS transistors. The advantages of using GDI technique are multi-folded. The first is to implement digital gates (i.e. inverters, NAND, NOR, XOR, XNOR, buffers, etc.) with very low propagation delay and high logic level swing. As a second advantage, the GDI-based circuits consume lower power consumption and chip area compared with the CMOS equivalent. This provides a new implementation of digital circuits which are suitable for longer-lasting portable devices, like smartphones, tablets, IoT, etc.. A third advantage is the simplicity of circuit design by using very small cell library. In this book, after a brief review of GDI specifications, we will discuss different architectures of GDI-based digital circuits that have been recently proposed.
In this thesis work, a new technique for designing logic circuits called the Modified Gate Diffusion Input (MGDI) logic is discussed. This logic is adopted from the Gate Diffusion Input (GDI) technique. GDI was first proposed in the year 2002 for solving the problems associated with different CMOS logic styles. GDI cell can be used to implement wide variety of complex logic functions using only two transistors. GDI technique allows design of high speed and low power circuits with reduced number of transistors as compared to static CMOS and Pass Transistor Logic (PTL) techniques. This work aims to design a various high performance adders and multipliers.
As technology scales into the nanometer regime leakage current, active power, delay and area are the important metric for the analysis and design of complex arithmetic logic circuits. In this paper, low leakage 1bit full adder cell are proposed for mobile applications and a novel technique has been introduced with improved staggered phase damping technique and also Gated Diffusion Input (GDI) technique for further reduction in the Active power. Leakage power is being estimated when the circuits are connected with a sleep transistor, Further compared to the Base case and Design1 and Design2 and GDI Technique when a circuit is connected to sleep transistor. We introduced a new transistor resizing approach for 1bit full adder cells to determine the optimal sleep transistor size which reduce the leakage power and Area. The simulation results depicts that the proposed design also leads to efficient 1bit full adder cells in terms of standby leakage power, active power. We have performed simulations using Microwind 90nm standard CMOS technology at room temperature with supply voltage of 1V.
Stringent emission regulations aim to restrict soot emissions by particle mass and particle number in the transport sector. Whilst the concept of direct-injection gasoline (GDI) engines is very promising with respect to efficiency, complying with the legislative soot emission limits is challenging for GDI-engines. A sufficient reduction of soot emissions in GDI engines requires a detailed understanding and accurate modeling of soot formation processes of gasoline fuels in engines. This study provides fundamental investigations of the soot formation process of common gasoline surrogate components.Soot volume fraction profiles in laminar counterflow flames burning ethylene, n-heptane, iso-octane, and toluene were determined experimentally for a wide range of flame conditions. Simulations of these flames reveal that applied models are capable of predicting the soot volume fraction with remarkable accuracy for ethylene. For the gasoline surrogate components, however, the overall soot volume fractions are overpredicted. Reaction pathway analysis suggests that, in these flames, more soot precursors are formed via the reaction pathways involving fuel pyrolysis products.Furthermore, flame structure, local gas temperature, local soot volume fraction, and primary soot particle diameter were simultaneously detected by means of optical diagnostics in turbulent toluene flames. Joint statistics of flame and soot properties indicate that, due to differential diffusion of soot, high soot concentrations are present at conditions of low temperatures and low OH concentrations. In the soot oxidation region, the presence of large particles suggest that the oxidation is not sufficiently fast to burn soot completely.