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.
MGDI technique, in which a low number of transistors are used to reduce the power consumption and area on chip of digital circuits. In this paper the full adder is introduced using MGDI technique. 2 bit comparator, full subtractor were introduced using GDI technique. Then these digital circuits were compared with traditional CMOS transistors in terms of power dissipation, number of transistors, area, speed and delay.
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.
Understanding highly complex nature of flow in an IC engine is essential to optimize its performance. However, the events like reciprocating motion of piston, motion of valves, turbulence generation, spray and mixing lead to a complex flow pattern. CFD is very useful in computing and understanding this complex flow pattern. In this book, all aspects of CFD technique to simulate the mixing of fuel with air in GDI engines are explained. The book covers the governing equations, numerical techniques for solving them, method of analysis of data (in the context of mixing processes) and programming techniques. The book will be useful for professionals who are performing CFD analysis using CFD softwares for thermal systems specifically reciprocating systems like engines, compressors and systems involving sprays, mixing etc. It is also useful for those who are developing CFD tools.
This book presents design of a low power high speed 1-bit ALU in 45nm CMOS technology. Low power high speed circuit design has emerged as a challenging and an emerging field among circuit designers and researchers. A 1-bit ALU is designed in 45nm CMOS technology by using CMOS, nMOS PTL and GDI circuit techniques and its performance characteristics such as power dissipation, delay, power-delay product and number of transistors are compared. GDI technique provides better performance characteristics for designing a low power high speed VLSI circuit. This circuit technique reduces power dissipation, delay, and it also maintains low complexity in the integrated circuit design. This technique is suitable for designing a low power high speed VLSI circuit by using very less number of transistors as compared to other circuit design techniques. This technique has emerged as an effective circuit technique for designing a low power high speed VLSI circuit. The contributions made in this book would help circuit designers and researchers in designing low power high speed integrated circuits.
The Direct-Injection (DI) combined with downsizing, variable valve timing and turbocharging promises a strong reduction of fuel consumption for Spark-Ignition (SI) engines. The advantages of DI have been widely demonstrated in terms of fuel economy, transient response, air-to-fuel ratio (AFR) control and reduced emissions. The control of fuel spray and air-fuel mixture formation is fundamental for fully taking advantages of DI in SI engines. This work investigates the influence of injection parameters on air/fuel mixture and combustion processes in a DISI engine. In the first part the main fuel spray parameters were investigated: Particle Image Velocimetry allowed to characterize the spray velocity field while Phase Doppler Anemometry was applied for droplets size and velocity measurements. An innovative X-ray tomography technique allowed to investigate the inner structure of the fuel spray in the region immediately downstream of the nozzle. Finally, the effect of the injection duration and phasing on the combustion process and pollutant emissions formation was studied in a GDI optically accessible engine, through UV-visible imaging and spectroscopy.