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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Prospects for Mirror-Enabled Polymer Pillar I/O Optical Interconnects for Gigascale Integration

Ogunsola, Oluwafemi Olusegun 27 October 2006 (has links)
Digital systems have derived performance benefits due to the scaling down of CMOS microprocessor feature sizes towards packing billions of transistors on a chip, or gigascale integration (GSI). This has placed immense bandwidth demands on chip-to-chip and chip-to-board interconnects. The present-day electrical interconnect may limit bandwidth as transmission rates grow. As such, optical interconnects have been proposed as a potential solution. A critical requirement for enabling chip-to-chip and chip-to-board optical interconnection is out-of-plane coupling for directing light between a chip and the board. Any solution for this problem must be compatible with conventional packaging and assembly requirements. This research addresses the prospects for integrating waveguides with mirrors and polymer pillar optical I/O interconnects to provide such a compatible, out-of-plane, chip-to-board packaging solution through the design, analysis, fabrication, and testing of its constituent parts and their ultimate integration.
72

Flicker noise in cmos lc oscillators

Douglas, Dale Scott 10 November 2008 (has links)
Sources of flicker noise generation in the cross-coupled negative resistance oscillator (NMOS, PMOS, and CMOS) are explored. Also, prior and current work in the area of phase noise modeling is reviewed, including the work of Leeson, Hajimiri, Hegazi, and others, seeking the mechanisms by which flicker noise is upconverted. A Figure of Merit (FOM) methodology suitable to the 1/f3 phase noise region is also developed, which allows a new quantity, FOM1, to be defined. FOM1 is proportional to flicker noise upconverted, thus allowing the effectiveness of flicker noise upconversion suppression techniques to be evaluated, despite possibly changing bias points or tank Q, which would change phase noise and FOM in the 1/f2 region. The work of Hajimiri is extended with a simple Amplitude ISF DC component estimator for the special case of LC CMOS oscillators. A method of adaptive control of an oscillator core is presented, as well, comprised of a CMOS oscillator with a digitally adjustable N and P width, and a circuit (which is essentially a tracking ADC) which repeatedly adjusts the relative N to P width dependent on the estimate to maintain the condition of minimum flicker noise upconversion. A fixed calibration constant is sufficient to allow convergence to within 0.7dB of optimal FOM1 for all cases of N width, for a varactorless oscillator test cell. Finally, a circuit is proposed which would allow the flicker noise reduction technique of cycling to accumulation to be applied to continuous time oscillators, but is not rigorously vetted.
73

Improving Digital Circuit Simulation: A Knowledge-Based Approach

Benavides, John A. (John Anthony) 08 1900 (has links)
This project focuses on a prototype system architecture which integrates features of an event-driven gate-level simulator and features of the multiple expert system architecture, HEARSAY-II. Combining artificial intelligence and simulation techniques, a knowledge-based simulator was designed and constructed to model non-standard circuit behavior. This non-standard circuit behavior is amplified by advances in integrated circuit technology. Currently available digital circuit simulators can not simulate this behavior. Circuit designer expertise on behavioral phenomena is used in the expert system to guide the base simulator by manipulating its events to achieve the desired behavior.
74

Uma arquitetura de processamento paralelo para implementação de um trigger nível zero para instrumentação nuclear / A parallel processing architecture for the implementation of a level zero trigger for nuclear instrumentation

Guimarães, Homero Luz 22 August 2018 (has links)
Orientador: José Antonio Siqueira Dias / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-22T02:05:02Z (GMT). No. of bitstreams: 1 Guimaraes_HomeroLuz_D.pdf: 8320554 bytes, checksum: cbec86ea8c9ee3ad275baa5f37860192 (MD5) Previous issue date: 2013 / Resumo: Os experimentos em Física de alta energia tem se beneficiado enormemente do progresso alcançado na área de Microeletrônica, pois isto tem proporcionado a criação de detectores mais acurados e circuitos de processamento de sinais analógico/digitais cada vez mais rápidos e precisos. A redução no comprimento mínimo de canal dos processos CMOS além de proporcionar maior velocidade e precisão também reduz a área usada por cada canal, o que permite a implementação de mais canais numa mesma pastilha. Com um numero maior de canais por pastilha, com um mesmo numero de chips podemos programar um numero maior de canais do que anteriormente possível e com isso os físicos podem realizar uma reconstrução da trajetória de maneira mais precisa. Este Trabalho descreve uma proposta para o Trigger de nível zero baseando-se nas especificações disponíveis do Experimento Dzero no Fermi National Accelerator Laboraty (FERMILAB). Este trabalho descreve o projeto e implementação de um front-end analógico que detecta a carga provida pelo VLPC (detector luminoso usado no Dzero) seguida por um comparador de alta velocidade que fornece um nível lógico para um processador digital. O processador digital por sua vez usa uma arquitetura de processadores paralelos que, comunicando-se entre si são capazes de estimar a trajetória de partículas baseando-se em dados inicias programados a partir de simulações do detector feitas em computadores pelos Físicos. Tanto o bloco analógico quanto o processador digital foram implementados usando-se o processo CMOS90 da IBM / Abstract: The experiments in high-energy physics has benefited greatly from the progress made in the area of Microelectronics, since it has provided the creation of more accurate detectors and analog / digital signal processing circuits that are increasingly fast and accurate. The reduction in the minimum length of the channel in modern CMOS processes while providing greater speed and precision also reduces the area used by each channel, which enables the implementation of more channels on the same chip. With a larger number of channels per chip, we can with the same number of chips implement a larger number of channels than previously possible and with that physicists can perform a reconstruction of the trajectory more accurately. This work describes a proposal for a Trigger level zero based on the available specifications of the DZero experiment at the Fermi National Accelerator Laboraty (FERMILAB). In the following pages the design and implementation of an analog front-end that detects the charge provided by the VLPC detector followed by a high-speed comparator that provides a logical level to a digital processor are described. The digital processor in turn uses an architecture of parallel processors that communicate with each other are able in order to estimate the trajectory of particles based on initial data loaded in RAM based on simulations of the detector geometry made by physicists. Both the analog block and the digital processor are implemented using the IBM CMOS90 process / Doutorado / Eletrônica, Microeletrônica e Optoeletrônica / Doutor em Engenharia Elétrica
75

Multi-processor logic simulation at the chip level

Roumeliotis, Emmanuel January 1986 (has links)
This dissertation presents the design and development of a multi-processor logic simulator. After an introduction to parallel processing, the concept of distributed simulation is described as well as the possibility of deadlock in a distributed system. It is proven that the proposed system does not deadlock. Next, the modeling techniques are discussed along with the timing mechanisms used for logic simulation. A new approach, namely process oriented simulation is studied in depth. It is shown that modeling for this kind of simulation is more efficient regarding modeling ease, computer memory and simulation time, than existing simulation methods. The hardware design of the multi-processor system and the algorithms for synchronization and signal interchange between the processors are presented next. An algorithm for an efficient partitioning of the digital network to be simulated among the processors of the system is also described. Apart from the simulation of a single digital network, the simulator can also be used for fault simulation and design verification. Regarding fault simulation, the fault injection and fault detection techniques are presented. The experimental results obtained by running the multi-processor simulator are compared with the theoretical estimates as well as with results obtained by other multi-processor systems. The comparison shows that the proposed simulator exhibits the estimated performance. Finally, the design of a common bus interface is given. This interface will connect the processors of the system directly without the intervention of a hard disk which was used for the development and testing of the system. / Ph. D.
76

An Interactive Framework for Teaching Fundamentals of Digital Logic Design and VLSI Design

Battina, Brahmasree 08 1900 (has links)
Integrated Circuits (ICs) have a broad range of applications in healthcare, military, consumer electronics etc. The acronym VLSI stands for Very Large Scale Integration and is a process of making ICs by placing millions of transistors on a single chip. Because of advancements in VLSI design technologies, ICs are getting smaller, faster in speed and more efficient, making personal devices handy, and with more features. In this thesis work an interactive framework is designed in which the fundamental concepts of digital logic design and VLSI design such as logic gates, MOS transistors, combinational and sequential logic circuits, and memory are presented in a simple, interactive and user friendly way to create interest in students towards engineering fields, especially Electrical Engineering and Computer Engineering. Most of the concepts are explained in this framework by taking the examples which we see in our daily lives. Some of the critical design concerns such as power and performance are presented in an interactive way to make sure that students can understand these significant concepts in an easy and user friendly way.
77

Projeto de circuito oscilador controlado numericamente implementado em CMOS com otimização de área. / Design of a circuit numerically controlled oscilator implemented in CMOS with area optimization.

Carvalho, Paulo Roberto Bueno de 25 October 2016 (has links)
Este trabalho consiste no projeto e implementação em CMOS de um circuito integrado digital para geração de sinais, denominado Oscilador Controlado Numericamente. O circuito será aplicado em um sistema de Espectroscopia por Bioimpedância Elétrica, utilizado como método para detecção precoce de câncer do colo do útero. Durante o trabalho, realizou-se o estudo dos requisitos do sistema de espectroscopia e as especificações dos tipos de sinais a serem gerados. Levantou-se, na bibliografia, algumas técnicas de codificação em linguagem de hardware para otimização do projeto nos quesitos área, potência dissipada e frequência máxima de funcionamento. Para implementar o circuito, também se pesquisou o fluxo de projeto de circuitos digitais, focando as etapas de codificação em linguagem de descrição de hardware Verilog e os resultados de síntese lógica e de layout. Foram avaliadas duas arquiteturas, empregando-se algumas das técnicas de codificação levantadas durante o estudo bibliográfico. Estas arquiteturas foram implementadas, verificadas em plataforma programável, sintetizadas e mapeadas em portas lógicas no processo TSMC 180 nm, onde foram comparados os resultados de área e dissipação de potência. Observou-se, nos resultados de síntese lógica, redução de área de 78% e redução de 83% na dissipação de potência total no circuito em que se aplicou uma das técnicas de otimização em comparação com o circuito implementado sem otimização, utilizando uma arquitetura CORDIC do tipo unrolled. A arquitetura com menor área utilizada - 0,017 mm2 - foi escolhida para fabricação em processo mapeado. Após fabricação e encapsulamento do circuito, o chip foi montado em uma placa de testes desenvolvida para avaliar os resultados qualitativos. Os resultados dos testes foram analisados e comparados aos obtidos em simulação, comprovando-se o funcionamento do circuito. Observou-se uma variação máxima de 0,00623% entre o valor da frequência do sinal de saída obtido nas simulações e o do circuito fabricado. / The aim of this work is the design of a digital integrated circuit for signal generation called Numerically Controlled Oscillator, designed in 180 nm CMOS technology. The application target is for Electrical Bioimpedance Spectroscopy system, and can be used as a method for early detection of cervical cancer. Throughout the work, the spectroscopy system requirements and specifications of the types of signals to be generated were studied. Furthermore, the research of some coding techniques in hardware language for design optimization in terms of area, power consumption and frequency operation was conducted looking into the bibliography. The digital design flow was studied focusing on the Verilog hardware description language and the results of logic synthesis and layout, in order to implement the circuit. Reviews of two architectures have been made, using some of the encoding techniques that have been raised during the bibliographical study. These architectures have been implemented, verified on programmable platform, synthesized and mapped to standard cells in TSMC 180 nm process, which compared the area and total power consumption of results. Based on the results of logic synthesis, a 78% area reduction and 83% power consumption reduction were obtained on the implemented circuit with encoding techniques for optimization in comparison with the another circuit using a CORDIC unrolled architecture. The architecture with smaller area - 0.017 mm2 - was chosen for implementation in the mapped process. After the circuit fabrication and packaging, the chip was mounted on an evaluation board designed to evaluate the functionality. The test results were analyzed and compared with the simulation results, showing that the circuit works as expected. The output signals were compared between theoretical and experimental results, showing a maximum deviation of 0.00623%.
78

Projeto de circuito oscilador controlado numericamente implementado em CMOS com otimização de área. / Design of a circuit numerically controlled oscilator implemented in CMOS with area optimization.

Paulo Roberto Bueno de Carvalho 25 October 2016 (has links)
Este trabalho consiste no projeto e implementação em CMOS de um circuito integrado digital para geração de sinais, denominado Oscilador Controlado Numericamente. O circuito será aplicado em um sistema de Espectroscopia por Bioimpedância Elétrica, utilizado como método para detecção precoce de câncer do colo do útero. Durante o trabalho, realizou-se o estudo dos requisitos do sistema de espectroscopia e as especificações dos tipos de sinais a serem gerados. Levantou-se, na bibliografia, algumas técnicas de codificação em linguagem de hardware para otimização do projeto nos quesitos área, potência dissipada e frequência máxima de funcionamento. Para implementar o circuito, também se pesquisou o fluxo de projeto de circuitos digitais, focando as etapas de codificação em linguagem de descrição de hardware Verilog e os resultados de síntese lógica e de layout. Foram avaliadas duas arquiteturas, empregando-se algumas das técnicas de codificação levantadas durante o estudo bibliográfico. Estas arquiteturas foram implementadas, verificadas em plataforma programável, sintetizadas e mapeadas em portas lógicas no processo TSMC 180 nm, onde foram comparados os resultados de área e dissipação de potência. Observou-se, nos resultados de síntese lógica, redução de área de 78% e redução de 83% na dissipação de potência total no circuito em que se aplicou uma das técnicas de otimização em comparação com o circuito implementado sem otimização, utilizando uma arquitetura CORDIC do tipo unrolled. A arquitetura com menor área utilizada - 0,017 mm2 - foi escolhida para fabricação em processo mapeado. Após fabricação e encapsulamento do circuito, o chip foi montado em uma placa de testes desenvolvida para avaliar os resultados qualitativos. Os resultados dos testes foram analisados e comparados aos obtidos em simulação, comprovando-se o funcionamento do circuito. Observou-se uma variação máxima de 0,00623% entre o valor da frequência do sinal de saída obtido nas simulações e o do circuito fabricado. / The aim of this work is the design of a digital integrated circuit for signal generation called Numerically Controlled Oscillator, designed in 180 nm CMOS technology. The application target is for Electrical Bioimpedance Spectroscopy system, and can be used as a method for early detection of cervical cancer. Throughout the work, the spectroscopy system requirements and specifications of the types of signals to be generated were studied. Furthermore, the research of some coding techniques in hardware language for design optimization in terms of area, power consumption and frequency operation was conducted looking into the bibliography. The digital design flow was studied focusing on the Verilog hardware description language and the results of logic synthesis and layout, in order to implement the circuit. Reviews of two architectures have been made, using some of the encoding techniques that have been raised during the bibliographical study. These architectures have been implemented, verified on programmable platform, synthesized and mapped to standard cells in TSMC 180 nm process, which compared the area and total power consumption of results. Based on the results of logic synthesis, a 78% area reduction and 83% power consumption reduction were obtained on the implemented circuit with encoding techniques for optimization in comparison with the another circuit using a CORDIC unrolled architecture. The architecture with smaller area - 0.017 mm2 - was chosen for implementation in the mapped process. After the circuit fabrication and packaging, the chip was mounted on an evaluation board designed to evaluate the functionality. The test results were analyzed and compared with the simulation results, showing that the circuit works as expected. The output signals were compared between theoretical and experimental results, showing a maximum deviation of 0.00623%.
79

Variability Aware Device Modeling and Circuit Design in 45nm Analog CMOS Technology

Ajayan, K R January 2014 (has links) (PDF)
Process variability is a major challenge for the design of nano scale MOSFETs due to fundamental physical limits as well as process control limitations. As the size of the devices is scales down to improve performance, the circuit becomes more sensitive to the process variations. Thus, it is necessary to have a device model that can predict the variations of device characteristics. Statistical modeling method is a potential solution for this problem. The novelty of the work is that we connect BSIM parameters directly to the underlying process parameters. This is very useful for fabs to optimize and control the specific processes to achieve certain circuit metric. This methodology and framework is extendable to any future technologies, because we used a device independent, but process depended frame work In the first part of this thesis, presents the design of nominal MOS devices with 28 nm physical gate length. The device is optimized to meet the specification of low standby power technology specification of International Technology Roadmap for Semiconductors ITRS(2012). Design of experiments are conducted and the following parameters gate length, oxide thickness, halo concentration, anneal temperature and title angle of halo doping are identified as the critical process parameters. The device performance factors saturation current, sub threshold current, output impendence and transconductance are examined under process variabilty. In the subsequent sections of the thesis, BSIM parameter extraction of MOS devices using the software ICCAP is presented. The variability of the spice parameters due to process variation is extracted. Using the extracted data a new BSIM interpolated model for a variability aware circuit design is proposed assume a single process parameter is varying. The model validation is done and error in ICCAP extraction method for process variability is less than 10% for all process variation condition in 3σ range. In the next section, proposes LUT model and interpolated method for a variability aware circuit design for single parameter variation. The error in LUT method for process variability reports less than 3% for all process variation condition in 3σ range. The error in perdition of drain current and intrinsic gain for LUT model files are very close to the result of device simulation. The focus of the work was to established effective method to interlink process and SPICE parameters under variability. This required generating a large number of BSIM parameter ducks. Since there could be some inaccuracy in large set of BSIM parameters, we used LUT as a golden standard. We used LUT modeling as a benchmark for validation of our BSIM3 model In the final section of thesis, impact of multi parameter variation of the processes in device performance is modelled using RSM method; the model is verified using ANOVA method. Models are found to be sufficient and stable. The reported error is less than 1% in all cases. Monte Carlo simulation confirms stability and repeatability of the model. The model for random variabilty of process parameters are formulated using BSIM and compared with the LUT model. The model was tested using a benchmark circuit. The maximum error in Monte Carlo simulation is found to be less than 3% for output current and less than 8% for output impedance.

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