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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.
1

A Wide Band Adaptive All Digital Phase Locked Loop With Self Jitter Measurement And Calibration

Jiang, Bo 01 January 2016 (has links)
The expanding growth of mobile products and services has led to various wireless communication standards that employ different spectrum bands and protocols to provide data, voice or video communication services. Software deffned radio and cognitive radio are emerging techniques that can dynamically integrate various standards to provide seamless global coverage, including global roaming across geographical regions, and interfacing with different wireless networks. In software deffned radio and cognitive radio, one of the most critical RF blocks that need to exhibit frequency agility is the phase lock loop (PLL) frequency synthesizer. In order to access various standards, the frequency synthesizer needs to have wide frequency tuning range, fast tuning speed, and low phase noise and frequency spur. The traditional analog charge pump frequency synthesizer circuit design is becoming diffcult due to the continuous down-scalings of transistor feature size and power supply voltage. The goal of this project was to develop an all digital phase locked loop (ADPLL) as the alternative solution technique in RF transceivers by taking advantage of digital circuitry's characteristic features of good scalability, robustness against process variation and high noise margin. The targeted frequency bands for our ADPLL design included 880MHz-960MHz, 1.92GHz-2.17GHz, 2.3GHz-2.7GHz, 3.3GHz-3.8GHz and 5.15GHz-5.85GHz that are used by wireless communication standards such as GSM, UMTS, bluetooth, WiMAX and Wi-Fi etc. This project started with the system level model development for characterizing ADPLL phase noise, fractional spur and locking speed. Then an on-chip jitter detector and parameter adapter was designed for ADPLL to perform self-tuning and self-calibration to accomplish high frequency purity and fast frequency locking in each frequency band. A novel wide band DCO is presented for multi-band wireless application. The proposed wide band adaptive ADPLL was implemented in the IBM 0.13µm CMOS technology. The phase noise performance, the frequency locking speed as well as the tuning range of the digitally controlled oscillator was assessed and agrees well with the theoretical analysis.
2

Etude des couplages substrats dans des circuits mixtes "Smart Power" pour applications automobiles / Substrate coupling study in Smart Power Mixed ICs for automotive application

Thomas tomasevic, Marc veljko 27 February 2017 (has links)
Les circuits Smart Power, utilisés dans l’industrie automobile, se caractérisent par l’intégration sur une puce des parties de puissance avec des parties analogiques&numériques basse tension. Leur principal point faible vient de la commutation des structures de puissance sur des charges inductives. Celles-ci injectent des courants parasites dans le substrat, pouvant activer des structures bipolaires parasites inhérentes au layout du circuit, menant à une défaillance ou la destruction du circuit intégré.Ces structures parasites ne sont pas actuellement modélisées dans les outils CAO ni simulées par les simulateurs de type SPICE. L'extraction de ces structures à partir du layout et leur intégration dans les outils CAO est l’objectif du projet européen AUTOMICS, dans le cadre duquel cette thèse a été réalisée.La caractérisation du couplage substrat sur deux cas d’études a permis de valider les modèles théoriques et de les comparer aux simulations utilisant le nouveau modèle de couplage substrat. / Smart Power circuits, used in the automotive industry, are characterized by the integration on one chip of the power parts with low voltage analog and digital parts. Their main weak point comes from the switching of power structures on inductive loads. These inject parasitic currents in the substrate, capable of activating the bipolar parasitic structures inherent in the layout of the circuit, leading to failure or destruction of the integrated circuit.These parasitic structures are not currently integrated into CAD tools nor simulated by SPICE simulators. The extraction of these structures from the layout and their integration into the CAD tools is the objective of the European AUTOMICS project, in which this thesis is carried out.The characterization of the substrate coupling of 2 case study was used to validate theoretical models and compare them to simulations using the new substrate coupling model.
3

Random Local Delay Variability : On-chip Measurement And Modeling

Das, Bishnu Prasad 06 1900 (has links)
This thesis focuses on random local delay variability measurement and its modeling. It explains a circuit technique to measure the individual logic gate delay in silicon to study within-die variation. It also suggests a Process, Voltage and Temperature (PVT)-aware gate delay model for voltage and temperature scalable linear Statistical Static Timing Analysis (SSTA). Technology scaling allows packing billions of transistors inside a single chip. However, it is difficult to fabricate very small transistor with deterministic characteristic which leads to variations. Transistor level random local variations are growing rapidly in each technology generation. However, there is requirement of quantification of variation in silicon. We propose an all-digital circuit technique to measure the on-chip delay of an individual logic gate (both inverting and non-inverting) in its unmodified form based on a reconfigurable ring oscillator structure. A test chip is fabricated in 65nm technology node to show the feasibility of the technique. Delay measurements of different nominally identical inverters in close physical proximity show variations of up to 28% indicating the large impact of local variations. The huge random delay variation in silicon motivates the inclusion of random local process parameters in delay model. In today’s low power design with multiple supply domain leads to non-uniform supply profile. The switching activity across the chip is not uniform which leads to variation of temperature. Accurate timing prediction motivates the necessity of Process, Voltage and Temperature (PVT) aware delay model. We use neural networks, which are well known for their ability to approximate any arbitrary continuous function. We show how the model can be used to derive sensitivities required for voltage and temperature scalable linear SSTA for an arbitrary voltage and temperature point. Using the voltage and temperature scalable linear SSTA on ISCAS 85 benchmark shows promising results with average error in mean delay is less than 1.08% and average error in standard deviation is less than 2.65% and errors in predicting the 99% and 1% probability point are 1.31% and 1% respectively with respect to SPICE.
4

NOVÉ PRINCIPY CHARAKTERIZACE HRADLOVÝCH KAPACIT PRO SIGMA-DELTA MODULÁTORY / NEW PRINCIPLES OF GATE CAPACITANCE CHARACTERIZATION FOR SIGMA-DELTA MODULATORS

Sutorý, Tomáš January 2009 (has links)
This thesis deals with the utilization of new principles of characterization of gate capacitances for sigma-delta modulators. Sigma-delta modulators are the integral part of sigma-delta analog-to-digital converters. The proposed new method is characterized by high resolution and modest requirements for laboratory equipment. It allows characterizing capacitances whose values are within the range which is used in sigma-delta modulators. The thesis contains description of the new method, the analysis of measurement accuracy and experimental results.

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