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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

La Technique des Débits Commutés pour l'évaluation de la dégradation à faible débit de dose des technologies bipolaires en environnement spatial. / The Switched Dose-Rate Technique for an Evaluation of the Degradation at Low Dose Rate of Bipolar Technologies in the Space Environment.

González, Yago 13 December 2010 (has links)
Avant d'approvisionner des lots de composants pour la fabrication de systèmes orbitaux, les grandes agences du spatial (CNES, ESA, NASA, JAXA…) ainsi que les industriels du spatial (EADS, Thales,…) doivent s'assurer de la fiabilité des lots proposés par les fabricants de circuits intégrés. Dans le but d'assurer la fiabilité des composants, des tests sont réalisés suivant des recommandations afin de sélectionner et trier les composants suivant leur tenue à différents modes de défaillance. Parmi tous ces tests, certains sont typiques des applications spatiales : les tests de tenue à la dose. Cette spécificité des tests de tenue à la dose de composants destinés à des applications spatiales est due au fait que l'environnement spatial est un environnement radiatif qui provoque une ionisation dans les matériaux constituant le satellite. Suite à cette ionisation des charges sont créées dans la matière et induisent des modifications au sein des matériaux qui composent les circuits intégrés, ce qui peut provoquer des dérives de leurs caractéristiques électriques. Ces dérives des paramètres électriques en environnement spatial peuvent être perçues comme un vieillissement accéléré des composants électroniques, et des tests sont donc dédiés à prédire et s'assurer du bon fonctionnement des composants même après ce vieillissement accéléré provoqué par la dose. Dans ce travail de thèse nous nous intéressons à l'applicabilité d'une technique de test accéléré des composants bipolaires développée à l'UM2: 'La technique des Débits Commutés'. Une étude de l'effet de la polarisation pendant irradiation a été mené au cours de ce travail de thèse, afin d'appréhender l'impact de la polarisation des composants bipolaires sur les estimations obtenues de façon accélérée grâce à cette technique. / Before supplying lots of components for the manufacture of orbital systems, large space agencies (CNES, ESA, NASA, JAXA ...) and the Industrial Space (EADS, Thales, ...) should ensure the reliability lots offered by manufacturers of integrated circuits. In order to ensure reliability of components, tests are performed following recommendations to select and sort the components according to their resistance to different failure modes. Of all these tests, some are typical for space applications: tests held in the dose. The specificity of the tests held at the dose of components for space applications due to the fact that the environment is a space radiation environment which causes ionization in the materials of the satellite. Following this ionization charges are created in the material and induce changes in the materials that comprise integrated circuits, which can cause drift of their electrical characteristics. These abuses of the electrical parameters in a space environment can be viewed as accelerated aging of electronic components, and tests are dedicated to predict and verify the correct operation of the components even after the accelerated aging caused by dose. In this thesis we investigate the applicability of a technique for accelerated testing of components developed in bipolar UM2: 'The technique of Switched Flows'. A study of the effect of the polarization during irradiation was conducted during this thesis, to understand the impact of the polarization of the bipolar components on the estimates obtained in an accelerated manner using this technique.
2

Total Ionizing Dose and Dose Rate Effects on (Positive and Negative) BJT Based Bandgap References

January 2019 (has links)
abstract: Space exploration is a large field that requires high performing circuitry due to the harsh environment. Within a space environment one of the biggest factors leading to circuit failure is radiation. Circuits must be robust enough to continue operation after being exposed to the high doses of radiation. Bandgap reference (BGR) circuits are designed to be voltage references that stay stable across a wide range of supply voltages and temperatures. A bandgap reference is a piece of a large circuit that supplies critical elements of the large circuit with a constant voltage. When used in a space environment with large amounts of radiation a BGR needs to maintain its output voltage to enable the rest of the circuit to operate under proper conditions. Since a BGR is not a standalone circuit it is difficult and expensive to test if a BGR is maintaining its reference voltage. This thesis describes a methodology of isolating and simulating bandgap references. Both NPN and PNP bandgap references are simulated over a variety of radiation doses and dose rates. This methodology will allow the degradation due to radiation of a BGR to be modeled easily and affordably. It can be observed that many circuits experience enhanced low dose rate sensitivity (ELDRS) which can lead to failure at low total ionizing doses (TID) of radiation. A compact model library demonstrating degradation of transistors at both high and low dose rates (HDR and LDR) will be used to show bandgap references reliability. Specifically, two bandgap references being utilized in commercial off the shelf low dropout regulators (LDO) will be evaluated. The LDOs are reverse engineered in a simulation program with integrated circuit emphasis (SPICE). Within the two LDOs the bandgaps will be the points of interest. Of the LDOs one has a positive regulated voltage and one has a negative regulated voltage. This requires an NPN and a PNP based BGR respectively. This simulation methodology will draw conclusions about the above bandgap references, and how they operate under radiation at different doses and dose rates. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2019

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