Operational Amplifiers
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Power amplifier circuits for functional electrical stimulation systems
Abstract Introduction: Functional electrical stimulation (FES) is a technique that has been successfully employed in rehabilitation treatment to mitigate problems after spinal cord injury (SCI). One of the most relevant modules in a typical FES system is the power or output amplifier stage, which is responsible for the application of voltage or current puls
Res. Biomed. Eng.. Publicado em: 2017-06
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2. Hybrid distributed Raman/EDFA amplifier with hybrid automatic gain control for reconfigurable WDM optical networks
Nowadays, optical amplifiers designs are induced by new requirements generated by optical networks. The introduction of WDM reconfigurable networks with increasing rate from 10-40 Gb/s to 100 Gb/s and beyond, demand new optical amplifiers development with improved gain spectral flatness and noise figure for all operational range of input powers and set-point
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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3. Impacto dos desvios de tensão de limiar induzidos por radiação ionizante no desempenho dos blocos básicos de dois amplificadores operacionais complementares
Este trabalho estuda os efeitos de dose total ionizante (TID ¿ Total Ionizing Dose) em amplificadores operacionais e em seus blocos básicos de construção. A radiação ionizante presente no espaço pode afetar o funcionamento das estruturas MOS, sendo que um dos parâmetros mais prejudicados é a tensão de limiar (Threshold Voltage). Em virtude da difer
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2012
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4. A new adaptive analog test and diagnosis system
This paper presents a low-cost analog test system with diagnosis capabilities. The tester is able to detect faults in any linear circuit by learning a reference circuit behavior in a first step, and comparing this behavior against the output of the circuit under test in a second step. For a faulty circuit, a third step takes place to locate the fault. The di
Publicado em: 2011
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5. A low voltage and high efficiency class D amplifier based on sima-delta modulator designed for hearing-aids applications / Amplificador de audio classe D baseado em modulação sigma-delta destinado a aparelhos auditivos
This thesis presents the design of a firstorder ?-? audioband power amplifier optimized for hearing aid (HA) amplification. The majority of HAs use a 1.1V battery and require very low current consumption to improve battery life. This work made use of amplifiers and comparators based on CMOS inverters because such an inverter, with a 1.1V battery, can operate
Publicado em: 2007
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6. Desenvolvimento de sistemas portáteis de monitoramento eletroquímico. / Development of portables electrochemical monitoring systems.
This work presents the development of two different portable electrochemical detection systems. Both systems are applicable in environment and biomedical areas. The electrochemical detection techniques have many interesting advantages, when compared to other detections techniques, such as good sensitivity, good selectivity, and low maintenance cost. The dete
Publicado em: 2007
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7. Multimodal vibration damping through piezoelectric patches and optimal resonant shunt circuits
Piezoelectric elements connected to shunt circuits and bonded to a mechanical structure form a dissipation device that can be designed to add damping to the mechanical system. Due to the piezoelectric effect, part of the vibration energy is transformed into electrical energy that can be conveniently dissipated. Therefore, by using appropriate electrical circ
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2006-09
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8. Design of low-voltage CMOS class-AB operational amplifiers / Projeto de amplificadores operacionais CMOS classe-AB operando em baixa tensão de alimentação
This dissertation describes the process of designing rail-to-rail operational amplifiers in CMOS technology. To accomplish this, the author focused on four distinct structures. The four topologies have rail-to-rail input stage with gm-control circuit and Class-AB output stage with quiescent-current control. The specification of three configurations included
Publicado em: 2006
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9. Design technique for a folded cascode, class AB, operational amplifier, in CMOS tecnology. / Técnica para o projeto de um amplificador operacional folded cascode, classe AB, em tecnologia CMOS.
A tendência mundial em torno de sistemas SoC System on Chip baseados em processo CMOS Complementary Metal Oxide Semiconductor digital, apresenta cada vez mais desafios aos projetistas de circuitos integrados. Em especial se observa que enquanto os projetistas de circuitos digitais podem contar com bibliotecas cada vez mais completas de células
Publicado em: 2006
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10. Compensação em frequencia de amplificadores CMOS de dois e tres estagios
This dissertation analyzes the project techniques used in frequency compensation of CMOS operational amplifiers (op-amps). A collection of 10 op-amps, including two and three stages amplifiers was fabricated for test. Power consumption, unity gain frequency and stability were aimed for performance comparison. Poles movement analysis was extensively exploited
Publicado em: 2004
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11. Simulação analogica de linhas de transmissão utilizando-se circuitos integrados
The main goal of this work was the development of a didatic tool, based on integrated circuits, for the analog simulation of transmission lines. The obtained results allow for a quantitative analysis of the currents and voltages along the line. Initially, a study of transmission line models were carried out. As the circuit was implemented with operational am
Publicado em: 1994