Search results for "Transistor"
showing 10 items of 234 documents
SIC based solid state protections switches for space applications
2017
Development and technology maturation of Silicon Carbide (SiC) power transistors over the last 15 years has motivated its study in aerospace systems. When compared with Si devices, superior voltage blocking capacity and the capability of operation at higher temperatures, give important advantages in space power electronics applications, similar to what happens in terrestrial electronics. This paper discusses the use of SiC power transistors for Solid State Power Switches especially addressed to the space segment. Two applications will be covered, the first is the Solid State Shunt Switch, widely used in high power Direct Energy Transfer (DET) photovoltaic power regulators and the second is …
Partial discharge of gel insulated high voltage power modules subjected to unconventional voltage waveforms
2016
Performances and duration of the new generation of high voltage power electronic components are dependent on dielectric materials aim to insulating their internal terminals. The presence of defects, some due to faults generated during the manufacturing process, but also due to the internal design of layers and connections, can cause local enhancements of electric field and consequently possible activity of partial discharges phenomena or other effects (aging, tracking) that may result in reduction of device reliability. Furthermore, the usage of unconventional voltage waveforms, like square waves or pulse width modulated waves, additionally increases the electrical aging of the insulation s…
Multi-pulse characterization of trapping/detrapping mechanisms in AlGaN/GaN high electromobility transistors
2019
GaN high-electro mobility transistors (HEMTs) are among the most promising candidates for use in high-power, high-frequency, and high-temperature electronics owing to their high electrical breakdown threshold and their high saturation electron velocity. The applications of these AlGaN/GaN HEMTs in power converters are limited by the surface trapping effects of drain-current collapse. Charge-trapping mechanisms affect the dynamic performance of all GaN HEMTs used in power switching applications. This study analyzes the dynamic resistance of GaN HEMTs and finds that the effects of dynamic resistance can be suppressed by controlling switching conditions and on-off cycles.
Comparison of Single Event Transients Generated at Four Pulsed-Laser Test Facilities-NRL, IMS, EADS, JPL
2012
Four pulsed-laser single-event effects systems, differing in wavelength and pulse width, were used to generate single event transients in a large-area silicon photodiode and an operational amplifier (LM124) to determine how transient amplitude and charge collection varied among the different systems. The optical wavelength and the focused spot size are the primary factors influencing the resultant charge density profile. In the large-area photodiode the transients can be distorted by high charge-injection densities that occur for tightly focused, higher energy optical pulses. When the incident laser-pulse energies are corrected for reflection losses and photon efficiency, with collection de…
Silicon dosimeters based on Floating Gate Sensor: design, implementation and characterization
2020
A rad-hard monolithic dosimeter has been implemented and characterized in a standard 180 nm CMOS technology. The radiation sensor (C-sensor) is based on a Floating Gate (FG) MOS discharge principle. The output current is processed by a current-to-voltage (I/V) interface and then converted by a 5-bit flash ADC. The dosimeter is re-usable (FG can be recharged) and can detect a dose up to 1krad (Si) with a resolution of 30rad (Si) typical over temperature 0 to 85°C range. The ADC allows easy further signal processing for calibration and averaging, etc. The power consumption of C-sensor plus I/V interface is < 2mW from a 5 V power supply. The overall layout area is less than 0.25mm2. The Rad…
Mapping brain activity with flexible graphene micro-transistors
2016
arXiv:1611.05693v1.-- et al.
Estudio de la fiabilidad de los dispositivos HEMT de GaN
2021
El presente trabajo de tesis en Ingeniería Electrónica tiene como objetivo el estudio de la fiabilidad de dispositivos HEMT (High Electron Mobility Transistor) de GaN (Gallium Nitride). Gracias a las ventajas teóricas en el uso de dispositivos GaN frente a dispositivos de Silicio y a la aparición de dispositivos GaN que mejoran las prestaciones de sus homónimos de Silicio, el siguiente paso, es el estudio de la fiabilidad que presentan estos dispositivos en la actualidad, con el objetivo de mejorarlos e investigar los límites actuales en determinadas aplicaciones de potencia. La investigación realizada en esta tesis se divide en tres partes claramente diferenciadas. La primera de ellas trat…
Cutaneous Recording and Stimulation of Muscles Using Organic Electronic Textiles
2016
International audience; Electronic textiles are an emerging field providing novel and non-intrusive solutions for healthcare. Conducting polymer-coated textiles enable a new generation of fully organic surface electrodes for electrophysiological evaluations. Textile electrodes are able to assess high quality muscular monitoring and to perform transcutaneous electrical stimulation.
Computationally efficient dynamical analysis of optically driven injection-locked GaAs FET oscillators
1995
A computer-aided simulation technique for the dynamical analysis of a class of GaAs FET optically-driven injection-locked oscillators (ODILO's) is presented. By combining a measurement-derived nonlinear model of the illuminated transistor with a phasor-domain analysis method, a first-approximation - but phenomenologically complete - differential model of the synchronized oscillator is derived. Since amplitude and phase of waveform evolutions are directly addressed and evaluated in a stroboscopic-time scale, the calculation of the transient response to modulated input signals can be done in a more user-friendly and computationally efficient manner than possible through conventional time-doma…
Influence of Active Device Nonlinearities on the Determination of Adler's Injection.Locking Q-Factor
2011
The problem of the correct evaluation of Q-factor appearing in Adler's equation for injection-locking is addressed. Investigation has shown that recent results presented in the literature, while extending applicability of the original method, do not completely account for nonlinear effects occurring when two-port active devices are involved. To overcome such limitation, use can be made of a newly developed theory in the dynamical complex envelope domain, capable of providing first-approximation exact dynamical models of driven quasi-sinusoidal oscillators. Some preliminary results are presented here concerning a class of injection-locked oscillators with single-loop feedback type configurat…