Commercial power MESFET's with Ti/W/Au gate metallization show a failure mode consisting of decrease in I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dss</inf> and V xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> an increase R xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> . The mechanism was investigated by electrical structural analyses SEM, microprobe, Auger spectrometry, turns out to be thermally activated Au-GaAs interdiffusion...

In this paper, a novel capacitive array-sensor to visualize two-phase flow by measuring liquid holdup in pipe cross-section is introduced. The principle based on the difference between electrical permittivity of phases. sensor consists two copper rings being an emitter and one receiver ring. ring divided into segments, which are individually interrogated electronics fast manner. way, images directly generated from acquired signals electrodes way that it visually represents investigated flow,...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Integrated current-sensing circuits intended for smart-power and embedded applications featuring galvanic isolation are implemented. They based on magnetic detection using a CMOS-compatible split-drain transistor that provides very linear output current versus field. Two approaches used to generate the field: <emphasis emphasistype="italic">coil</emphasis> approach emphasistype="italic">...

This paper describes a course in Smart Power based on the introduction of an innovative educational tool-a preprocessed integrated circuit. The methodology used to introduce students issue design, resorting low cost standard CMOS technology is presented. theoretical support envisaged provide required knowledge specify characteristics and performance most common blocks develop skills for monolithic integration. Through simulation, experimental characterization, were able experience different...

Integrated current sensing circuits intended for Smart-Power and embedded applications featuring galvanic isolation are implemented. They based on magnetic detection using the CMOS compatible split-drain transistor (MAGFET) that provides a very linear output versus field. Two approaches used to generate The Coil approach Strip approach. In first one be sensed flows through an integrated coil placed atop produces relatively strong coupling enough cause detectable current. second features...

This paper introduces a direct-imaging sensor based on multiple capacitance (permittivity) measurements. The is fabricated in flexible printed-circuit board (PCB) technology and comprises driving ring electrode number of detecting electrodes flush-mounted into pipe peripheral. Direct images are generated representing the cross-sectional distribution phases two-phase flow. A prototype was built system tested three different ways. Firstly an air-water stratified mixture, secondly air-oil...

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> An excess-noise current in CMOS Magnetic Sensitive Field Effect Transistor (MAGFET) split-drain transistors is investigated, and a new noise model proposed. The based on the existence of transversal that stems from inversion charge layer MOS transistor channel. This current, along with one predicted by classical transistor, produces total current. Noise spectral density measurements were carried...

This work describes the development of flexible sensor to monitor moisture level in pieces wood, where is stuck. The manufactured consists a rectangular flat two-wire coil whose operation based on resonance frequency ( f o). capacitance C ) depends electric permittivity therefore, moisture. approach useful for planar or cylindrical objects. However, bending fit it around object changes magnetic links and thus its self-inductance L (and o as well). Regarding this issue, paper behavior...

A current sensor circuit intended for integrated smart-power applications featuring galvanic isolation is devised. It based on magnetic detection using the CMOS compatible split-drain transistors (MAGFET) that provides linear output versus field from DC to several MHz range. An built in 0.35 mum technology presented an conversion factor of 500 nA/A, corner frequency around 1 and thermal spectral density 60 pA/radicHz a power dissipation less than 15 mW

In this paper, measurement results of noise power spectral density in p-channel split-drain MAGFETs operating under various levels bias current are presented and discussed. It has been observed that correlation increases for decreasing current. For currents below 5 /spl mu/A, is higher than 50%, rising rapidly towards total correlation. These indicate type magnetic sensor can be used low level detection, contradicting what so far mentioned the literature. Measurements were made ranging from...

This paper proposes a multipoint platform for Power Quality analysis featuring low-cost computational algorithms and wireless reporting capability, practical steady-state real-time of dips, swells interruptions as well harmonic content in electrical systems, based on the standard IEC 61000-4-30.

Este artigo apresenta a análise e o procedimento de projeto-de um novo conversor CC-CC Ponte Completa PWM , usando célula comutação ZVS - para se conseguir suave. São também apresentados resultados experimentais obtidos partir protótipo laboratório 1500W. É demonstrado que inclusão chaves auxiliares não modifica padrão chaveamento PWM. Testes bancada com confirmam circuito proposto alto rendimento comporta-se como uma fonte tensão constante larga faixa variação da potência saída.

This paper features a step-by-step procedure for designing, simulate, and manufacture bandpass filter using an inductive window topology within the substrate integrated waveguide (SIW) technology. We have chosen operating frequency in microwave range compatible with IoT circuits, employing dielectric material, FR-4, which is low cost widely accessible. Even though it not most suitable material circuits above few gigahertz, we propose to evaluate challenges poses on design, addition...

An excess noise current in CMOS MAGFET split drain transistor is investigated and a new model proposed. It based on the existence of transversal that stems from inversion charge MOS channel. This along with one predicted by classical produces total split-drain current. impacts signal-to-noise ratio minimum detectable magnetic field, parameters interest CMOS-based sensors. Noise measurement were applied to verify combined effect this currents. Essentially, it has been observed negative...

This paper presents the analysis and design procedures of a new DC-DC full bridge pulse-width modulation (PWM) converter, using zero voltage switch (ZVS)-PWM commutation cell to achieve soft switching. Experimental results obtained from laboratory prototype rated 1500 W are also presented. It is demonstrated that inclusion auxiliary switches does not modify PWM switching pattern. Bench tests on confirm proposed circuit exhibits high efficiency behaves as constant source over an extended...

In this paper, a heater with flexible resistance coupled to steel plate is modeled. Because it flexible, type of built be attached objects that will heated regardless their shape. Starting from the energy balance, differential equation defines system's behavior obtained. The resulting system non-linear and, in order obtain transfer function, linearization carried out at an operating point, obtaining linear model. linearized equation, function calculated. Following that, power step applied...

This paper describes the development of one axis wind speed measurement equipment, applying cross correlations techniques and ultrasound sensors. It can be used in tubes, climate stations farms where is necessary. The built prototype a connected set DE0-Nano board, signal acquisition printed circuit board two pairs PCB also has circuits for sensors exciting PC communications to store sampled signals. Inside FPGA chip, system based NIOS processor was developed through QSYS tool. There are...

Planar transformers are ideal for power electronic applications where high-density energy processing capabilities and low losses required, however, ferrite core weight volume still an issue in some applications, e.g. very thin-profile boards planar assemblies. In this paper, it is proposed a methodology to build the entire transformer using lithography electroplating techniques, much alike procedures employed conventional printed circuit board (PCB) industry, with minor adjustment setups....

Polyimide films have unique characteristics and are used to build versatile resistant heaters that adequate for applications in diverse areas. Their flexibility allows them take multiple shapes but may result intricate mathematical modeling. In this paper, a heater with flexible resistance coupled steel plate is modeled compared empirical measurements. The theoretical analysis of the system's behavior begins determining differential equations from energy balance. resulting non-linear systems...

This paper presents the analysis and design procedures of a new DC-DC full bridge PWM converter using ZVS-PWM commutation cell to achieve soft switching. Experimental results obtained from laboratory prototype rated 1500 W are also presented. It is demonstrated that inclusion auxiliary switches do not modify switching pattern. Bench tests on confirm proposed circuit exhibits high efficiency behaves as constant voltage source over an extended power output range.