The influence of a mounting manner of power MOS transistors on characteristics of the Totem-Pole circuit with RLC load

2016 ◽  
Vol 33 (3) ◽  
pp. 176-180 ◽  
Author(s):  
Pawel Górecki ◽  
Krzysztof Górecki
Keyword(s):  
The Other ◽  
Oxide Semiconductor ◽  
Mos Transistors ◽  
Content Type ◽  
Mos Transistor ◽  
Self Heating ◽  
Cross Section Area ◽  
Section Area ◽  
Wide Range ◽  
State Resistance

Purpose The paper aims to consider the problem of the influence of mounting power metal-oxide semiconductor (MOS) transistors operating in the Totem–Pole circuit on energy losses in this circuit. Design/methodology/approach Using the computer simulation in SPICE software, the influence of such factors as on-state resistance of the channel of the MOS transistor, the self-heating phenomena in this transistor and resistance of wires connecting transistors with the other part of the circuit on characteristics of the considered circuit operating with resistor, inductor and capacitor (RLC) load is analyzed. The selected results of calculations are compared with the results of measurements. Findings On the basis of the obtained results of calculations, some recommendations concerning the manner of mounting the considered transistors, assuring a high value of watt-hour efficiency of the process of energy transfer to the load are formulated. Research limitations/implications The investigations were performed in the wide range of the frequency of the signal stimulating the considered circuit, but the results of calculations were presented for 2 selected values of this frequency only. Practical implications The considered analysis was performed for the circuit dedicated to power supplied of an elecrolyser. Originality/value Presented results of calculations prove that in some situations, the value of watt-hour efficiency of the considered circuit is determined by the length and the cross-section area of the applied wires bringing the signal to the connectors of the transistors and to load. On the other hand, self-heating phenomena in the power MOS transistors can lead to doubling power losses in these devices.

scholarly journals Study and Assessment of Defect and Trap Effects on the Current Capabilities of a 4H-SiC-Based Power MOSFET

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 735
Author(s):  
Fortunato Pezzimenti ◽  
Hichem Bencherif ◽  
Giuseppe De Martino ◽  
Lakhdar Dehimi ◽  
Riccardo Carotenuto ◽  
...  
Keyword(s):  
Drain Current ◽  
Oxide Semiconductor ◽  
Temperature Dependent ◽  
Channel Mobility ◽  
Blocking Voltage ◽  
Current Voltage ◽  
Wide Range ◽  
Temperature Ranges ◽  
Joint Contribution ◽  
State Resistance

A numerical simulation study accounting for trap and defect effects on the current-voltage characteristics of a 4H-SiC-based power metal-oxide-semiconductor field effect transistor (MOSFET) is performed in a wide range of temperatures and bias conditions. In particular, the most penalizing native defects in the starting substrate (i.e., EH6/7 and Z1/2) as well as the fixed oxide trap concentration and the density of states (DoS) at the 4H-SiC/SiO2 interface are carefully taken into account. The temperature-dependent physics of the interface traps are considered in detail. Scattering phenomena related to the joint contribution of defects and traps shift the MOSFET threshold voltage, reduce the channel mobility, and penalize the device current capabilities. However, while the MOSFET on-state resistance (RON) tends to increase with scattering centers, the sensitivity of the drain current to the temperature decreases especially when the device is operating at a high gate voltage (VGS). Assuming the temperature ranges from 300 K to 573 K, RON is about 2.5 MΩ·µm2 for VGS > 16 V with a percentage variation ΔRON lower than 20%. The device is rated to perform a blocking voltage of 650 V.

Effect of Technology Scaling on MOS Transistor Performance with High-K Gate Dielectrics

2002 ◽  
Vol 716 ◽  
Author(s):  
Nihar R. Mohapatra ◽  
Madhav P. Desai ◽  
Siva G. Narendra ◽  
V. Ramgopal Rao
Keyword(s):  
Gate Dielectric ◽  
Gate Dielectrics ◽  
Channel Length ◽  
Mos Transistors ◽  
Short Channel ◽  
Technology Scaling ◽  
Mos Transistor ◽  
Wide Range ◽  
Impact Of Technology ◽  
The Impact

AbstractThe impact of technology scaling on the MOS transistor performance is studied over a wide range of dielectric permittivities using two-dimensional (2-D) device simulations. It is found that the device short channel performance is degraded with increase in the dielectric permittivity due to an increase in dielectric physical thickness to channel length ratio. For Kgate greater than Ksi, we observe a substantial coupling between source and drain regions through the gate dielectric. We provide extensive 2-D device simulation results to prove this point. Since much of the coupling between source and drain occurs through the gate dielectric, it is observed that the overlap length is an important parameter for optimizing DC performance in the short channel MOS transistors. The effect of stacked gate dielectric and spacer dielectric on the MOS transistor performance is also studied to substantiate the above observations.

Hardening of Al-Mg-Si Alloys and Effect of Particle Structure

2012 ◽  
Vol 706-709 ◽  
pp. 283-288 ◽  
Author(s):  
Sverre Gulbrandsen-Dahl ◽  
Calin D. Marioara ◽  
Ketill Olav Pedersen ◽  
Knut Marthinsen
Keyword(s):  
Mechanical Strength ◽  
Volume Fraction ◽  
Number Density ◽  
Particle Structure ◽  
Microstructure Characteristics ◽  
Cross Section Area ◽  
Section Area ◽  
Wide Range ◽  
Hardening Models ◽  
Particle Statistics

In the present study, several Al-Mg-Si alloys have been studied with respect to microstructure characteristics, i.e. particle statistics, and resulting mechanical properties. The alloys and tempers represents a wide range of type of hardening particles stretching from pre-β’’, via β’’, to post-β’’ particles such as β’, U1, U2 and B’, and various sizes, number densities and volume fractions of these particles. The correlation between volume fraction of hardening precipitates and mechanical strength is strong within alloys with pre-β’’ and β’’ as the main hardening precipitates, but this correlation does not fit for alloys with post-β’’ precipitates. However, a strong correlation between mechanical strength and both number density and cross-section area of the hardening precipitates is found, independent of type of precipitate. The consequences of these correlations are discussed with respect to proposed hardening models found in the literature.

scholarly journals Structural Insights into the Subclass B3 Metallo-β-Lactamase SMB-1 and the Mode of Inhibition by the Common Metallo-β-Lactamase Inhibitor Mercaptoacetate

2012 ◽  
Vol 57 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Jun-ichi Wachino ◽  
Yoshihiro Yamaguchi ◽  
Shigetarou Mori ◽  
Hiromasa Kurosaki ◽  
Yoshichika Arakawa ◽  
...  
Keyword(s):  
Amino Acid ◽  
Active Site ◽  
Hydrolytic Activity ◽  
The Other ◽  
Amino Acid Residues ◽  
Hydrogen Bond Interaction ◽  
Content Type ◽  
Carboxylate Oxygen ◽  
Wide Range ◽  
Environmental Bacteria

ABSTRACTA novel subclass B3 metallo-β-lactamase (MBL), SMB-1, recently identified from aSerratia marcescensclinical isolate, showed a higher hydrolytic activity against a wide range of β-lactams than did the other subclass B3 MBLs, i.e., BJP-1 and FEZ-1, from environmental bacteria. To identify the mechanism underlying the differences in substrate specificity among the subclass B3 MBLs, we determined the structure of SMB-1, using 1.6-Å diffraction data. Consequently, we found that SMB-1 reserves a space in the active site to accommodate β-lactam, even with a bulky R1 side chain, due to a loss of amino acid residues corresponding to F31 and L226 of BJP-1, which protrude into the active site to prevent β-lactam from binding. The protein also possesses a unique amino acid residue, Q157, which probably plays a role in recognition of β-lactams via the hydrogen bond interaction, which is missing in BJP-1 and FEZ-1, whoseKmvalues for β-lactams are particularly high. In addition, we determined the mercaptoacetate (MCR)-complexed SMB-1 structure and revealed the mode of its inhibition by MCR: the thiolate group bridges to two zinc ions (Zn1 and Zn2). One of the carboxylate oxygen atoms of MCR makes contact with Zn2 and Ser221, and the other makes contact with T223 and a water molecule. Our results demonstrate the possibility that MCR could be a potent inhibitor for subclass B3 MBLs and that the screening technique using MCR as an inhibitor would be effective for detecting subclass B3 MBL producers.

scholarly journals The separation wall effect of a volute twin entry cross section area on the mixed inflow turbine performance

2020 ◽  
Vol 41 (1) ◽  
pp. 11-20
Author(s):  
Bencherif Mohammed Menaouar ◽  
Hamel Mohamed ◽  
Bencherif Mohamed ◽  
Guelailia Ahmed ◽  
Hamidou Mohamed Kamel
Keyword(s):  
Cross Section ◽  
Solid Wall ◽  
Reverse Flow ◽  
Flow Behavior ◽  
The Other ◽  
Turbine Performance ◽  
Radial Plane ◽  
Cross Section Area ◽  
Section Area ◽  
Turbocharging System

The pulse turbocharging system is used in many diesel engines and it is fortunate that nozzleless mixed turbines allow unsteady flow with less performance losses. It operates with a double or sometimes triple-entry casing creating different flow regimes in each sector. A nozzleless casing is used. The division of the cross section area takes the form of a solid wall in the radial plane. When the flow rate through one or the other volute inlet drops to zero, some reverse flow is observed from the other inlet. This situation suffers undesirable effects, diminishing the benefits of the divided volute casing types. A numerical investigation on the effect of the length of the dividing wall in the radial plane is performed using the ANSYS code. This possibility is explored and the results show that extending the wall to a limiting length enhances the flow behavior with better performance.

Compact electrothermal model of laboratory made GaN Schottky diodes

2020 ◽  
Vol 37 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Krzysztof Górecki ◽  
Paweł Górecki
Keyword(s):  
Integrated Circuit ◽  
Design Methodology ◽  
Schottky Diodes ◽  
Parameters Estimation ◽  
Model Parameters ◽  
Content Type ◽  
Self Heating ◽  
Dc Characteristics ◽  
Wide Range ◽  
Electrothermal Simulation

Purpose The purpose of this paper is to propose a simple electrothermal model of GaN Schottky diodes, and its usefulness for circuit-level electrothermal simulation of laboratory-made devices is proved. Design/methodology/approach The compact electrothermal model of this device has the form of a subcircuit for simulation program with integrated circuit emphasis. This model takes into account influence of a change in ambient temperature in a wide range as well as influence of self-heating phenomena on dc characteristics of laboratory-made GaN Schottky diodes. The method of model parameters estimation is described. Findings It is shown that temperature influences fewer characteristics of GaN Schottky diodes than classical silicon diodes. The discussed model accurately describes properties of laboratory made GaN Schottky diodes. Additionally, the measured and computed characteristics of these diodes are shown and discussed. Research limitations/implications The presented model together with the results of measurements and computations is dedicated only to laboratory-made GaN Schottky diodes. Originality/value The presented investigations show that characteristics of laboratory-made GaN Schottky diodes visibly change with temperature. These changes can be correctly estimated using the compact electrothermal model proposed in this paper. The correctness of this model is proved for four structures of such diodes characterised by different values of structure area and a different assembly process.

Characterization of MOS Transistors Using Dynamic Backside Reflectance Modulation Technique

2011 ◽  
Author(s):  
J.K.J. Teo ◽  
C.M. Chua ◽  
L.S. Koh ◽  
J.C.H. Phang
Keyword(s):  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Mos Transistors ◽  
Modes Of Operation ◽  
Mos Transistor ◽  
Modulation Technique ◽  
Laser Reflectance ◽  
Channel Lengths ◽  
Model Support

Abstract The channel of metal-oxide-semiconductor (MOS) transistors at different modes of operation has been characterized using dynamic backside laser reflectance modulation technique for different NMOS and PMOS transistors with different channel lengths. The reflectance modulations contain a primary peak near the drain-end when the MOS transistor is in saturation mode. Comparison studies with a Pseudo-Two-Dimensional analytical model support the hypothesis that the observed peak corresponds to the pinch-off point.

A framework for effective crisis response

2016 ◽  
Vol 29 (4) ◽  
pp. 464-483 ◽  
Author(s):  
Nitin Pangarkar
Keyword(s):  
Poor Response ◽  
Crisis Response ◽  
The Other ◽  
Effective Response ◽  
Case Study Methodology ◽  
Content Type ◽  
Critical Dimensions ◽  
Other Hand ◽  
Wide Range ◽  
The Right

Purpose – The purpose of this paper is to propose a framework for effective crisis response. Design/methodology/approach – The methodology involves a qualitative examination of responses by companies that have been judged by analysts to be varyingly effective. Toyota, for instance, had a poor response to its product quality and recall crisis. Singapore Airlines on the other hand, is often cited as an exemplar for an effective response to the crash of its flight SQ 006 in Taiwan. Findings – This research finds that organizations with a strong commitment to doing the right thing for stakeholders and a high readiness are most likely to effectively respond to crises. Organizations lacking in one of the two critical dimensions (commitment to stakeholders and/or readiness), on the other hand, are likely to have ineffective responses with possible post-crisis losses in competitive (e.g. market share) and financial (e.g. penalties) terms. Research limitations/implications – The case study methodology implies limitations about generalizability. The framework may also be less useful in crises where there is ambiguity about the genesis of the crisis and its implications, such as the disappearance of the Malaysian Airlines’ MH 370 flight. Practical implications – Since crises are commonplace and can impact any company, the framework can be useful for a wide range of companies. Originality/value – The proposed framework fills a gap in the understanding about why some companies have effective responses to crises and others do not. Prior literature has often adopted narrower perspectives such as the skills and the personality of the CEO, pre-crisis drills and effective communication strategies post-crisis. This study argues that while these factors are important, they are not sufficiently strategic.

scholarly journals Inversion charge density of MOS transistor with generalized logistic functions

2018 ◽  
Vol 50 (2) ◽  
pp. 225-235
Author(s):  
Tijana Kevkic ◽  
Vladica Stojanovic ◽  
Vera Petrovic ◽  
Dragan Randjelovic
Keyword(s):  
Charge Density ◽  
Inversion Layer ◽  
Oxide Thickness ◽  
Oxide Semiconductor ◽  
Smooth Transition ◽  
Smoothing Factor ◽  
Mos Transistor ◽  
Wide Range ◽  
Inversion Charge ◽  
Quantum Mechanical Effects

In this paper, the expression for the charge density in inversion layer at the surface of semiconductor has been improved. The improvement is related to the replacement of an empirical smoothing factor by new one which has generalized logistic (GL) functional form. The introduction of the GL function of the second type in the original interpolating expression leads to continual and smooth transition of the inversion charge density (ICD) between different regions of metal-oxide-semiconductor (MOS) operation. Moreover, in this way any empirical determinations are avoided. The simulated values of the ICD match closely with the numerical results of implicit charge sheet model for a wide range of dopant concentration and oxide thickness. In addition, the proposed GL fitting procedure has been also extended in the case where quantum mechanical effects play important role in inversion mode of scaled MOS devices.

Influences of fuel concentration, fuel volume, initial temperature, and initial pressure on flame propagation and flameproof distance of methane-air deflagrations

2016 ◽  
Vol 26 (6) ◽  
pp. 1710-1728 ◽  
Author(s):  
Bingyou Jiang ◽  
Zegong Liu ◽  
Shulei Shi ◽  
Feng Cai ◽  
Jian Liu ◽  
...  
Keyword(s):  
Flame Propagation ◽  
Arrival Time ◽  
Initial Temperature ◽  
Initial Pressure ◽  
Test Point ◽  
Content Type ◽  
Fuel Concentration ◽  
Cross Section Area ◽  
Section Area ◽  
Changing Trend

Purpose – The purpose of this paper is to understand a flameproof distance necessary to avoid the flame harms to underground personnel which may have great significance to the safety of underground personnel and the disaster relief of gas explosions in coal mines. Design/methodology/approach – Through a roadway with a length of 100 m and a cross-section area of 80 mm×80 mm, the flame propagation of premixed methane-air deflagrations were simulated by using AutoReaGas software for various fuel concentrations (7, 8, 9.5, 11, and 14 percent), fuel volumes (0.0128, 0.0384, 0.064, and 0.0896 m3), initial temperatures (248, 268, 288, 308, and 328 K), and initial pressures (20, 60, 101.3, 150, and 200 kPa). Findings – The maximum combustion rate for each point follows a changing trend of increasing and decreasing with the distance increasing from the ignition source, and it increases with the fuel volume increasing or the initial pressure increasing, and decreases with the initial temperature increasing. However, increasing the initial temperature increases the flame arrival time for each point. The flameproof distance follows a changing trend of increasing and decreasing with the fuel concentration increasing, and it linearly increases with the fuel volume increasing or the initial temperature increasing. However, the flameproof distances are all 17 m for various initial pressures. Originality/value – Increasing initial temperature increases flame arrival time for each test point. Flameproof distance increases and then decreases with fuel concentration increasing. Increasing fuel volume or initial temperature linearly increases flameproof distance. Initial pressure has little impact on the flameproof distance.

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