Journal articles on the topic 'High voltages in art'
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1
Singh, R., S. Creamer, E. Lieser, S. Jeliazkov, and S. Sundaresan. "HIGH TEMPERATURE ULTRA HIGH VOLTAGE SIC THYRISTORS." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2010, HITEC (January 1, 2010): 000167–73. http://dx.doi.org/10.4071/hitec-rsingh-tp25.
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Through a systematic study, Silicon Carbide Gate Turn Off (GTO) Thyristors with record performance are demonstrated. Several Anode-Gate interdigitation schemes (raster, hex and involute) were explored to investigate their effect on the static as well as switching characteristics. An optimized edge-termination was employed that resulted in the achievement of near-theoretical forward blocking voltages (>8.1kV), and high yields (>60% on 8mm×8mm) on GTO Thyristors with 60μm/5×1014 cm−3 voltage-blocking epitaxial layers. A low differential specific on-resistance of 2.55 mΩ-cm2, and low on-state voltage drop were measured at 500 A/cm2. High Temperature forward I-V and reverse I-V characteristics show extremely stable performance with temperature, in contrast to state-of-the-art Si GTO Thyristors. Turn-on transient characteristics show a stable delay time of about 400 nano-seconds, and a rise-time that decreases with increasing temperature. Detailed high temperature turn-off measurements conducted using Anode-Switched mode was used to extract the value of minority carrier lifetimes as a function of temperature for the first time.
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Irace, Andrea, Vincenzo d'Alessandro, Giovanni Breglio, Paolo Spirito, Andrea Bricconi, Rossano Carta, Diego Raffo, and Luigi Merlin. "Electrothermal Issues in 4H-SiC 600 V Schottky Diodes in Forward Mode: Experimental Characterization, Numerical Simulations and Analytical Modelling." Materials Science Forum 527-529 (October 2006): 1151–54. http://dx.doi.org/10.4028/www.scientific.net/msf.527-529.1151.
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The electrothermal behavior of 4H-SiC 600 V Schottky diodes operated in forward mode is analyzed through numerical and analytically-based simulations. It is shown that the unexpected occurrence of voltage surges systematically detected in state-of-the-art devices is a thermally-induced effect due to the compound contribution of a) the negative temperature coefficient of the forward current at high voltages and b) the relatively high package-to-ambient thermal resistance. As a main result, it is demonstrated that the proposed approaches are suitable to accurately predict the value of a “critical” current density beyond which voltage surges may arise.
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Centurelli, Francesco, Riccardo Della Sala, Pietro Monsurrò, Giuseppe Scotti, and Alessandro Trifiletti. "A Tree-Based Architecture for High-Performance Ultra-Low-Voltage Amplifiers." Journal of Low Power Electronics and Applications 12, no. 1 (February 17, 2022): 12. http://dx.doi.org/10.3390/jlpea12010012.
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In this paper, we introduce a novel tree-based architecture which allows the implementation of Ultra-Low-Voltage (ULV) amplifiers. The architecture exploits a body-driven input stage to guarantee a rail-to-rail input common mode range and body-diode loading to avoid Miller compensation, thanks to the absence of high-impedance internal nodes. The tree-based structure improves the CMRR of the proposed amplifier with respect to the conventional OTA architectures and allows achievement of a reasonable CMRR even at supply voltages as low as 0.3 V and without tail current generators which cannot be used in ULV circuits. The bias currents and the static output voltages of all the stages implementing the architecture are accurately set through the gate terminals of biasing transistors in order to guarantee good robustness against PVT variations. The proposed architecture and the implementing stages are investigated from an analytical point of view and design equations for the main performance metrics are presented to provide insight into circuit behavior. A 0.3 V supply voltage, subthreshold, ultra-low-power (ULP) OTA, based on the proposed tree-based architecture, was designed in a commercial 130 nm CMOS process. Simulation results show a dc gain higher than 52 dB with a gain-bandwidth product of about 35 kHz and reasonable values of CMRR and PSRR, even at such low supply voltages and considering mismatches. The power consumption is as low as 21.89 nW and state-of-the-art small-signal and large-signal FoMs are achieved. Extensive parametric and Monte Carlo simulations show the robustness of the proposed circuit to PVT variations and mismatch. These results confirm that the proposed OTA is a good candidate to implement ULV, ULP, high performance analog building blocks for directly harvested IoT nodes.
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Malinowski, M. "Cascaded multilevel converters in recent research and applications." Bulletin of the Polish Academy of Sciences Technical Sciences 65, no. 5 (October 1, 2017): 567–78. http://dx.doi.org/10.1515/bpasts-2017-0062.
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Abstract Multilevel converters have been intensively investigated and developed since 1960s and have found successful industrial applications. The aim of this paper is to present state of the art as well as recent research and applications of cascaded multilevel converters, which are a very interesting solution for power distribution systems and renewable energy sources. Cascaded multilevel converters can easily operate at medium and high voltage based on the series connection of power modules (cells), which use standard low-voltage component configurations. Series connections of modules (cells) allow for high quality output voltages and input currents, reduction of passive components and availability of component redundancy. Due to these features the cascaded multilevel converters have been recognized as attractive solutions for high-voltage direct-current (HVDC) transmission, solid state transformers (SST) and photovoltaic (PV) systems.
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Kirchartz, Thomas. "High open-circuit voltages in lead-halide perovskite solar cells: experiment, theory and open questions." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 377, no. 2152 (July 8, 2019): 20180286. http://dx.doi.org/10.1098/rsta.2018.0286.
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One of the most significant features of lead-halide perovskites is their ability to have comparably slow recombination despite the fact that these materials are mostly processed from solution at room temperature. The slow recombination allows achieving high open-circuit voltages when the lead-halide perovskite layers are used in solar cells. This perspective discusses the state of the art of our understanding and of experimental data with regard to recombination and open-circuit voltages in lead-halide perovskites. A special focus is put onto open questions that the community has to tackle to design future photovoltaic and optoelectronic devices based on lead-halide perovskites and other semiconductors with similar properties. This article is part of a discussion meeting issue ‘Energy materials for a low carbon future’.
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Tarter, T. S., A. Carrasco, N. Do, G. Felten, W. Nunn, and J. Church. "Hashing Processors: A New Challenge for Power Package Design." International Symposium on Microelectronics 2014, no. 1 (October 1, 2014): 000229–35. http://dx.doi.org/10.4071/isom-tp25.
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A new class of processors has emerged for high speed hashing of crypto-currency numerical constructs. The paper examines package design for processors with multiple cores running at full speed continuously and requiring high current supply at low voltages. The work described in this paper is focused on package design for high-current, high-power devices with emphasis on PDN structures and package development using state-of-the-art design, modeling and simulation toolsets.
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Delatte, Pierre, Aimad Saib, Etienne Vanzieleghem, and Jean-Christophe Doucet. "STROMBOLI®: a new platform for Isolated DC-DC Converters with reliable operation from −55°C up to 225°C." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2011, HITEN (January 1, 2011): 000167–71. http://dx.doi.org/10.4071/hiten-paper6-pdelatte.
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This paper presents a new high-temperature isolated DC-DC converter platform called STROMBOLI®. It also discusses how this converter can be associated with the various solutions proposed by CISSOID for Point-of-Load (POL) regulators that can be either linear or switched mode. STROMBOLI® has been optimized to efficiently convert input voltages up to 350V into multiple output voltages up to +/−25V. As an example, in a +/−12V symmetrical output configuration, standard STROMBOLI® can deliver 25W with efficiencies up to 70% at 225°C. The galvanic isolation between input and outputs is at least 10MΩ at 500V. As the main objective of this development was to provide designers with a solution highly flexible, scalable, and easily adaptable to their specific requirements, we selected well-known and robust flyback architecture. Efficiency has been optimized thanks to synchronous rectification. However it can be replaced by a standard rectification in order to reduce the bill-of-material (BOM). A magnetic feedback provides the output voltage temperature stability and the load regulation. STROMBOLI® also includes an Under-Voltage-Lockout (UVLO) function and the pulse-by-pulse current sensing provides intrinsic output current limitation in case of overload or short-circuits. STROMBOLI® is a state-of-the-art, turnkey reference design suitable for 225°C reliable operation and is part of high temperature DC-DC converters VOLCANO family.
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Fuse, Norikazu, Shosuke Morita, Satoru Miyazaki, Toshihiro Takahashi, and Naohiro Hozumi. "Estimation Accuracy of the Electric Field in Cable Insulation Based on Space Charge Measurement." Energies 15, no. 13 (July 5, 2022): 4920. http://dx.doi.org/10.3390/en15134920.
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Space charge measurement accuracy is crucial when assessing the suitability of cables for high-voltage direct current (DC) systems. This study assembled state-of-the-art analysis technologies, including time-domain deconvolution, to mark electric field estimation accuracy, which the present techniques achieve. The pulse electroacoustic method was applied to a 66 kV-class extruded cable, and waveforms were obtained and analyzed to reproduce the electric field distribution. The DC voltage was set to be sufficiently low so that the analysis results can be compared with Laplace’s equation. The statistical analysis of 81 waveforms under a DC voltage of 30 kV showed that the estimation accuracy was −0.3% ± 19.9% with a 95.4% confidence interval, even with the deconvolution parameter optimized. The estimated accuracy using the “reference” waveform is applied to waveforms at higher voltages since similar estimation accuracies were confirmed for waveforms obtained under a DC voltage of 45 kV.
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Yuan, Jing, Yongheng Yang, and Frede Blaabjerg. "A Switched Quasi-Z-Source Inverter with Continuous Input Currents." Energies 13, no. 6 (March 17, 2020): 1390. http://dx.doi.org/10.3390/en13061390.
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Impedance source converters as single-stage power conversion alternatives can boost and regulate the output voltages of renewable energy sources. Nevertheless, they, also known as Z-source inverters (ZSIs), still suffer from limited voltage gains and higher stresses across the components. To tackle such issues, extra diodes, passive components, and active switches can be utilized in the basic ZSIs. In this paper, a modified switched-quasi-Z-source inverter (S-qZSI) is proposed, which features continuous input currents and high boosting capability to boost output voltage by minor modifications of a prior-art topology. Furthermore, the voltage stress of the active switches is reduced, which contributes to a lower cost. The operation principles are discussed comprehensively. The performance of the proposed ZSI in terms of conversion ratio, voltage gain, and stresses on the power switches and capacitors is benchmarked with selected ZSIs. Finally, simulations and experimental tests substantiate the theoretical analysis and superior performance.
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Li, Weiyao. "Analysis of the Principle and Applications for High Voltage Device Based on SiC." Highlights in Science, Engineering and Technology 76 (December 31, 2023): 421–27. http://dx.doi.org/10.54097/t6wnh795.
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The field of high-voltage electronics is rapidly evolving, with a particular focus on materials and devices that can withstand high voltages and temperatures while maintaining reliable performance. Silicon Carbide (SiC) is one such material that has been gaining significant attention due to its unique physical and chemical properties. This study will delve into the principle and applications of high-voltage devices based on SiC, exploring its potential for use in a range of power electronic systems. This paper will first explore the principle of SiC high-voltage devices, including a detailed analysis of the physical and chemical processes involved in their operation. Subsequently, this study will discuss the current state-of-the-art in SiC device fabrication and characterize the resulting devices based on their performance metrics. This will be followed by a discussion on the potential applications of SiC high-voltage devices in power electronics and beyond. Finally, this study will address the current limitations in SiC device research and development and explore possible future research directions that may lead to improved performance and reliability of SiC devices. By delving into the principle and applications of high-voltage devices based on SiC, this paper aims to provide a comprehensive understanding of the material’s unique properties and its potential for use in a range of power electronic systems. The analysis of current limitations and prospects will aid in identifying areas for future research and development efforts, leading to the advancement of SiC high-voltage devices for even more demanding applications.
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Voronina, Natalia, and Seung-Taek Myung. "Recent Advances in Electrode Materials with Anion Redox Chemistry for Sodium-Ion Batteries." Energy Material Advances 2021 (July 30, 2021): 1–22. http://dx.doi.org/10.34133/2021/9819521.
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The development of sodium-ion batteries (SIBs), which are promising alternatives to lithium-ion batteries (LIBs), offers new opportunities to address the depletion of Li and Co resources; however, their implementation is hindered by their relatively low capacities and moderate operation voltages and resulting low energy densities. To overcome these limitations, considerable attention has been focused on anionic redox reactions, which proceed at high voltages with extra capacity. This manuscript covers the origin and recent development of anionic redox electrode materials for SIBs, including state-of-the-art P2- and O3-type layered oxides. We sequentially analyze the anion activity–structure–performance relationship in electrode materials. Finally, we discuss remaining challenges and suggest new strategies for future research in anion-redox cathode materials for SIBs.
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Garima Kapur. "CMOS Based Voltage Reference Designs for Sub - 1V." Journal of Electrical Systems 20, no. 3 (May 8, 2024): 1309–16. http://dx.doi.org/10.52783/jes.3538.
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This review paper presents an analysis of the most recent advancements in sub-1V voltage references, addressing the growing demand for ultra-low power consumption and high precision in modern integrated circuits (ICs). Voltage references are critical components in numerous applications, including IoT devices, wearable electronics, and energy-harvesting systems, where power efficiency and accuracy are paramount. It briefly discusses the challenges associated with designing voltage references at such low voltages, such as limited headroom, reduced noise margin, and process variations. Topics include high-order curvature compensation, modified differential pair configurations, and energy-efficient solutions for integrated energy harvesting. These advancements enhance precision and reliability in low-voltage circuits, paving the way for sustainable, low-power electronics and compact devices in the modern digital landscape. It emphasizes the importance of benchmarking different designs against criteria such as power consumption, line regulation, temperature stability, and supply voltage rejection ratio (PSRR). The paper include insights into the state-of-the-art sub-1V voltage reference designs, identification of design trade-offs, and recommendations for future research directions. It underscores the importance of continuous innovation in voltage reference design to address the evolving requirements of ultra-low power electronics. The study here is setting the stage for a detailed analysis of the latest developments in sub-1V voltage references.
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Kraft, Ulrike, Mark Nikolka, Ging‐Ji Nathan Wang, Yeongin Kim, Raphael Pfattner, Maryam Alsufyani, Iain McCulloch, Boris Murmann, and Zhenan Bao. "Low-voltage polymer transistors on hydrophobic dielectrics and surfaces." Journal of Physics: Materials 6, no. 2 (March 2, 2023): 025001. http://dx.doi.org/10.1088/2515-7639/acb7a1.
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Abstract A set of unique features, including large-area solution processing on flexible and stretchable substrates, make polymer semiconductors a promising material choice for a range of state-of-the-art applications in electronics, optoelectronics and sensing. Yet, an inherent weakness of polymer semiconductors remains their low dielectric constants, increasing their susceptibility toward unscreened dipoles. These dipoles are particularly prevalent at polymer-dielectric interfaces with high-k dielectrics, which are essential for the operation of devices such as low-voltage field-effect transistors. This shortcoming can be addressed by using self-assembled monolayers (SAMs) to passivate surfaces that impact charge transport. However, SAM-treatment also increases the hydrophobicity of surfaces and therefore poses a challenge for subsequent solution processing steps and complex packaging of devices. Here, we report low-voltage polymer transistors processed by spin coating of the polymer semiconductors on highly hydrophobic SAM-treated aluminum and hafnium oxide dielectrics (contact angles >100) through fine-tuning of the interfacial tension at the polymer-dielectric interface. This approach enables the processing and detailed characterization of near-amorphous (indacenodithiophene-cobenzothiadiazole) as well as semicrystalline (poly(2,5-bis(2-octyldodecyl)-3,6-di(thiophen-2-yl)diketopyrrolo[3,4-c]pyrrole-1,4-dione-alt-thieno[3,2-b]thiophen)) polymer semiconductors. We demonstrate polymer transistors that exhibit high on-currents and field-independent, charge carrier mobilities of 0.8 cm2 V−1s−1 at low operating voltages (<3 V).
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Kartheek, Palagiri. "Implementation of Modified folded Cascode OTA in Different Biasings Voltages." Journal of University of Shanghai for Science and Technology 24, no. 03 (March 10, 2022): 135–39. http://dx.doi.org/10.51201/jusst/22/0164.
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This paper presents an optimized methodology to modified folded Cascode operational trans conductance amplifier (OTA) design. The design is done in different regions of operation, weak inversion, strong inversion and moderate inversion using the gm/ID methodology in order to optimize MOS transistor sizing. This new family of OTA designs is suitable for biomedical and healthcare circuits and systems, due to the high energy-efficiency, improved gain and low level of noise contribution, when compared to the stateof- the-art in this field. In this paper, two fully-differential implementations are presented, a first one with a double CMOS branch biased by two pairs of voltage-combiners structures in both NMOS and PMOS configurations, and a second one with folded voltagecombiners specifically targeting low voltage applications. The folded voltage-combiners biased OTA is able to operate correctly under a voltage supply down to 0.7 V with proper DC biasing. The simulation is performed in HSPICE Synopsys Tool and compared with existing designs.
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Lademann, Helmut, Gilles Tremblay, Georges Simard, Jacques Dubois, and Said Berriah. "(Invited) Single Cell Voltages for Safety, Predictive Maintenance, and Process Optimization of Industrial Scale Bipolar Electrolyzers (Learned Lessons From Over 30 Years Experience in Chlor-Alkali-Electrolysis)." ECS Meeting Abstracts MA2023-01, no. 36 (August 28, 2023): 1974. http://dx.doi.org/10.1149/ma2023-01361974mtgabs.
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Just like the membrane electrolysis process in the Chlor-Alkali industry 30 years ago, water electrolysis is facing a major transformation from a niche technology to become a global commodity business. 30 years ago, the unique risks of big bipolar electrolyzers were not recognized by the industry. Lessons learned from incidents and near misses led R2 to the development of the EMOS® Safety System: the state-of-the-art single cell voltage-based safety instrumented system for bipolar electrolyzers. Today, the EMOS® Safety System has become a standard in the Chlor-Alkali industry. With plans announced for much larger electrolyzers and several times higher current densities and their increasing risks, water electrolysis should be spared this painful learning process. Fortunately, EMOS® Safety System supports also bipolar water electrolyzers. Short circuits, separator failures etc. can be only detected with single cell current-voltage-curves to turn the power supply off before explosive gas reaches areas with dangerous high gas holdup. Same time the single cell voltages are used to detect any abnormal cell aging as early as possible and to correlate it with the operating conditions. For this purpose, automatically during the electrolyzer startup a neural network is trained to predict the cell voltages afterwards in real-time and to alarm already a deviation of a few mV from the measured cell voltage. Together with KPI’s like U0 and k, automatically calculated by analyzing load changes from normal electrolyzer operation for each cell, predictive maintenance, cell performance specific replacement and process optimization is possible, customized for the individual industrial plant. Examples from industrial scale electrolyzers concerning safety, maintenance and performance optimization will be presented.
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Prasad, P. Siva, Ch N. Narasimha Rao, G. Durga Sukumar, and M. Sushama. "Voltage Analysis of Multilevel Diode Clamped Inverter with SVPWM Technique for Energy Storage Management." Journal of New Materials for Electrochemical Systems 25, no. 2 (June 10, 2022): 135–41. http://dx.doi.org/10.14447/jnmes.v25i2.a07.
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The quantity of direct current voltage steps that are needed by the inverter connect is characterized based on the quantity of levels in an inverter bridge to accomplish a specific electric potential at its output. The best technique for settling the voltages applied to the gadgets is by clipping therefore utilizing dc voltage sources or huge capacitors, which momentarily act as voltage sources. Multilevel topology dependent on specific guideline, the input voltages applied to the devices can be controlled and restricted. A benefit of multilevel inverters contrasted that the yield voltage spectra are altogether better performed. Henceforth, the yield potentials can be sifted with more modest responsive segments, and furthermore, the exchanging frequencies of the gadgets can be diminished. Two advantages with the capacity to manage higher voltage levels present on multilevel inverters is a vital job in the field of high quality produced wave form applications. In this paper, the three levels Diode-clamped inverter incorporates displaying, recreation, plan execution, and examination. Space Vector Balance will be utilized, to dispose of the basic mode electric potentials by exchanging between the various states.
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Fanciulli, Marco, Michele Perego, Caroline Bonafos, A. Mouti, S. Schamm, and G. Benassayag. "Nanocrystals in High-k Dielectric Stacks for Non-Volatile Memory Applications." Advances in Science and Technology 51 (October 2006): 156–66. http://dx.doi.org/10.4028/www.scientific.net/ast.51.156.
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The possibility to use semiconducting or metallic nanocrystals (ncs) embedded in a SiO2 matrix as charge storage elements in novel non volatile memory devices has been widely explored in the last ten years. The replacement of the continuous polysilicon layer of a conventional flash memory device by a 2-dimensional nanoparticle array presents several advantages but the fundamental trade-off between programming and data retention characteristics has not been overcome yet. The main problem is the limited retention time basically due to charge loss by leakage current through the ultra-thin SiO2 tunnelling dielectric. A longer retention time can be achieved by increasing the tunnel oxide thickness. This however implies higher operating voltages and consequently a reduced write/erase speed. Using high-k materials for tunnel and/or gate oxide it is in principle possible to achieve the goal of a low voltage non volatile memory device. The high dielectric constant of these materials allows using thicker tunnel oxide reducing leakage current. Several approaches have been explored to synthesise ordered arrays of ncs in SiO2 but the transfer of these methodologies to the synthesis of 2-d array of ncs in high-k materials is not trivial. In this work we address the material science issues related to the synthesis of metallic and semiconducting ncs in high-k materials using different techniques. A detailed review of the state of the art in the field is presented and further research strategies are suggested.
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Bagherizadeh, Mehdi, Mona Moradi, and Mostafa Torabi. "Designing a Novel High Performance Four-to-Two Compressor Cell Based on CNTFET Technology for Low Voltages." International Journal of Electrical and Computer Engineering (IJECE) 8, no. 6 (December 1, 2018): 4863. http://dx.doi.org/10.11591/ijece.v8i6.pp4863-4870.
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<p>Compressor cell is often placed in critical path of multiplier circuits to perform partial product summation. Therefore it plays a significant role in determining the entire performance of multiplier and digital system. Respecting to the necessity of low power design for portable electronic, designing a low power and high performance compressors seems to be a good solution to overcome of these problems for computations. In this paper a novel high performance four-to-two compressor cell is proposed using Carbon Nanotube Field Effect Transistors (CNTFETs) technology. The new cell is based on Majority Function, NOR, and NAND gates. The main advantage of proposed design in comparison with former cells is the ease of obtaining CARRY output by means of Majority function. Simulations have been done with 32nm technology node using Synopsys HSPICE software. Simulation results confirm the priority of the proposed cell compared to other state-of-the-art four-to-two compressor cells.</p>
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UEDA, TETSUZO, YASUHIRO UEMOTO, TSUYOSHI TANAKA, and DAISUKE UEDA. "GaN TRANSISTORS FOR POWER SWITCHING AND MILLIMETER-WAVE APPLICATIONS." International Journal of High Speed Electronics and Systems 19, no. 01 (March 2009): 145–52. http://dx.doi.org/10.1142/s0129156409006199.
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We review our state-of-the-art GaN -based device technologies for power switching at low frequencies and for future millimeter-wave communication systems. These two applications are emerging in addition to the power amplifiers at microwave frequencies which have been already commercialized for cellular base stations. Technical issues of the power switching GaN device include lowering the fabrication cost, normally-off operation and further increase of the breakdown voltages extracting full potential of GaN -based materials. We establish flat and crack-free epitaxial growth of GaN on Si which can reduce the chip cost. Our novel device structure called Gate Injection Transistor (GIT) achieves normally-off operation with high enough drain current utilizing conductivity modulation. Here we also present the world highest breakdown voltage of 10400V in AlGaN / GaN HFETs. In this paper, we also present high frequency GaN -based devices for millimeter-wave applications. Short-gate MIS-HFETs using in-situ SiN as gate insulators achieve high fmax up to 203GHz. Successful integration of low-loss microstrip lines with via-holes onto sapphire enables compact 3-stage K -band amplifier MMIC of which the small-signal gain is as high as 22dB at 26GHz. The presented devices are promising for the two future emerging applications demonstrating high enough potential of GaN -based transistors.
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Riba, Jordi-Roger, Manuel Moreno-Eguilaz, and Santiago Bogarra. "Tracking Resistance in Polymeric Insulation Materials for High-Voltage Electrical Mobility Applications Evaluated by Existing Test Methods: Identified Research Needs." Polymers 15, no. 18 (September 10, 2023): 3717. http://dx.doi.org/10.3390/polym15183717.
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With the increasing electrification of the transportation and mobility sectors, polymer insulation materials are inevitably exposed to harsher environments, including exposure to contamination, wide temperature ranges, operation at higher voltages and switching frequencies, and low-pressure environments. This paper reviews the tests to characterize the polymeric materials used in insulation systems for electric mobility applications, focusing on resistance to tracking. This paper also reports on the limitations of existing standard test methods and identifies the challenges and research needs to meet the increasing demands of the electric mobility industry. To this end, an evaluation of the scientific and technological state of the art is carried out through the analysis of theses, research articles, technical reports, manufacturers’ datasheets, international standards, and white papers.
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Sandupatla, Abhinay, Subramaniam Arulkumaran, Ng Geok Ing, Shugo Nitta, John Kennedy, and Hiroshi Amano. "Vertical GaN-on-GaN Schottky Diodes as α-Particle Radiation Sensors." Micromachines 11, no. 5 (May 20, 2020): 519. http://dx.doi.org/10.3390/mi11050519.
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Among the different semiconductors, GaN provides advantages over Si, SiC and GaAs in radiation hardness, resulting in researchers exploring the development of GaN-based radiation sensors to be used in particle physics, astronomic and nuclear science applications. Several reports have demonstrated the usefulness of GaN as an α-particle detector. Work in developing GaN-based radiation sensors are still evolving and GaN sensors have successfully detected α-particles, neutrons, ultraviolet rays, x-rays, electrons and γ-rays. This review elaborates on the design of a good radiation detector along with the state-of-the-art α-particle detectors using GaN. Successful improvement in the growth of GaN drift layers (DL) with 2 order of magnitude lower in charge carrier density (CCD) (7.6 × 1014/cm3) on low threading dislocation density (3.1 × 106/cm2) hydride vapor phase epitaxy (HVPE) grown free-standing GaN substrate, which helped ~3 orders of magnitude lower reverse leakage current (IR) with 3-times increase of reverse breakdown voltages. The highest reverse breakdown voltage of −2400 V was also realized from Schottky barrier diodes (SBDs) on a free-standing GaN substrate with 30 μm DL. The formation of thick depletion width (DW) with low CCD resulted in improving high-energy (5.48 MeV) α-particle detection with the charge collection efficiency (CCE) of 62% even at lower bias voltages (−20 V). The detectors also detected 5.48 MeV α-particle with CCE of 100% from SBDs with 30-μm DL at −750 V.
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Lee, Choongkeun, Taegun Yim, and Hongil Yoon. "A Negative Charge Pump Using Enhanced Pumping Clock for Low-Voltage DRAM." Electronics 9, no. 11 (October 26, 2020): 1769. http://dx.doi.org/10.3390/electronics9111769.
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As the supply voltage decreases, there is a need for a high-speed negative charge pump circuit, for example, to produce the back-bias voltage (VBB) with high pumping efficiency at a low supply voltage (VDD). Beyond the basic negative charge pump circuit with the small area overhead, advanced schemes such as hybrid pump circuit (HCP) and cross-coupled hybrid pump circuits (CHPC) were introduced to improve the pumping efficiency and pump down speed. However, they still suffer from pumping efficiency degradation, low level |VBB|, and small pumping currents at very low VDD. A novel negative charge pump using an enhanced pumping clock is proposed. The proposed cross-coupled charge pump consists of the enhanced pumping clock generator (ECG) having a pair of inverters and PMOS latch circuit to produce an enhanced control signal with a greater amplitude, thereby working efficiently especially at low supply voltages. The proposed scheme is validated with a HSPICE simulation using the TSMC 180 nm process. The proposed scheme can be operated down to VDD = 0.4 V, and |VBB|/VDD is obtained to be 86.1% at VDD = 0.5 V and Cload = 20 nF. Compared to the state-of-the-art CHPC scheme, the pumping efficiency is larger by 35% at VDD = 0.6 V and RL = 10 KΩ, and the pumping current is 2.17 times greater at VDD = 1.2 V and VBB = 0 V, making the circuit suitable for very low supply voltage applications in DRAMs.
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Gisslander, Ulf, and Mietek Bakowski. "(Invited) Benchmarking of Beyond the State-of-the-Art Vertical GaN Devices." ECS Meeting Abstracts MA2023-02, no. 35 (December 22, 2023): 1675. http://dx.doi.org/10.1149/ma2023-02351675mtgabs.
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In this paper theoretical benchmarking of semi-vertical and vertical gallium nitride (GaN) MOSFETs with rated voltage of 1.2 kV to 3.3 kV is performed against corresponding silicon carbide (SiC) devices. Specific design features and technology requirements for realization of high voltage vertical GaN MOSFETs are discussed and implemented in simulated structures. The main findings are that a) specific on-resistance of vertical GaN devices is expected to be 75% and 40% of that for 1.2 kV and 3.3 kV SiC MOSFETs, respectively, b) semi-vertical GaN do not offer any advantage over SiC MOSFETs for medium and high voltage devices (>1.0 kV), and c) vertical GaN has largest potential advantage for high and ultra-high voltage devices (>2.0 kV). Gallium nitride (GaN) devices experience an explosive and rapid development with new device providers entering the market at an impressive speed. However, the devices are HEMT (High Electron Mobility Transistor) type lateral devices utilizing the two-dimensional electron gas (2DEG) properties of the GaN/AlGaN interface. The required GaN layers in the devices are grown epitaxially on hetero substrates like Si, SiC, sapphire and poly-AlN using buffer layers to control the strain caused by lattice mismatch which prevents the vertical current flow. For power applications the lateral current flow close to the surface leads to thermal limitations and complicates thermal management in packaging. Furthermore, it leads to large footprint of the devices for large currents. The devices also lack the robust avalanche breakdown characteristics. At present the HEMT power devices are limited to operational voltages of less than 650V with some first devices from VisIC and iGaNPower demonstrating 1200V capability. For these reasons there is an interest in the development of vertical GaN devices opening the possibilities of small footprint and thus lower cost due to smaller chip sizes, high power densities and robust avalanche breakdown characteristics with large avalanche energy capability [1]. The development of vertical devices has been hindered by the lack of large area freestanding GaN substrates facilitating homoepitaxial growth of drift layers. An alternative are semi-vertical structures grown on Si which are the subject of this study along with true vertical structures on GaN. In addition to the material issues there are technological issues that require further attention like dopant compensation and activation and Mg implantation technology for junction termination. This paper focuses on prospective benchmarking of semi-vertical and vertical GaN MOSFETs against SiC devices. A beyond the state-of-the-art benchmarking, in wide voltage range, is missing in the literature. Most of the benchmarking publications report results of experimental structures based on state-of-the-art technology and simple junction termination [2], [3], [4]. The main objective of the work has been to design competitive semi-vertical and vertical GaN structures and perform benchmarking against SiC devices in the voltage range 1.2 kV to 3.3 kV. The structures have been characterized by calculating the output, transfer and voltage blocking characteristics using default Sentaurus models. In the next step, the structures have been modified based on the experience and know-how from SiC devices. The electric field crowding occurring at the trench gate corners must be mitigated both with respect to the breakdown voltage in the bulk material and the reliability of the gate dielectric [5]. Efficient junction termination (JT) is also necessary for both types of structures. This is especially important in the semi-vertical structures where junction termination is an integral part of each device segment and has a significant impact on the resulting on-state resistance. The structure design was optimized by reducing the cell pitch and introducing a multi-cell-per-device-segment design in semi-vertical structures to improve the on-resistance. Removal of the performance limitations in the structures based on the state-of-the-art GaN technology and device cell optimization was done to make benchmarking with more mature SiC devices based on the prediction of what may become feasible beyond the state-of-the-art. 1. Matteo Meneghini et al., Journal of Applied Physics, vol. 130, p. 181101, 2021. 2. Oka, T. Ina, Y. Ueno and J. Nishii, 2019 31st International Symposium on Power Semiconductor Devices and ICs (ISPSD), pp. 303-306, 2021. 3. A. Khadar, C. Liu, R. Soleimanzadeh and E. Matioli, IEEE Electron Device Letters, vol. 40, no. 3, pp. 443-446, 2019. 4. Wei He et al., Nanoscale Research Letters, 17:14, 2022. 5. Nakamura et al., 2011 International Electron Devices Meeting, pp. 26.5.1-26.5.3, 2011.
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Poches, Christopher, Amir Abdul Razzaq, Haiden Studer, Xuguang Li, Krzysztof Pupek, and Weibing Xing. "High Voltage Electrolytes to Stabilize Ni-Rich Lithium Battery Performance." ECS Meeting Abstracts MA2022-02, no. 3 (October 9, 2022): 188. http://dx.doi.org/10.1149/ma2022-023188mtgabs.
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State-of-the-art (SOA) lithium-ion (Li-ion) batteries are approaching their specific energy density limit (~250 Wh kg−1).1 Layered structured, nickel-rich (Ni-rich or high Ni content) lithium transition metal oxides, e.g., LiNi0.8Mn0.1Co0.1O2 (NMC811), have attracted great interests2 owning to their practically deliverable high specific capacity >200 mAh/g. Coupled with high average discharge voltages (~4V vs. Li/Li+), Ni-rich cathode-based lithium batteries possess a great potential to achieve much higher specific energies, e.g., >350 Wh/kg at cell level targeted for electric drive vehicles,3 than SOA Li-ion batteries. In addition, Ni-rich oxides are economically viable as low-cost battery cathode materials due to their low cobalt content. However, Ni-rich cathode-based Li-ion batteries exhibit a quick capacity degradation upon cycling particularly at high charge cutoff voltages (e.g., 4.5V vs. Li/Li+) and at elevated temperatures. Possible degradation mechanisms of Ni-rich based Li cells include structural changes of the material (large c-axis shrinkage at high potentials)4 and parasitic reactions that arise from the interactions between the electrolytes and highly reactive delithiated cathode surface (due to high oxidation state Ni4+ ions).5,6 Therefore, R&D efforts are needed to tackle technical challenges facing the Ni-rick based Li batteries before they become commercially viable. We will present our efforts of developing high voltage electrolytes to afford stable electrochemical performance of Ni-rich cathode-based Li cells. Figure 1 shows the electrochemical performance of NMC-811 cathode, paired Li metal anode, in conventional Li-ion battery electrolyte (Baseline electrolyte) and the high voltage electrolyte developed in this study, evaluated at C/4 rate during the formation and 1 C rate during cycling, between 2.5V and 4.5V, at room temperature. The cell with the high voltage electrolyte maintained ~80% capacity retention after 400 cycles. In contract, the cell with the baseline electrolyte experieced a large capacity fade with only ~25% capacity retention after 400 cycles. The superior cycle stability of the high votage electrolyte, Ni-rich based cell is attributed to the inharently high-voltage stable, multi-functional. Electrolyte chemical structures and their correlation with the electrochemical stability will be discussed. References Chen, W.; Lei, T.; Qian, T.; Lv, W.; He, W.; Wu, C.; Liu, X.; Liu, J.; Chen, B.; Yan, C.; Xiong, J., Advanced Energy Materials 2018, 8 (12). Jiang, M.; Danilov, D. L.; Eichel, R.-A.; Notten, P. H. L., Advanced Energy Materials 2021, 11 (48), 2103005. Gomez‐Martin, A.; Reissig, F.; Frankenstein, L.; Heidbüchel, M.; Winter, M.; Placke, T.; Schmuch, R., Advanced Energy Materials 2022, 12 (8). Cho, D.-H.; Jo, C.-H.; Cho, W.; Kim, Y.-J.; Yashiro, H.; Sun, Y.-K.; Myung, S.-T., Journal of The Electrochemical Society 2014, 161 (6), A920-A926. Chen, C. H.; Liu, J.; Amine, K., Journal of Power Sources 2001, 96 (2), 321-328. Li, J.; Downie, L. E.; Ma, L.; Qiu, W.; Dahn, J. R., Journal of The Electrochemical Society 2015, 162 (7), A1401-A1408. Acknowledgement This material is based upon work supported by the Naval Air Warfare Center Weapons Division, China Lake, CA under Contract No N6893622C0017. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Naval Air Warfare Center Weapons Division, China Lake, CA. Figure 1
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MORGAN, ROBERT A. "HIGH-PERFORMANCE, PRODUCIBLE VERTICAL-CAVITY LASERS FOR OPTICAL INTERCONNECTS." International Journal of High Speed Electronics and Systems 05, no. 04 (December 1994): 593–623. http://dx.doi.org/10.1142/s0129156494000243.
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In this paper we review the state-of-the-art performance of producible, 850 nm, current-guided GaAs/AlGaAs , top-emitting vertical cavity surface emitting lasers (VCSELs). We discuss the motivation and desired characteristics for pursuing VCSELs, particularly in the area of high speed optical data links. We demonstrate that this structure is indeed producible and reproducible using MOVPE, where exceptional uniformity across wafers and arrays is obtained from commercial chambers. Record performance is also reported using MOVPE-grown GaAs VCSELs. These records include submilliamp (0.68 mA) CW room temperature threshold currents, <1.6 V threshold voltages, over 28% total wall-plug efficiency, over 59 mW of (unbonded) power, 200° C lasing, operation over a 100 nm wavelength regime, and other records that rival or exceed those obtained even from strained-layer InGaAs VCSELs of any structure. We also present novel extensions of this base VCSEL platform for lateral mode control, illustrating the flexibility and extendibility of this technology. Finally application of these arrays as 32-channel-wide Opto-Electronic Technology Consortium (OETC) parallel links are shown with error free operations up to 700 Mbits/s (Manchester coded) through 100 m of fiber.
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Dorsch, Philipp, Toni Bartsch, Florian Hubert, Heinrich Milosiu, and Stefan Rupitsch. "Implementation and Validation of a Two-Stage Energy Extraction Circuit for a Self Sustained Asset-Tracking System." Sensors 19, no. 6 (March 16, 2019): 1330. http://dx.doi.org/10.3390/s19061330.
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We present a two-stage energy extraction circuit for a piezoelectric energy harvester, powering an asset-tracking system. Exploiting accelerations generated by many logistic transport devices, e.g., pushcarts, forklifts, assembly belts or cars, we are able to harvest sufficient electrical energy to transmit radio signals, which will allow to track an object when it is moving. Accelerations in logistic applications are non-sinusoidal and lead to high open-circuit voltages, which demand a special adaption of the energy extraction network. We evaluate the performance of several state-of-the-art energy extraction networks and compare those to the performance of our two-stage approach under various excitation conditions. By using the proposed energy extraction circuit, the transmission rate could be increased from four to six transmissions per second for sinusoidal excitations with an open-circuit-voltage of 60 V . In the practical use-case, the two-stage energy extraction network performs more than two times better compared to the one-stage and synchronized switching harvesting with inductor approach.
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Solanki, Jitendra, Norbert Fröhleke, Joachim Böcker, Andreas Averberg, and Peter Wallmeier. "High‐current variable‐voltage rectifiers: state of the art topologies." IET Power Electronics 8, no. 6 (June 2015): 1068–80. http://dx.doi.org/10.1049/iet-pel.2014.0533.
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Chen, Zejie, Sam Keene, William Gaieck, Gabriel S. Phun, Robert Stinson, William D. H. Stinson, Yinxian Wang, et al. "Optimization of Z-Scheme Photocatalytic Reactors for Solar Water Splitting." ECS Meeting Abstracts MA2022-02, no. 48 (October 9, 2022): 1869. http://dx.doi.org/10.1149/ma2022-02481869mtgabs.
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The U.S. Department of Energy recently announced its first Energy Earthshot on Clean Hydrogen, with a cost target of $1/kg-H2 by 2031. Assuming future utility-scale grid electricity prices from photovoltaics ($0.02/kWh), 80% of the cost of H2 would come from performing low-temperature water electrolysis at its thermoneutral voltage, with zero additional overpotential. This fact motivates alternative, less-expensive means of using light to generate mobile charge carriers than photovoltaics, and reactor designs with exceedingly low capital costs, like those we recently invented. Systems using low capital cost reactors benefit from low-voltage operation, which represents a paradigm shift from current state-of-the-art electrolyzers that aim to operate at high current densities. Analytical models predict that solar photocatalytic water splitting inherently operates at low voltages through use of an ensemble of optically thin photoabsorbers each operating at a low rate. Collectively the ensemble exhibits larger overall solar-to-hydrogen conversion efficiencies in comparison to optically thick designs. In efforts to attain these predicted higher efficiencies, we are performing detailed studies on the properties of state-of-the-art doped SrTiO3 and BiVO4 photocatalyst particles. During my talk, I will share our recent efforts in atomic-layer deposited ultrathin oxide coatings to impart redox selectivity and materials stability, single-photocatalyst-particle current–potential behavior and mobile charge carrier properties, and atomic-level information on dopant distributions and materials interfaces obtained from electron microscopies and X-ray spectroscopies. Collectively, our discoveries provide new design guidelines and additional research pathways for the development of effective composite materials to serve as active components in techno-economically viable artificial photosynthetic devices.
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Dusé, Yoann, Fabien Laplace, Nicolas Joubert, Xavier Montmayeur, Noureddine Zitouni, Sebastien Vieusses, Gregory Thepaut, Arnaud Anota, and Gonzalo Picun. "Robust True LDO Linear Voltage Regulator and Digitally Trimmable Buffered Precision Voltage Reference for High-Temperature, Low-Voltage Applications." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2013, HITEN (January 1, 2013): 000096–103. http://dx.doi.org/10.4071/hiten-mp17.
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We present in this paper two new products for high-temperature, low-voltage (2.8V to 5.5V) power management applications. The first product is an original implementation of a monolithic low dropout regulator (XTR70010), able to deliver up to 1A at 230°C with less than 1V of dropout. This new voltage regulator can source an output current level up to 1.5A. The regulated output voltage can be selected among 32 preset values from 0.5V to 3.6V in steps of 100mV, or it can be obtained with a pair of external resistors. The circuit integrates complex analog and digital control blocks providing state of the art features such as UVLO protection, chip enable control, soft start-up and soft shut-down, hiccup short-circuit protection, customer selectable thermal shut-down, input power supply protection, output overshoot remover and stability over an extremely wide range of load capacitances. The circuit offers a fair ±2% absolute accuracy and is guaranteed latch-up free. The second product is an advanced high-temperature, low-power, digitally trimmable voltage reference (XTR75020). Thanks to a custom, 1-wire serial interface, the absolute precision and the temperature coefficient can be adjusted in order to obtain an accuracy better than 0.5% with a temperature coefficient bellow ±20ppm/°C. On-chip OTP memory for trimming of absolute value and temperature coefficient makes the circuit extremely accurate and almost insensitive to drifts over time and temperature. The circuit features a class AB output buffer able to source or sink up to 5mA and remains stable with any load capacitance up to 50μF. The XTR75020 has nine preset possible output voltages. The source and sink short circuit current always remains bellow 25mA. The quiescent current consumption is 300μA typical at 230°C while the standby current is, in all cases, under 20μA. Both devices are designed on a latch-up free silicon-on-insulator process.
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Khan, Sahanowaj, Aritra Acharyya, Hiroshi Inokawa, Hiroaki Satoh, Arindam Biswas, Rudra Sankar Dhar, Amit Banerjee, and Alexey Y. Seteikin. "Terahertz Radiation from High Electron Mobility Avalanche Transit Time Sources Prospective for Biomedical Spectroscopy." Photonics 10, no. 7 (July 10, 2023): 800. http://dx.doi.org/10.3390/photonics10070800.
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A Schottky barrier high-electron-mobility avalanche transit time (HEM-ATT) structure is proposed for terahertz (THz) wave generation. The structure is laterally oriented and based on AlGaN/GaN two-dimensional electron gas (2-DEG). Trenches are introduced at different positions of the top AlGaN barrier layer for realizing different sheet carrier density profiles at the 2-DEG channel; the resulting devices are equivalent to high–low, low–high and low-high–low quasi-Read structures. The DC, large-signal and noise simulations of the HEM-ATTs were carried out using the Silvaco ATLAS platform, non-sinusoidal-voltage-excited large-signal and double-iterative field-maximum small-signal simulation models, respectively. The breakdown voltages of the devices estimated via simulation were validated by using experimental measurements; they were found to be around 17–18 V. Under large-signal conditions, the series resistance of the device is estimated to be around 20 Ω. The large-signal simulation shows that the HEM-ATT source is capable of delivering nearly 300 mW of continuous-wave peak power with 11% conversion efficiency at 1.0 THz, which is a significant improvement over the achievable THz power output and efficiency from the conventional vertical GaN double-drift region (DDR) IMPATT THz source. The noise performance of the THz source was found to be significantly improved by using the quasi-Read HEM-ATT structures compared to the conventional vertical Schottky barrier IMPATT structure. These devices are compatible with the state-of-the-art medium-scale semiconductor device fabrication processes, with scope for further miniaturization, and may have significant potential for application in compact biomedical spectroscopy systems as THz solid-state sources.
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Barros, Luis A. M., António P. Martins, and José Gabriel Pinto. "A Comprehensive Review on Modular Multilevel Converters, Submodule Topologies, and Modulation Techniques." Energies 15, no. 3 (February 1, 2022): 1078. http://dx.doi.org/10.3390/en15031078.
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The concept of the modular multilevel converter (MLC) has been raising interest in research in order to improve their performance and applicability. The potential of an MLC is enormous, with a great focus on medium- and high-voltage applications, such as solar photovoltaic and wind farms, electrified railway systems, or power distribution systems. This concept makes it possible to overcome the limitation of the semiconductors blocking voltages, presenting advantageous characteristics. However, the complexity of implementation and control presents added challenges. Thus, this paper aims to contribute with a critical and comparative analysis of the state-of-the-art aspects of this concept in order to maximize its potential. In this paper, different power electronics converter topologies that can be integrated into the MLC concept are presented, highlighting the advantages and disadvantages of each topology. Nevertheless, different modulation techniques used in an MLC are also presented and analyzed. Computational simulations of all the modulation techniques under analysis were developed, based on four cascaded full-bridge topologies. Considering the simulation results, a comparative analysis was possible to make regarding the symmetry of the synthesized waveforms, the harmonic content, and the power distribution in each submodule constituting the MLC.
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Iov, Florin, Weihao Zhao, and Tamas Kerekes. "Robust PLL-Based Grid Synchronization and Frequency Monitoring." Energies 16, no. 19 (September 28, 2023): 6856. http://dx.doi.org/10.3390/en16196856.
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Nowadays, the penetration of inverter-based energy resources is continuously increasing in low-voltage distribution grids. Their applications cover traditional renewable energy production and energy storage but also new applications such as charging points for electric vehicles, heat pumps, electrolyzers, etc. The power ratings range from a couple of kW to hundreds of kW. Utilities have, in the last few years, reported more challenges regarding power quality in distribution grids, e.g., high harmonic content, high unbalances, large voltage and frequency excursions, etc. Phase-Lock-Loop (PLL) algorithms are typically used for grid synchronization and decoupled control of power converters connected to the grid. Most of the research within PLLs is mainly focusing on grid voltage angle estimation while the byproducts of the algorithms, e.g., frequency and voltage magnitude, are often overlooked. However, both frequency and voltage magnitude estimations are crucial for grid code compliance. Practical considerations for implementation on microcontroller boards of these algorithms are also missing in most of the cases. The present paper proposes a modified PLL algorithm based on a Synchronous Reference Frame that is suitable for both grid synchronization and frequency monitoring, i.e., the estimation of RMS phase voltages and frequencies in highly distorted distribution grids. It also provides the tuning methodology and practical considerations for implementation on commercial DSP boards. The performance of the proposed approach is assessed through simulation studies and laboratory tests under a wide range of operational conditions, showing that the proposed PLL can estimate the grid frequency, for all considered grid events, with an accuracy of less than ±5 mHz, which is a significant improvement on the current state-of-the-art solutions, having an accuracy of at least ±20 mHz or more.
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Lodi Rizzini, Gabriele Lodi, Marco Bassani, Carlo Concari, and Alessandro Soldati. "Exploitation of an Industrial Low-Bandwidth Communication Line for Modulation-Level Synchronization of Voltage Source Converters." Applied Sciences 13, no. 1 (December 24, 2022): 230. http://dx.doi.org/10.3390/app13010230.
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Parallelization of power electronic converter units is a way to meet the high current requirements of modern electrification applications. In case of voltage source converters, parallel operation can be attained only if the voltages of all the units are equal. In the current state of the art, this voltage synchronization can be achieved at the fundamental frequency, but not at modulation frequency, hence requiring bulky filters to limit circulating currents; this lowers the system performance in terms of cost, volume, weight and sustainability. In this paper, the authors propose a novel approach to synchronization, acting directly at the modulation frequency level, thus removing the need for any filter. This technique relies on the natural parasitic inductance and resistance of the wiring among parallel units. Specifically, this paper presents the first of two synchronization stages required to reach the sub-nanosecond synchronization necessary to completely remove the filters. At start-up, a low-bandwidth industrial communication line, based on the CAN protocol, is exploited to guarantee that the error in the synchronization of PWM signals among all the parallel units is lower than 0.1%. This limits the initial circulating current, supporting the subsequent control stage that achieves sub-nanosecond synchronization. The proposed concept is validated by experiments using a commercial MCU unit with an unadorned CAN peripheral.
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Trevisan, Riccardo, and Alessandra Costanzo. "State-of-the-art of contactless energy transfer (CET) systems: design rules and applications." Wireless Power Transfer 1, no. 1 (March 2014): 10–20. http://dx.doi.org/10.1017/wpt.2014.2.
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This paper is dedicated to the extensive review of state-of-the-art contactless energy transfer (CET) systems that are gaining increasing interest in the automatic machinery industries. We first introduce the circuit equivalent networks considered in the literature, and discuss the main operating principles. Possible circuital resonant solutions are also discussed together with the required compensating networks. Then we focus on the problem of transferring, at the maximum efficiency, high-power levels (of the order of 1 kW or higher), showing that highly coupled inductive links are needed, requiring to refrain from the resonance condition. These systems are usually referred to as CET systems, since the link distances are negligible with respect to the coils dimensions. The operating frequencies are of the order of tens to hundreds of kilohertz. The fundamental figures of merit are analytically defined and used to measure the actual limitations involved in this class of systems, including aspects related to realization feasibility with respect to voltages and currents limitations. Finally, state-of-the-art CET works are surveyed, and realistic applications for different operating frequencies are considered and critically compared.
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Disney, Don, Ted Letavic, Tanya Trajkovic, Tomohide Terashima, and Akio Nakagawa. "High-Voltage Integrated Circuits: History, State of the Art, and Future Prospects." IEEE Transactions on Electron Devices 64, no. 3 (March 2017): 659–73. http://dx.doi.org/10.1109/ted.2016.2631125.
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Udrea, F. "State-of-the-art technologies and devices for high-voltage integrated circuits." IET Circuits, Devices & Systems 1, no. 5 (2007): 357. http://dx.doi.org/10.1049/iet-cds:20070025.
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Compton, Jacob, Michael Lain, Meltiani Belekoukia, Valentina Gentili, and Ivana Hasa. "Ethylene Carbonate Free Electrolytes with High Oxidative Stability for High Voltage Lnmo Spinel Cathode in Li-Ion Cells." ECS Meeting Abstracts MA2023-02, no. 2 (December 22, 2023): 202. http://dx.doi.org/10.1149/ma2023-022202mtgabs.
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The increasing implementation of lithium-ion batteries (LIBs) for the fast growing electric vehicle market calls for further improvements in energy density and drives research and innovation to investigate beyond state-of-the-art cell chemistries [1]. Currently, the capacity of the commonly employed transition metal oxide cathodes (NMC series) is approaching their theoretical limit. Thus, to further promote the energy density of LIBs, the most promising strategies are the adoption of a high-voltage spinel LiNi0.5Mn1.5O4 (LNMO) cathode in combination with a high energy density anode. While commercial grades of LNMO are now available, the main challenge toward their implementation is the identification of suitable electrolyte systems with high oxidative stability enabling safe operation of LNMO cathodes at voltages beyond 4.7 V vs Li/Li+, which are also compatible with advanced anode materials operating at low potential. Indeed, electrolytes represent a crucial component in LIBs, and hence a great deal of research has been focusing on the next generation electrolyte systems. These should present a wide electrochemical stability window, high ion conductivity over a wide range of temperature, good thermal stability, and the ability to form stable interphases.[2] In this work we present results on a range of novel electrolytes, based on previous publications [3-5] including super concentrated systems with unconventional solvents to improve the anodic stability, beyond LiPF6 salts to mitigate transition metal dissolution at the cathode, and phosphorous and boron-based additives to improve the stability of the solid/electrolyte interphase (SEI) at the anode. The electrolytes are comprehensively characterised in terms of ionic conductivity over a range of temperatures (see Fig. 1a), viscosity, and thermal stability. Electrochemical impedance spectra (EIS) has been carried out in symmetrical lithium // lithium cells to investigate the interphase stability evolution upon time. Linear sweep voltammetry has been conducted to investigate the anodic stability (see Fig. 1b). The systems have been then investigated in combination with high voltage LNMO cathode, graphite anodes as well as a novel silicon/graphite composite anode. The results will highlight the results achieved so far toward the identification of suitable electrolytes for high energy density Li-ion cells, while discussing the remaining challenges and strategies to mitigate them. [1] Energies 2017, 10(9), 1314, G. Berckmans, M. Messagie, J. Smekens, N. Omar, L. Vanhaverbeke, J. V. Mierlo. [2] Chem. Soc. Rev., 2021, 50, 10486, X. Fan, C. Wang. [3] J. Am. Chem. Soc., 136 (2014) p. 5039, Y. Yamada, K. Furukawa, K. Sodeyama, K. Kikuchi, M. Yaegashi, Y. Takeyama & A. Yamada. [4] Nature Communications, 7 (2016) 12032, J. Wang, Y. Yamada, K. Sodeyama, C. H. Chiang, Y. Tateyama & A. Yamada [5] J. Mater. Sci: Mat. Elec. , 30 (2019) p. 5098, H. Zhou, B. Liu, D. Xia, C. Yin & J. Li Figure 1
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Jia, Hao, Ju-Myung Kim, Peiyuan Gao, and Wu Xu. "(Digital Presentation) Effects of Solvents and Additives in Non-Conventional Liquid Electrolytes for Lithium-Ion Batteries." ECS Meeting Abstracts MA2022-01, no. 2 (July 7, 2022): 193. http://dx.doi.org/10.1149/ma2022-012193mtgabs.
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Lithium (Li)-ion batteries (LIBs) have now been the major power sources in consumer electronic devices and electric vehicles. To further enhance the battery performances, more efforts are required to address significant challenges in improving cycle life, rate capability, energy density, working temperature range and safety of state-of-the-art LIBs. The conventional LiPF6/carbonate electrolytes have been found unable to meet all the requirements for advanced LIBs with high-capacity cathodes and anodes although proper additives can improve the battery performances in certain aspects. For instance, the presence of acidic species like HF in LiPF6 electrolytes and specifically at elevated temperatures is still detrimental to the layered oxide cathodes and the electrode/electrolyte interphases, and the issue of electrochemical oxidation stability of conventional electrolytes at voltages over 4.3 V needs to be addressed for the high-voltage cathodes and batteries. In response to the challenges facing to the conventional LiPF6/carbonate electrolytes in LIBs, especially the long-term cycling stability, non-conventional electrolytes based on functional localized high-concentration electrolytes (LHCEs) have been developed for LIBs in recent years. Due to the unique solvation structures of LHCEs, LHCEs lead to formation of thin, compact and uniform electrode/electrolyte interphases, thus greatly improve LIB performances. In this work, we comparatively studied the effects of solvating solvents and additives in LHCEs on the solvation structures and properties of LHCEs as well as the battery performance of LIBs with nickel-rich cathode and graphite anode. More details will be reported during the presentation.
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Schubert, Martin, Jens Rasche, Mika-Matti Laurila, Tiina Vuorinen, Matti Mäntysalo, and Karlheinz Bock. "Printed Flexible Microelectrode for Application of Nanosecond Pulsed Electric Fields on Cells." Materials 12, no. 17 (August 24, 2019): 2713. http://dx.doi.org/10.3390/ma12172713.
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Medical treatment is increasingly benefiting from biomedical microsystems, especially the trending telemedical application. A promising modality for tumor therapy showed the application of nanosecond pulsed electric fields (nsPEF) on cells to achieve nanoporation, cell death, and other cell reactions. A key technology for this method is the generation of pulsed fields in the nanosecond range with high-field strengths in the range of several kilovolts per centimeter. For further biomedical applications, state-of-the-art setups need to decrease in size and improve their capability of integration into microsystems. Due to demanding electronic requirements, i.e., using high voltages and fast pulses, miniaturization and low-cost fabrication of the electrode is first considered. This paper proposes a proof-of-concept for a miniaturized printed flexible electrode that can apply nsPEF on adherent fibroblast cells. The interdigital gold electrode was printed on polyimide with line-width of about 10 µm using an electrohydrodynamic inkjet printer. Furthermore, an electrical circuit was developed to generate both electrical pulses in the nano-second range and voltages up to 180 V. The electrode was integrated into an experimental setup for in-vitro application to human fibroblasts. Field strengths up to 100 kV/cm with 45 ns pulse duration were applied, depending on the degree of cell confluence. The cells show contraction, detachment from the electrode, and lethal reactions after the nsPEF treatment. Furthermore, this printed miniaturized electrode was found to be suitable for subsequent microsystem integration and further cell experiments to optimize pulse parameters for control of cell reaction and behavior.
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Koch, Daniel, and Sergei Manzhos. "First-Principles Study of the Electrochemical Sodiation of Rutile-Type Vanadium Dioxide." MRS Advances 5, no. 27-28 (2020): 1467–74. http://dx.doi.org/10.1557/adv.2020.70.
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AbstractWe investigate, from first principles, the electrochemical sodiation mechanism of rutile-type vanadium dioxide as a possible electrode material for sodium-ion batteries. The computed voltages versus sodium metal are low in comparison to current state-of-the-art sodium-ion battery cathodes, which we can relate to the large space demand of sodium ions in the compact rutile structure and the resulting severe lattice deformations compared to other working metals. Due to the same reason large anisotropic unit cell volume changes are predicted during cycling. We furthermore find a change of the preferred reaction mechanism during discharge, with a switching between insertion- and conversion-type reaction at higher degrees of sodiation. The predicted capacities on the other hand are appreciable, making a further consideration of this material as high-potential anode in combination with sodium working metal interesting.
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Hwang, D. M., Y. A. Tkachenko, and J. C. M. Hwang. "High-resolution charge collection microscopy with high-voltage electron beams." Proceedings, annual meeting, Electron Microscopy Society of America 52 (1994): 954–55. http://dx.doi.org/10.1017/s0424820100172504.
Full textAbstract:
Electron-beam-induced-current (EBIC) microscopy has the unique capability of simultaneously providing structural and transport characteristics of semiconductors. However, EBIC is traditionally performed inside an SEM with less than 40 keV electron beam energy. As the result, the applications of traditional EBIC for semiconductor device characterization are limited by either probing depth (0.02 ~0.05 μm with 2 ~5 keV electron beams) or spatial resolution (1-2 um with 20 ~40 keV electron beams). To achieve useful resolution for studying the interface effects critical to today's submicron devices, one would have to prepare the samples by either removing the passivation/metallization layers or making cross sections. In this paper, we report a breakthrough in the art of EBIC using high-voltage electron beams (200 keV and higher) to improve the spatial resolution and probing depth simultaneously. Adopting a JEOL 4000FX AEM for EBIC imaging, a spatial resolution of 0.05 um was demonstrated from structures 0.5 um beneath the surface. Using this technique, we have identified a facet degradation mechanism in strained quantum well laser diodes and hot-electroninduced defects in GaAs metal-semiconductor field-effect transistors (MESFETs).
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Jovanović, Uglješa, and Dejan Krstić. "Teslameter for magnetic field measurement in high voltage facilities." Safety Engineering 11, no. 2 (2021): 53–58. http://dx.doi.org/10.5937/se2102053j.
Full textAbstract:
This paper presents a low-cost three-axis teslameter capable of measuring magnetic field intensity in industrial environments and high voltage facilities. It is based on an MFS-3A three-axis magnetic field sensor, and it can measure magnetic flux density up to ±5 mT in all three axes, with accuracy better than ±0.5% and excellent temperature stability. The proposed teslameter was calibrated using a state-of-the-art reference instrument, Helmholtz coil and temperature chamber. The paper describes the development and the calibration of the proposed teslameter. The obtained results are presented as well.
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Gisslander, Ulf, and Mietek Bakowski. "(Invited) Benchmarking of Beyond the State-of-the-Art Vertical GaN Devices." ECS Transactions 112, no. 2 (September 29, 2023): 23–36. http://dx.doi.org/10.1149/11202.0023ecst.
Full textAbstract:
In this paper theoretical benchmarking of semi-vertical and vertical gallium nitride (GaN) MOSFETs with rated voltage of 1.2 kV to 3.3 kV is performed against silicon carbide (SiC) devices. Limitations of the semi-vertical and vertical state-of-the-art GaN structures have been investigated by simulations. Specific design features and technology requirements for realization of high voltage vertical GaN MOSFETs are discussed and implemented in simulated structures. The main modifications to the structures are reduced cell pitch and introduction of electric field shielding implantation and thick oxide at the gate trench bottom and p-type implanted junction termination. The main findings are: (a) specific on-resistance of vertical GaN devices is 75% and 40% of that for 1.2 kV and 3.3 kV SiC MOSFETs, respectively, (b) semi-vertical GaN show no advantage over SiC MOSFETs for medium and high voltage devices over 1 kV, (c) vertical GaN has potential advantage for high and ultra-high voltage devices.
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Fernandez, Daniel, Ann Sebastian, Ethan Ahn, Mahmoud Reda Taha, Samer Dessouky, and Sara Ahmed. "Smart illuminative Charging (SiC) of Future Electric Vehicles Using Roadway Infrastructure." MATEC Web of Conferences 271 (2019): 06006. http://dx.doi.org/10.1051/matecconf/201927106006.
Full textAbstract:
Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways such as mechanical pressure and frictional heat, this paper presents the development and implementation of an innovative charging technique for future electric vehicles (EVs) by fully utilizing the existing roadways and the state-of-the-art nanotechnology. The paper introduces a novel wireless charging system that uses LEDs powered by piezoelectric nanomaterials as the energy transmitter source and thin film solar panels placed at the bottom of the EVs as the receiver, which is then poised to deliver the harvested energy to the vehicle’s battery. The lab-scale prototype device was developed to testify the proposed mechanism of illuminative charging (i.e., “light” couples pavement and vehicle as a wireless energy transfer medium), and the synthesized large-area nanomaterial produced high output voltages of up to 52 mV upon mechanical pressure.
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Quan, Jiale, Zhen Liu, Bo Li, and Jiajun Luo. "Ultra-Low-Power Compact Neuron Circuit with Tunable Spiking Frequency and High Robustness in 22 nm FDSOI." Electronics 12, no. 12 (June 13, 2023): 2648. http://dx.doi.org/10.3390/electronics12122648.
Full textAbstract:
Recent years have seen an increasing popularity in the development of brain-inspired neuromorphic hardware for neural computing systems. However, implementing very large scale simulations of neural networks in hardware is still an open challenge in terms of power efficiency, compactness, and biophysical resemblance. In an effort to design biologically plausible spiking neuron circuits while restricting power consumption, we propose a new subthreshold Leaky Integrate-and-Fire (LIF) neuron circuit designed using 22 nm FDSOI technology. In this circuit, problems of large leakage currents and device mismatch are effectively reduced by deploying the back-gate terminal of FDSOI technology for a tunable design. The proposed neuron is able to operate in two spiking frequency modes with tunable bias parameter setting of key transistors, and it results in complex firing behaviors, such as adaptation, chattering, and bursting, through varying bias voltages. We present circuit post-layout simulation results and demonstrate the biologically plausible neural dynamics. Compared with published state-of-the-art neuron circuits, the circuit dissipates ultra-low energy per spike, on the order of femtojoules per spike, at firing rates ranging from 30 Hz to 1 kHz. Furthermore, the circuit is proven to maintain a good robustness over process variation and Monte Carlo analysis, with relative error 3.02% at a firing rate of approximately 67.1 Hz.
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Hofinger, Jakob, Christoph Putz, Felix Mayr, Katarina Gugujonovic, Dominik Wielend, and Markus C. Scharber. "Understanding the low voltage losses in high-performance non-fullerene acceptor-based organic solar cells." Materials Advances 2, no. 13 (2021): 4291–302. http://dx.doi.org/10.1039/d1ma00293g.
Full textAbstract:
A detailed voltage loss analysis of organic solar cells based on the record breaking material combination D18:Y6 and their fullerene-based counterparts (D18:PC70BM) cast light on the superior performance of state-of-the-art non-fullerene acceptors.
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Chen, Bo, Jin Wu Zhuang, and Chao Zhang. "An Improved Arc Trigger for High Voltage High Current Hybrid Current Limiting Fuse." Advanced Materials Research 546-547 (July 2012): 338–43. http://dx.doi.org/10.4028/www.scientific.net/amr.546-547.338.
Full textAbstract:
With conventional high voltage current limiting fuse, the rated current is usually below 200 A. The rated current of the state of the art arc triggering hybrid current limiting fuse is only 600 A, with its interrupting capability being 25 kA, and still can’t meet the requirements of modern industrial application. With the arc triggering hybrid current limiting fuses, the major obstacle to higher rated current and interrupting capability lies in the long operation time of the arc trigger. Increasing the current density of arc trigger notches can effectively improve the operation speed of the trigger. Simulation and parameter optimization of the arc trigger are conducted by using ANSYS 11.0 to attain the optimal fuse element structure. In this study, the notch current density of the arc trigger was as high as 3300 A/mm2, and the trigger can be used in the hybrid current limiting fuse of rated 35 kV, 2 kA and 40 kA interrupting capability.
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Strüder, L., C. Fiorini, E. Gatti, R. Hartmann, P. Holl, N. Krause, P. Lechner, et al. "High-Resolution High-Count-Rate X-ray Spectroscopy with State-of-the-Art Silicon Detectors." Journal of Synchrotron Radiation 5, no. 3 (May 1, 1998): 268–74. http://dx.doi.org/10.1107/s0909049597014052.
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For the European X-ray multi-mirror (XMM) satellite mission and the German X-ray satellite ABRIXAS, fully depleted pn-CCDs have been fabricated, enabling high-speed low-noise position-resolving X-ray spectroscopy. The detector was designed and fabricated with a homogeneously sensitive area of 36 cm2. At 150 K it has a noise of 4 e− r.m.s., with a readout time of the total focal plane array of 4 ms. The maximum count rate for single-photon counting was 105 counts s−1 under flat-field conditions. In the integration mode more than 109 counts s−1 can be detected at 6 keV. Its position resolution is of the order of 100 µm. The quantum efficiency is higher than 90% from carbon K X-rays (277 eV) up to 10 keV. New cylindrical silicon drift detectors have been designed, fabricated and tested. They comprise an integrated on-chip amplifier system with continuous reset, on-chip voltage divider, electron accumulation layer stabilizer, large area, homogeneous radiation entrance window and a drain for surface-generated leakage current. At count rates as high as 2 × 106 counts cm−2 s−1, they still show excellent spectroscopic behaviour at room-temperature operation in single-photon detection mode. The energy resolution at room temperature is 220 eV at 6 keV X-ray energy and 140 eV at 253 K, being achieved with Peltier coolers. These systems were operated at synchrotron light sources (ESRF, HASYLAB and NLS) as X-ray fluorescence spectrometers in scanning electron microscopes and as ultra low noise photodiodes. The operation of a multi-channel silicon drift detector system is already foreseen at synchrotron light sources for X-ray holography experiments. All systems are fabricated in planar technology having the detector and amplifiers monolithically integrated on high-resistivity silicon.
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Liu, Lianxi, Xufeng Liao, Wenbin Huang, Zhangming Zhu, and Yintang Yang. "Adaptive On-Time-Controlled PFM Boost Converter with a Below-Threshold Startup Voltage." Journal of Circuits, Systems and Computers 27, no. 08 (April 12, 2018): 1850120. http://dx.doi.org/10.1142/s0218126618501207.
Full textAbstract:
A high-efficiency pulse-frequency modulation (PFM) boost DC–DC converter with adaptive on-time (AOT) control method is proposed. A novel three-step startup procedure is proposed and applied on the boost converter, which makes the converter start up with a below-threshold voltage. Besides, adaptive on-time control method can reduce the output ripple dramatically. The proposed integrated boost converter is designed in an SMIC 0.18-[Formula: see text]m standard CMOS process and occupied a chip area of [Formula: see text][Formula: see text]mm2 without any low-[Formula: see text] MOSFETs. In the adopted process, the threshold voltages of PMOS and NMOS are [Formula: see text]0.45[Formula: see text]V and 0.48[Formula: see text]V, respectively. The simulation results show that the proposed converter can start up successfully at the input voltage of 0.25[Formula: see text]V, the output voltage is 1.8[Formula: see text]V with the ripple less than 33[Formula: see text]mV, and the peak efficiency can be up to 94.7%.
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Gruzdev, A. I. "Development of high-capacity lithium-ion battery asstmblies." Electrochemical Energetics 11, no. 3 (2011): 128–35. http://dx.doi.org/10.18500/1608-4039-2011-11-3-128-135.
Full textAbstract:
This paper describes the state-of-the-art and areas of application for lithium-ion batteries. Their competitiveness in comparison with conventional alkaline and acid based batteries is shown. System approaches and circuit configurations used for designing high-capacity energy storage batteries with microprocessor battery managemmt systems (BMS) are considered, including the main functions of BMS. Based on the given examples, the modular design approach of batteries with 2-3 levels of control has been proved. A comparative analysis of different hardware schemes for voltage leveling in storage batteries is carried out.