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关键词： Silicon carbide   MOSFET   Semiconductor device modeling   Mathematical models   Couplings   Load modeling   Logic gates   Electro-thermal behaviors   model   pulsed power   safe operating area (SOA)   silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (mosfet)  

摘要： With the development of high-temperature packaging technology, silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (mosfets) can operate under high-temperature conditions with junction temperatures exceeding 175 degrees C, providing a solution for pulsed power applications facing instantaneous high currents and significant temperature fluctuations. However, the electro-thermal coupling behaviors and safe operating area (SOA) of SiC mosfets in a wide temperature range are unclear, and there is a lack of guiding principles for SiC module packaging and heat dissipation design in pulsed power applications. In this article, an electro-thermal coupling model of SiC mosfet modules is established. The electrical model over a wide temperature range (25 degrees C-375 degrees C) is built in Simulink, and the thermal finite element model is established in COMSOL, while MATLAB script is used to implement interaction between the two models. Then, detailed analyses are conducted on the electro-thermal coupling behaviors of SiC mosfet modules. Besides, the impact of packaging on the SOA of SiC mosfet modules is researched. In addition, a transient junction temperature measurement method of SiC mosfets is proposed by using the on-state resistance R-ds(on) as the temperature-sensitive electrical parameter. Finally, the discharge experiments of the capacitor bank through resistive loads are carried out under short pulse and long pulse, respectively, and the experimental results are consistent with the model.

关键词： Voltage control   Silicon carbide   MOSFET   Hardware   DC-DC power converters   High-voltage techniques   Control systems   Input series output parallel (ISOP) dc-dc converter   improved hardware design   decoupled three-loop control (DTLC)   leader-follower control architecture (LFCA)  

摘要： There is a continuous demand for high power, high frequency, high reliability dc-dc converters in various applications such as medium voltage dc (MVDC) distribution systems, energy storage and electrical vehicle charging facilities. Hence, the input-series-output-parallel (ISOP) dc-dc converter has been widely researched. However, there are a number of challenges with the increase of the input voltage, such as the requirement of high-voltage-isolated and compact high frequency transformers, high reliability and isolated control systems between the high-voltage input side and the low-voltage output side, components selection and design to realize the high efficiency, reliable and effective thermal management, and modular structure design. Therefore, in this article, a 10 kV/400 V ISOP dc-dc converter with eleven dual active bridge (DAB) sub-converters (SCs) based on SiC MOSFETs has been designed to address these challenges, which can satisfy the pursuit for high frequency, high reliability and high efficiency as well as the demand for high voltage isolation and modular structure design. Firstly, the hardware design is presented, which includes the design of the gate driver circuit, high frequency transformer, thermal management, modular structure and the whole prototype. Hence, a high efficiency (97.8%) and large voltage conversion ratio (10 kV/400 V) ISOP-DAB converter has been achieved in this article. Secondly, a decoupled three-loop control (DTLC) based on the leader-follower control architecture (LFCA) has been proposed, which integrates the input voltage sharing control (IVSC) loop, output voltage control (OVC) loop and output current control (OCC) loop. Therefore, effective power sharing, stable output voltage control and flexible output current regulation can be achieved with fast dynamic response. The improved hardware design and the DTLC based on the LFCA have been verified by simulation and experimental results.

关键词： field-effect transistor   gas sensor   MOSFET   TFT   In2O3  

摘要： Excellent stability, low cost, high response, and sensitivity of indium oxide (In2O3), a metal oxide semiconductor, have been verified in the field of gas sensing. Conventional In2O3 gas sensors employ simple and easy-to-manufacture resistive components as transducers. However, the swift advancement of the Internet of Things has raised higher requirements for gas sensors based on metal oxides, primarily including lowering operating temperatures, improving selectivity, and realizing integrability. In response to these three main concerns, field-effect transistor (FET) gas sensors have garnered growing interest over the past decade. When compared with other metal oxide semiconductors, In2O3 exhibits greater carrier concentration and mobility. The property is advantageous for manufacturing FETs with exceptional electrical performance, provided that the off-state current is controlled at a sufficiently low level. This review presents the significant progress made in In2O3 FET gas sensors during the last ten years, covering typical device designs, gas sensing performance indicators, optimization techniques, and strategies for the future development based on In2O3 FET gas sensors.

关键词： Field programmable gate arrays   Standards   Light emitting diodes   Transmitters   Bandwidth   Gain   MOSFET   Visible light communication (VLC)   IEEE 802.15.7   board-to-board (B2B) communication   field programmable gate array (FPGA)   VLC transmitter   intra-box communication  

摘要： Among the several new applications that Visible Light Communication (VLC) have made possible in recent years, board-to-board (B2B) communication represents an important field of employment for this technology. Most of the systems that would benefit from VLC-based B2B communication are digital boards that include Field Programmable Gate Arrays (FPGAs) or advanced processors. Modern FPGA output buffers have limited power, but switch at hundreds of MHz: a much higher rate compared to that of the typical single MOSFET employed in a ON-Off Key (OOK) transmitter. This letter explores the possibility of exploiting the FGPA buffers for realizing a OOK transmitter suitable for B2B communication. A transmitter circuit, driving a 70 mA LED, is proposed and characterized for 26 different electrical standards and configurations of the FPGA buffer. A 210Mb/s link was demonstrated at a distance of 6cm (120Mb/s at 24cm) with a Bit Error Rate (BER) < 1.5 center dot 10(-6) (95% confidence).

关键词： Multichip modules   Heating systems   Substrates   Copper   Inverters   Silicon carbide   Switches   Double-sided cooled (DSC)   integrated power module   low temperature co-fired ceramic (LTCC)   silicon carbide (SiC) power module  

摘要： Double-sided cooled (DSC) power module structures enable high power density for motor drive inverters ideal for electric vehicles (EVs). This work presents a DSC power module using fast-switching 1200 V silicon carbide mosfet devices in a half-bridge topology, with heterogeneous integration of gate control circuitry and condition monitoring. This article describes the module's novel design and a top-down approach to it driven by a prototype inverter for EVs. Highlighted are the specific implementations of the module's key enabling technologies: 1) vertical device-top interconnects in the form of truncated rectangular pyramidal blocks made of copper, enabling maximum heat dissipation;2) a low-temperature cofired ceramic interposer for high mechanical strength and improved electrical isolation;3) built-in gate driver boards;4) embedded temperature sensors. This article also details the module's unique fabrication process, highlighting its good yield and ease of fabrication. Finally, the prototype module is validated using double-pulse tests in a clamped inductive load at full load current and 800-V dc-link voltage.

关键词： SiC MOSFETs   series-connected   voltage equalization   overvoltage  

摘要： A novel clamped voltage equalization strategy is presented for series-connected Silicon Carbide (SiC) Metal-Oxide semiconductor Field-Effect transistors (MOSFETs) in this paper. Differences in device parameters and circuit asymmetry result in the uneven voltage distribution of series-connected SiC MOSFETs, which threatens the safe operation of the circuit. Dynamic voltage equalization is difficult to achieve due to the fast switching speed of SiC MOSFETs. This paper analyzes the switching characteristics and dynamic voltage equalization characteristics of SiC MOSFETs. Based on the analysis, an energy recovery strategy based on the clamping auxiliary circuit is proposed. A 2.8 kW (50 KHz) prototype is fabricated and tested to verify the strategy. Measurement results show that the maximum voltage stress is suppressed from 600 V to less than 320 V in the experimental condition.

关键词： Voltage   Circuits   Turning   Switching circuits   MOSFET   Topology   Degradation   Avalanche transistor   dynamic avalanche   failure analysis   filamentation   Marx-bank generator   semiconductor device modeling  

摘要： Although the Marx bank circuit (MBC) based on the avalanche bipolar junction transistor (ABJT) is widely used in the field of pulse power generators, the main trouble that ABJT triggered by voltage ramp is prone to failure still exists. To explain the obvious reliability differences of ABJTs triggered by voltage ramps of different dV/dt in MBC, the degradation and failure features under a single switching event are analyzed. The normal current path and the leakage current path of the failed device are compared by optical visualization to determine the failure point. A three-dimensional model is established to summarize the voltage ramp triggering conditions and the influence factors. The variations of the current path and the temperature distributions are analyzed by corresponding physical models. The results show that the current path triggered by the slow voltage ramp is easily confined to the device edge due to the insufficient displacement current. The formation of the current filament is related to the way of electron injection and causes the local overheating to damage the main junction. The degraded device completely fails during turning off due to the repeated formations of current filament leading to thermal runaway. The consistency between experimental results and simulations verifies the validity of the explanations. A reference is provided for the optimization of MBC based on ABJT.

关键词： Triboelectricity   Electrodes   MOSFET   Sensors   Zinc oxide   Logic gates   Field effect transistors   Complementary metal-oxide semiconductor (CMOS)   sputtering   triboelectric nanogenerator (TENG)   tribotronics  

摘要： Tribotronics is an original field studying the coupling bet- ween triboelectricity and semiconductors. Contact-electrification field-effect transistors (CE-FETs) have emerged as promising tribotronic devices capable of implementing novel electromechanical devices for human-robot interfacing, sensing platforms, and active flexible electronics in the near future. This letter presents the design, fabrication, and characterization of CE-FETs consisting of a triboel- ectric nanogenerator (TENG)-using zinc oxide and polyethylene terephthalate as tribopositive and tribonegative materials, respecti- vely, coupled to a driven metal-oxide-semiconductor field-effect transistor (mosfet). Optimizing the triboelectric properties of selected materials and operating TENG with frequencies ranging between 2 and 10 Hz and electrode distances ranging from 2 to 10 mm, the modulation of the output characteristics of the mosfet via external mechanical forces has been demonstrated.

关键词： Electromagnetic interference (EMI)   power density   switching oscillation   WPT snubber   Electromagnetic interference (EMI)   power density   switching oscillation   WPT snubber  

摘要： This letter proposes a novel wireless power transfer (WPT)-based snubber circuit aimed to suppress the ringing of SiC mosfet resulting from parasitic impedances in the switching circuit. The key innovation lies in the artful transfer of the ringing energy to an optimally designed receiver via magnetic resonant coupling. It reveals that the oscillation time of switching ringing can be reduced by up to 67%, significantly expanding the upper limit of the switching frequency and reducing electromagnetic interference. Compared to the traditional RC snubber, permissible voltage and energy loss of the WPT snubber is reduced by 87.84% and 86.84%. This technology greatly reduces the sizes of passive components, resulting in a huge enhancement of power density. Finally, both theoretical analyses and experimental results confirm the effectiveness of the proposed system.

关键词： Specific on-resistance   Breakdown voltage   Superjunction   Trench MOSFET   High-K dielectric   4H-SiC  

摘要： This paper proposes a 4H-SiC superjunction trench MOSFET with extended high-K dielectric under metal gate (EHK SJ-TMOS). The characteristics of EHK SJ-TMOS include the use of the high-K (HK) dielectric as the gate dielectric and the extension of the HK dielectric as a deep trench into the N-type drift region. The extended HK trench effectively modulates the electric field distribution in the SJ drift region, which improves the breakdown voltage (BV). The introduction of HK dielectric also assists in depleting the SJ drift region, which enables the drift region of EHK SJ-TMOS to use a higher doping concentration, thereby reducing Ron,sp. Furthermore, the application of high-K gate dielectric alleviates the high gate oxide electric field problem in conventional SiC superjunction trench MOSFETs (SiC SJ-TMOS). The simulation results demonstrate that EHK SJ-TMOS exhibits a 59.2 % reduction in Ron,sp, a 2.4 % increase in BV, and a 156.5 % improvement in the FOM (FOM = BV2/Ron,sp) compared to the SiC SJ-TMOS, indicating enhanced performance.