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High-Speed On-Chip signaling: Voltage or Current-Mode?
摘要： In this paper, we investigate several on-chip signaling schemes. Specifically, we compare different voltage-mode (VM) and current-mode (CM) signaling schemes considering power, performance, and robustness. In addition, we propose a new CM signaling scheme that uses a simple NAND-NOR gate transmitter circuit and a current-comparator-based receiver circuit. We implemented each signaling scheme using a 45 nm CMOS technology. The extracted simulation results show that a traditional CM signaling scheme consumes 58–78% less power compared to a traditional buffered VM signaling scheme in the 1–3 GHz frequency range. Our proposed CM signaling scheme consumes up to 95% and 81% lower power compared to buffered VM and existing CM schemes, respectively. In addition, the proposed CM signaling scheme has 37–41% lower latency with similar slew-rates compared to the buffered signaling scheme.
关键词： Voltage-mode,Signaling,Low-power,Low-swing,Interconnect,Current-mode
更新于2025-09-19 17:15:36
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Effect of (102) Diffracted Peak on Magnetic, Photoelectric, and Adhesive Characteristics of Fe <sub/>2</sub> Si Films
摘要： Fe2Si films with thicknesses from 100 nm to 600 nm underwent the following processes; (a) as-deposited films were maintained at room temperature (RT); (b) deposited films were post-annealed at 150 °C for 1 h, and (c) deposited films were post-annealed at a treatment temperature of 250 °C for 1 h. The X-ray diffraction (XRD) patterns of Fe2Si included significant (102) and (200) diffractions with corresponding peaks at 2θ are 44° and 53°, respectively. The (102) diffracted intensity and grain size of thicker and post-annealed Fe2Si thin films exceeded those of thinner and as-deposited Fe2Si thin films. The Fe2Si (102) peak revealed magneto-crystalline anisotropy, which reduced electrical resistivity and was associated with the highest low-frequency alternative-current (ac) magnetic susceptibility (χac). The maximum value of χac was reached at a thickness of 600 nm at the optimal frequency (fres) of 10 Hz, which generated maximized spin sensitivity. The resistivity (ρ) declined as the Fe2Si thickness and post-annealing temperature increased, because grain boundaries and the thin-film surface scattered the electrons. The 600 nm-thick Fe2Si thin film that was post-annealed at 250 °C had the lowest ρ of around 2.1 × 10^4 μΩ·cm. The as-deposited Fe2Si thin film with a thickness of 100 nm had the highest transmittance of approximately 48%. The maximum transmittance decreased slightly as the thickness increased and upon post-annealing. The surface energy of the as-deposited Fe2Si films exceeded those of post-annealed films, revealing that the adhesion of as-deposited Fe2Si films was stronger than that of post-annealed films owing to the degree of crystallinity.
关键词： Adhesion,Magneto Crystalline Anisotropy,Photoelectrical Property,Low-Frequency Alternative-Current Magnetic Susceptibility (χac)
更新于2025-09-19 17:15:36
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In-field dependences of the critical current density J in GdBa2Cu3O7-d coated conductors produced by Zr irradiation and post-annealing at low temperatures
摘要： We report the influence of 6 MeV Zr4+ irradiation and post-irradiation annealing (200 °C) in the in-field dependences of the critical current densities Jc of 1.3 μm thick GdBa2Cu3O7-d coated conductors grown by co-evaporation. Samples were irradiated with 6 MeV Zr4+ and fluences between 2.3 × 10^11 cm^-2 and 3 × 10^12 cm^-2. The correlation between the superconducting critical temperature Tc and in-field dependences of Jc has been analyzed. In addition, random disorder introduced by irradiation was reduced by thermal annealed at 200 °C. The analysis of our experimental findings indicates that the optimal irradiation (reducing random disorder by annealing) results in the suppression of the self-field Jc of ≈10% and in-field Jc enhancements nearly doubled at about 5 T. A clear correlation between Tc, disorder and self-field Jc is observed. Additional random disorder and nanoclusters suppress systematically Tc and increase the flux creep relaxation at intermediate temperatures (reducing the characteristic glassy μ value).
关键词： E. Ion irradiation,A. Coated conductors,D. Critical current densities
更新于2025-09-19 17:15:36
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Optical, electrical and microstructural properties of SiC thin films deposited by reactive dc magnetron sputtering
摘要： In this study, amorphous silicon carbide (SiC) thin films of variable compositions were deposited on Si (100) and glass substrates by reactive direct current magnetron sputtering of high purity silicon target, using CH4 as reactive gas. The composition and the properties of the coatings have been modified by the change in the reactive gas flow rate from 5% to 50%. Spectrophotometer has been used to measure the optical transmittance and reflectance of silicon carbide thin films over the spectral range from 280 to 1000 nm. The optical constants such as refractive indices and the extinction coefficients of the films were calculated. The band gap values of the deposited films were further evaluated with respect to the gas flow rate. Transmittance values of SiC films changed from 85% to almost 0% in the visible light range. The optical band gap values of the films were altered from 1.7 to 2.7 eV. The activation energy was found to increase from 0.16 eV up to 1 eV and dark conductivity decreased from 7.42x10-4 to 1.06x10-9 Ω-1cm-1 while carbon concentration in the films increased. The results demonstrated that the optical and electrical properties of SiC films could easily be tailored by modifying Si and C concentrations in the coating composition, for the same film thicknesses.
关键词： optical properties,microstructural properties,Silicon carbide thin films,electrical properties,reactive direct current magnetron sputtering
更新于2025-09-19 17:15:36
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[IEEE 2018 International conference on Computing, Electronic and Electrical Engineering (ICE Cube) - Quetta, Pakistan (2018.11.12-2018.11.13)] 2018 International Conference on Computing, Electronic and Electrical Engineering (ICE Cube) - Impact of PV Penetration on Short Circuit Current of Radial Distributed Feeder and Existing Power System Protection of NUST
摘要： Integration of distributed generation into existing network can solve the problem of increasing energy demand which is due to exponential growth in world population. Integration of distributed generation has increased due to its immense advantages like low loading of transmission network, improvement in voltage profile and decrease in line losses. Despite of many advantages distributed generation also poses various adverse effects on network like harmonics, network protection, frequency instability and increase in short-circuit current level. However, it is difficult to eliminate the fault behavior due to dispersed nature of distributed generation that might affect the performance of power system protection. This is due to the change in power flow and magnitude of fault current. In this paper the effect of distributed generation on fault current level and protection of radial distribution feeder of National University of Science and Technology is studied. Three phase fault is simulated and analyzed for radial distribution network of National University of Science and Technology in MATLAB Simulink.
关键词： short circuit current,distribution system,three phase fault,PV penetration,MV distributed network,Distributed generation
更新于2025-09-19 17:15:36
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Calculation of the local current density in HTS insulated REBCO coils using a Volume Integral Formulation and its contribution to coils protection
摘要： High Temperature Superconducting materials have remarkable current carrying capabilities even under high magnetic field operating conditions. Since long length of Rare-Earth Barium Copper-Oxide (REBCO) coated conductors are now available thanks to improvements of the fabrication process, these materials have become an attractive option for high field magnet applications. However, such extreme operating conditions require an efficient quench protection system in order to prevent the coil from damaging hot spots, which depends highly on the winding considered. We focus here on insulated HTS coils protection against thermal runaways that can locally destroy the magnet. We developed a transient 2D axisymmetric model using a Volume Integral Formulation based on the generalization of the Partial Element Equivalent Circuit method to compute the local current density distribution inside REBCO insulated coils and accounting for local performance variations. Indeed, integral methods main interesting property is to require to mesh active regions only, which leads to a significant reduction of the problem’s size. The formulation is introduced for general 3D cases and its adaptation to 2D axisymmetric problems is detailed. The formulation has been validated thanks to a bulk magnetization benchmark whose results obtained through Finite Element Method were compared to our integral formulation solution. The model has also been compared to experimental data obtained on a double pancake coil. The objective is to study magnetization effects on the transient voltage due to dynamic current distribution when ramping up the magnet so as to be able to determine some key parameters associated to coil’s protection. Such an approach is developed on a small-scale test case and the transient behaviours observed are discussed.
关键词： Current distribution,HTS insulated coils,Volume Integral Formulation
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE XXVII International Scientific Conference Electronics (ET) - Sozopol (2018.9.13-2018.9.15)] 2018 IEEE XXVII International Scientific Conference Electronics - ET - Improving control of excitation sources in transient and lock-in thermography
摘要： The aim of the paper is to study the possibilities for using one excitation source for transient as well as lock-in infrared thermography modes. Problems in controlling the high-power optical excitation sources in active thermography are analysed. Special attention is paid to high power LEDs as sources for thermal stimulation in thermography. A method for improving control of high-power optical and electrical types of excitation sources is proposed with possibility of voltage or current stabilization.
关键词： active thermography,excitation source,current sensing,multiphase DC/DC converter,power LED
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE SENSORS - New Delhi, India (2018.10.28-2018.10.31)] 2018 IEEE SENSORS - Rectangular Array Current Transducer with Integrated Microfluxgate Sensors
摘要： Novel rectangular yokeless current transducer with the range 400 A using 16 microfluxgate sensors around the busbar conductor is presented in this paper. Compared to yokeless transducers utilizing the differential pair of magnetic sensors, our solution has much better suppression of external currents (lower crosstalk). Compared to industrial transducers with yoke, the new transducer has 10-times lower noise, 10-times better temperature stability, and same crosstalk. Sensor design, different methods for calculating the current and temperature dependence are presented in this paper. Crosstalk error is examined in dependence on the number of the operating sensors and external current position.
关键词： Finite element modelling,current sensor,microfluxgate sensors,rectangular sensor array
更新于2025-09-19 17:15:36
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[IEEE 2017 14th IEEE India Council International Conference (INDICON) - Roorkee (2017.12.15-2017.12.17)] 2017 14th IEEE India Council International Conference (INDICON) - Series and hybrid connection of sediment microbial fuel cell for powering Led
摘要： Sediment microbial fuel cell (SMFC) is a bio-electrochemical device which generates green electricity from microbes. SMFC are projected to be employed as a sustainable power source for lighting and remote environmental observing. To understand the performance of SMFC, experiment performs for one month. Single SMFC has low voltage and current level which is unable to drive electronic devices. To increase power generation from SMFC, eight individual SMFC are connected together either in series or in hybrid connection. Two combinations of this SMFC, hybrid connection, are proving to be the more effective one, step-up both the voltage and current level, mutually. Polarization curve and behavior of voltage generation experiments are done for series and hybrid connected SMFC. The power density is obtained 1.111mW/m2 at 435.25μA from series and 1.309mW/m2 at 870.75μA in hybrid connected SMFC. This study suggests that maximized the power production of SMFC by connecting series and hybrid for practical use of the device.
关键词： SMFC,open circuit voltage(OCV),current,hybrid connection,series connection
更新于2025-09-19 17:15:36
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A High Performance Shade-Tolerant MPPT Based on Current-Mode Control
摘要： This paper proposes a high performance shade-tolerant maximum power point tracking (STMPPT) technique for DC-DC converter stage of photovoltaic (PV) applications. The average current-mode control (ACMC) is utilized to regulate the PV array current using two feedback control loops. The current-mode control is a superior scheme in control of DC-DC power electronic converters. The proposed STMPPT technique operates in two modes. The ACMC with the perturb and observe (P&O) MPPT algorithm functions in a local MPPT (LMPPT) mode under normal irradiance condition. When the PV array is likely to be partially shaded, a global MPPT (GMPPT) subroutine effectively scans the PV profile to optimize the PV system operation. This is achieved by implementing simple innovations to the ACMC-based P&O algorithm. The innovations benefit from useful observations of I-V characteristics. The idea behind using the I-V characteristics is to significantly reduce the search space, make the algorithm independent of shading conditions and PV array configuration, and inherently recognize the occurrence of partial shading conditions (PSCs). The proposed STMPPT technique enables very fast and reliable tracking of global maximum power point (GMPP). In addition, it can stably work under dynamic environmental change without losing correct sense of tracking direction. Its simplicity and independency would offer a viable solution for PV converter products. Simulation and experimental performance assessments are presented under different operating conditions that could happen in outdoor PV installations.
关键词： perturb and observe algorithm,partial shading condition,Photovoltaic system,current-mode control,shade-tolerant maximum power point tracking
更新于2025-09-19 17:15:36