Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 5 Articles
A CMOS controllable constant power generator based on multiplier/divider circuit is presented. It generates constant power for a\nwide range of the resistive loads. For the generated power of 5mW, and the resistance range from 0.5 k�© to 1.5 k�©, the relative error\nof dissipated power is less than 0.6%. For single supply voltage of 5V, presented controllable constant power generator generates\npower from 0.5mWto 7.8mW, for the load resistance dynamic range from 3 up to 15, while the relative error of generated power is\nless than 2%. The frequency bandwidth of the proposed design is up to 5 MHz. Through the detailed analysis of the loop gain, it is\nshown that the circuit has no stability problems....
In this work, DC and transient characteristics of a 4 diode string utilizing\ntriple-well technologies as a VDD-VSS clamp device for ESD protection are\nanalyzed in detail based on 2-dimensional device and mixed-mode simulations.\nIt is shown that there exists parasitic pnp bipolar transistor action in\nthis device leading to a sudden increase in DC substrate leakage if anode bias\nis getting high. Through transient simulations for a 2000 V PS-mode HBM\nESD discharge event, it is shown that the dominant discharge path is the one\nformed by a parasitic pnpn thyristor and a parasitic npn bipolar transistor in\nseries. Percentage ratios of the various current components regarding the\nanode current at its current peaking are provided. The mechanisms involved\nin ESD discharge inside the diode-string clamp utilizing triple-well technologies\nare explained in detail, which has never been done anywhere in the literature\nbased on simulations or measurements....
The paper describes the effect of doping with hydrogen and tungsten by means of plasma-immersion ion implantation (PIII) on\nthe properties of vanadium dioxide and hydrated vanadium pentoxide films. It is shown that the parameters of the metal-insulator\nphase transition in VO2 thin films depend on the hydrogen implantation dose. Next, we explore the effect of PIII on composition,\noptical properties, and the internal electrochromic effect (IECE) in V2O5�nH2O films. The variations in the composition and\nstructure caused by the hydrogen insertion, as well as those caused by the electrochromic effect, are studied by nuclear magnetic\nresonance, thermogravimetry, Raman spectroscopy, and X-ray structural analysis. It is shown that the ion implantation-induced\nhydrogenation can substantially enhance the manifestation and performance of the IECE in V2O5 xerogel films. Finally, the effect\nof PIII-assisted doping with W on the parameters of electrical switching in Au/V2O5�nH2O/Au sandwich structures is examined.\nIt is shown that implanting small tungsten doses improves the switching parameters after forming. When implanting large doses,\nswitching is observed without electro forming, and if electro forming is applied, the switching effect, on the contrary, disappears....
Power consumption of Global Positioning System (GPS) acquisition is a great challenge\nfor energy-constrained applications. In this work, a metric named acquisition mean computation\noverhead is proposed to measure the energy cost. A novel multi-peak double-dwell (MP/DD)\nacquisition method for GPS weak signal is proposed. It adopts multi-peak correlation results as\ncandidates in the first acquisition dwell and selects the largest one as the final acquisition result\nin the second acquisition dwell. Theoretical analysis and numerical simulation are presented in\ndetail. Meanwhile, the very-large-scale integration (VLSI) implementation of coarse- and fine-grained\nacquisition engines applied to the proposed method is done. The detection probability and acquisition\nmean computation overhead are simulated using the Monte-Carlo method, and its mean acquisition\npower is tested with an actual chip. We fabricated the GPS signal acquisition engine with a 40 nm\ncomplementary metal oxide semiconductor (CMOS) process. The simulation results demonstrate\nthat detection probability is promoted from 18% to 67% when signal power is equal to 23 dB/Hz.\nThe acquisition mean computation overhead is reduced greatly by 64%. Measurement results show\nthat the energy consumption of this design is only 21.5% of the conventional double-dwell/maximum\n(DD/MAX) method....
Novel method of boron diffusion at low temperatures between 1150 and 1300Ã?°C is used for the formation of both p-i SiC junction\nand i-region in one technological process. As the junction formation conditions in this method are essentially different from those\nin the conventional diffusion (low temperatures and process of diffusion are accompanied by formation of structure defects), it is\nof special interest to identify advantages and disadvantages of a new method of diffusion. Developed SiC p-i-n junction diodes\nhave fast switching time, and the duration of the reverse recovery current is less than 10 ns with a breakdown voltage of 120ââ?¬â??140V.\nFabricated diodes possess capability to operate at temperatures up to 300Ã?°C. As the temperature of diffusion process is lower than\nthe melting temperature of silicon, this new technology allows fabrication of diodes on the base of SiC/Si epitaxial structures....
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