Structure Based Compact Model for Output Capacitance of Trench Field-Plate MOSFET to Enable Power Loss Prediction

We propose a structure based compact model for out-put capacitance (Coss) of trench Field-Plate MOSFET. Ap-propriate equations were considered for Coss curves in three regions. Output charge (Qoss) and stored energy (Eoss) that were calculated by the proposed model corre-sponded very well to TCAD results. In assumption of 10 A and 2 MHz operation, conduction loss of 1.0 W and out-put charge loss of 1.26 W were estimated.2017 International Conference on Solid State Devices and Materials (SSDM2017), Sendai International Center, Sendai, Japan, September 19-22, 201

Formulation of Single Event Burnout Failure Rate for High Voltage Devices in Satellite Electrical Power System

Single-Event Burnout (SEB) is a catastrophic failure in the high voltage devices that is initiated by the passage of particles during turn-off state. Previous papers reported that SEB failure rate increases sharply when applied voltage exceeds a certain threshold voltage. On the other hand, the high voltage devices for the artificial satellite have been increasing. In space, due to increase flux of particle, it is predicted that SEB failure rate will be higher. In this paper, we proposed the failure rate calculation method for high voltage devices based on SEB cross section and flux of particles. This formula can calculate the failure rate at space level and terrestrial level depending on the applied voltage of the high voltage devices.2017 29th International Symposium on Power Semiconductor Devices and IC\u27s (ISPSD), May 28 2017-June 1 2017, Sapporo, Japa

Proton transfer pathway in anion channelrhodopsin-1

Anion channelrhodopsin from Guillardia theta (GtACR1) has Asp234 (3.2 angstrom) and Glu68 (5.3 angstrom) near the protonated Schiff base. Here, we investigate mutant GtACR1s (e.g., E68Q/D234N) expressed in HEK293 cells. The influence of the acidic residues on the absorption wavelengths was also analyzed using a quantum mechanical/molecular mechanical approach. The calculated protonation pattern indicates that Asp234 is deprotonated and Glu68 is protonated in the original crystal structures. The D234E mutation and the E68Q/D234N mutation shorten and lengthen the measured and calculated absorption wavelengths, respectively, which suggests that Asp234 is deprotonated in the wild-type GtACR1. Molecular dynamics simulations show that upon mutation of deprotonated Asp234 to asparagine, deprotonated Glu68 reorients toward the Schiff base and the calculated absorption wavelength remains unchanged. The formation of the proton transfer pathway via Asp234 toward Glu68 and the disconnection of the anion conducting channel are likely a basis of the gating mechanism

Structure-based capacitance modeling and power loss analysis for the latest high-performance slant field-plate trench MOSFET

Field-plate trench MOSFETs (FP-MOSFETs), with the features of ultralow on-resistance and very low gate–drain charge, are currently the mainstream of high-performance applications and their advancement is continuing as low-voltage silicon power devices. However, owing to their structure, their output capacitance (Coss), which leads to main power loss, remains to be a problem, especially in megahertz switching. In this study, we propose a structure-based capacitance model of FP-MOSFETs for calculating power loss easily under various conditions. Appropriate equations were modeled for Coss curves as three divided components. Output charge (Qoss) and stored energy (Eoss) that were calculated using the model corresponded well to technology computer-aided design (TCAD) simulation, and we validated the accuracy of the model quantitatively. In the power loss analysis of FP-MOSFETs, turn-off loss was sufficiently suppressed, however, mainly Qoss loss increased depending on switching frequency. This analysis reveals that Qoss may become a significant issue in next-generation high-efficiency FP-MOSFETs

Lokiarchaeota archaeon schizorhodopsin-2 (LaSzR2) is an inward proton pump displaying a characteristic feature of acid-induced spectral blue-shift

The photoreactive protein rhodopsin is widespread in microorganisms and has a variety of photobiological functions. Recently, a novel phylogenetically distinctive group named 'schizorhodopsin (SzR)' has been identified as an inward proton pump. We performed functional and spectroscopic studies on an uncharacterised schizorhodopsin from the phylum Lokiarchaeota archaeon. The protein, LaSzR2, having an all-trans-retinal chromophore, showed inward proton pump activity with an absorption maximum at 549 nm. The pH titration experiments revealed that the protonated Schiff base of the retinal chromophore (Lys188, pK(a)=12.3) is stabilised by the deprotonated counterion (presumably Asp184, pK(a)=3.7). The flash-photolysis experiments revealed the presence of two photointermediates, K and M. A proton was released and uptaken from bulk solution upon the formation and decay of the M intermediate. During the M-decay, the Schiff base was reprotonated by the proton from a proton donating residue (presumably Asp172). These properties were compared with other inward (SzRs and xenorhodopsins, XeRs) and outward proton pumps. Notably, LaSzR2 showed acid-induced spectral 'blue-shift' due to the protonation of the counterion, whereas outward proton pumps showed opposite shifts (red-shifts). Thus, we can distinguish between inward and outward proton pumps by the direction of the acid-induced spectral shift

Steady-state data acquisition method for LHD diagnostics

The LHD experiment has gone through 5 campaign periods over the past 4 years, during which the diagnostics data continues to grow and the primary 28 measurements produce about 620 MB/shot in 150 shot/day 3-min cycles. In 2002, 30-min long-pulse experiments will be carried out in LHD, where real-time operations are indispensable for plasma measurements and data acquisition. The new scheme for utilizing conventional CAMAC digitizers in long-pulse experiments has been discussed and examined. As a result, in LHD, CAMACs will shift into 120?180 s cyclic operation, synchronized by the diagnostic timing system. The new CompactPCI-based digitizer frontend has performed about 84 MB/s continuous acquisition in benchmarks, and has been formulated with the conventional CAMAC system to make concurrent acquisitions

Gathering of seven autonomous mobile robots on triangular grids

In this paper, we consider the gathering problem of seven autonomous mobile robots on triangular grids. The gathering problem requires that, starting from any connected initial configuration where a subgraph induced by all robot nodes (nodes where a robot exists) constitutes one connected graph, robots reach a configuration such that the maximum distance between two robots is minimized. For the case of seven robots, gathering is achieved when one robot has six adjacent robot nodes (they form a shape like a hexagon). In this paper, we aim to clarify the relationship between the capability of robots and the solvability of gathering on a triangular grid. In particular, we focus on visibility range of robots. To discuss the solvability of the problem in terms of the visibility range, we consider strong assumptions except for visibility range. Concretely, we assume that robots are fully synchronous and they agree on the direction and orientation of the x-axis, and chirality in the triangular grid. In this setting, we first consider the weakest assumption about visibility range, i.e., robots with visibility range 1. In this case, we show that there exists no collision-free algorithm to solve the gathering problem. Next, we extend the visibility range to 2. In this case, we show that our algorithm can solve the problem from any connected initial configuration. Thus, the proposed algorithm is optimal in terms of visibility range.23rd Workshop on Advances in Parallel and Distributed Computational Models (APDCM2021), May 17, 2021, to be held in conjunction with 35th IEEE International Parallel and Distributed Processing Symposium (IPDPS2021), May 17-21, 2021, Portland, Oregon, US