• Journal of Institute of Control, Robotics and Systems
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• v.18 no.4
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• pp.371-374
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• 2012

DC/DC switching power converters produce DC output voltages from different stable DC input sources regulated by a bi-polar transistor. The converters can be used in regenerative braking of DC motors to return energy back in the supply, resulting in energy savings for the systems containing frequent stops. The voltage mode DC/DC converter is composed of a PWM (Pulse Width Modulation) controller, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an inductor, and capacitors, etc. PWM is applied to control and regulate the total output voltage. It is shown that the output of DC/DC converter depends on the variation of threshold voltage at MOSFET and the variation of pulse width. In the PWM operation, the missing pulses, the changes in pulse width, and a change in the period of the output waveform are studied by SPICE (Simulation Program with Integrated Circuit Emphasis) and experiments.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1291-1293
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• 1998

Power MOSFETs are very important Devices in power circuit applications such as motor control, switch mode power supplies & telecommunicatioelectronics. In order to investigated the Avalanch Energy value of MOSFET due to Misalign. Some samples made under several different $P^+$ misalign and $N^+$ misalign. The relationship between evalanch energy value and misalign is investigated as well in this paper.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.683-686
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• 2003

In this paper, we have investigated electrical characteristics of TRENCH GATE POWER MOSFET in the temperature range of 300K to 500K. The results of this study indicate that on-resistance and breakdown voltage increase with the temperature ,but drain current, threshold voltage and transconductance decrease with the temperature. Especially, it is observed that electrical characteristics are improved as numerical unit cells are increased.

• ETRI Journal
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• v.28 no.2
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• pp.253-256
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• 2006

We propose a novel power metal oxide semiconductor field effect transistor (MOSFET) employing a strained-Si channel structure to improve the current drivability and on-resistance characteristic of the high-voltage MOSFET. A 20 nm thick strained-Si low field channel NMOSFET with a $0.75\;{\mu}m$ thick $Si_{0.8}Ge_{0.2}$ buffer layer improved the drive current by 20% with a 25% reduction in on-resistance compared with a conventional Si channel high-voltage NMOSFET, while suppressing the breakdown voltage and subthreshold slope characteristic degradation by 6% and 8%, respectively. Also, the strained-Si high-voltage NMOSFET improved the transconductance by 28% and 52% at the linear and saturation regimes.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.53-54
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• 2016

본 논문은 전동기 구동용 SiC MOSFET 인버터의 NEMA(National equipment manufacturer's association) 규격 만족을 위한 출력 필터 구조에 따른 영향을 분석한다. 구조와 목적에 따라 정현파 필터와 dv/dt 필터를 적용하여 380V, 60Hz, 3.7kW급 유도 전동기를 대상으로 실험을 수행하여 설계한 필터가 NEMA 규격을 만족시킬 수 있을 뿐만 아니라 전동기 누설전류를 감소시켜 효율까지 향상시킬 수 있음을 확인하였다.

• Transactions on Electrical and Electronic Materials
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• v.17 no.5
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• pp.302-305
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• 2016

In this paper, a low on-resistance and high current driving capability trench gate power metal-oxide-semiconductor field-effect transistor (MOSFET) incorporating a current sensing feature is proposed and evaluated. In order to realize higher cell density, higher current driving capability, cost-effective production, and higher reliability, self-aligned trench etching and hydrogen annealing techniques are developed. While maintaining low threshold voltage and simultaneously improving gate oxide integrity, the double-layer gate oxide technology was adapted. The trench gate power MOSFET was designed with a 0.6 μm trench width and 3.0 μm cell pitch. The evaluated on-resistance and breakdown voltage of the device were less than 24 mΩ and 105 V, respectively. The measured sensing ratio was approximately 70:1. Sensing ratio variations depending on the gate applied voltage of 4 V ~ 10 V were less than 5.6%.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.477-484
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• 2021

The 4kW class inverter for portable ESS designed through this study achieves lightweight and high power density by reducing the volume of passive devices (capacitors, inductors, etc.) suitable for portable use, and minimizes heat loss of the MOSFET through the low on resistance of the MOSFET. So that high efficiency can be achieved. In addition, in order to deliver high quality energy, it is designed to have a low THDV in accordance with the current KEPCO business handling guidelines, and is designed to output a sine wave with low distortion.

• Journal of IKEEE
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• v.22 no.2
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• pp.393-401
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• 2018

In this paper, a rectifier for WPC / A4WP wireless power transmission is designed. The proposed rectifier supports both WPC (Wireless Power Consortium) and A4WP (Alliance For Wireless Power) and is designed with full-bridge rectifier. WPC transmits power at the frequency of 100kHz to 205kHz and A4WP at the frequency of 6.75MHz. Since the bridge rectifier uses a MOSFET instead of a diode, the reverse current flows and the efficiency is affected if the output voltage is higher than the input voltage. Therefore, we added the reverse current detector that detects the current flowing through the MOSFET and shut off the reverse current. The frequency discriminator is used because the rectifier has different frequency band. The proposed rectifier was designed using $0.35{\mu}m$ CMOS high voltage process. The input voltage is up to 18V and the rectifier operates at 100kH to 205kHz, 6.78MHz frequency. The maximum efficiency is 94.8% and the maximum power transfer is 5.78W.

• Journal of Radiation Protection and Research
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• v.31 no.4
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• pp.165-171
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• 2006

In Korea, a real-time effective dose measurement system is in development. The system uses 32 high-sensitivity MOSFET dosimeters to measure radiation doses at various organ locations in an anthropomorphic physical phantom. The MOSFET dosimeters are, however, mainly made of silicon and shows some degree of energy and angular dependence especially for low energy photons. This study determines the correction factors to correct for these dependences of the MOSFET dosimeters for accurate measurement of radiation doses at organ locations in the phantom. For this, first, the dose correction factors of MOSFET dosimeters were determined for the energy spectrum in the steam generator channel of the Kori Nuclear Power Plant Unit #1 by Monte Carlo simulations. Then, the results were compared with the dose correction factors from 0.652 MeV and 1.25 MeV mono-energetic photons. The difference of the dose correction factors were found very negligible $(\leq1.5%)$, which in general shows that the dose corrections factors determined from 0.662 MeV and 1.25 MeV can be in a steam general channel head of a nuclear power plant. The measured effective dose was generally found to decrease bit $\sim7%$ when we apply the dose correction factors.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.6
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• pp.697-705
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• 2014

A single chip Programmable AC to DC Power Converter, consisting of wide band gap SiC MOSFET and SiC diodes, has been proposed which converts high frequency ac voltage to a conditioned dc output voltage at user defined given power level. The converter has high conversion efficiency because of negligible reverse recovery current in SiC diode and SiC MOSFET. High frequency operation reduces the need of bigger size inductor. Lead inductors are enough to maintain current continuity. A complete electrical analysis, die area estimation and thermal analysis of the converter has been presented. It has been found that settling time and peak overshoot voltage across the device has reduced significantly when SiC devices are used with respect to Si devices. Reduction in peak overshoot also increases the converter efficiency. The total package substrate dimension of the converter circuit is only $5mm{\times}5mm$. Thermal analysis performed in the paper shows that these devices would be very useful for use as miniaturized power converters for load currents of up to 5-7 amp, keeping the package thermal conductivity limitation in mind. The converter is ideal for voltage requirements for sub-5 V level power supplies for high temperatures and space electronics systems.