• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.197-202
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• 2019

A small millimeter-wave tracking radar power supply must provide stable power with minimal ripple noise and the switching frequency noise of the DC-DC converter must have a real-time self-test capability through on-the-fly monitoring without causing false alarms and ghost In this study, we developed a multi-output switching power supply with output power of more than 80% (@ 100% load) and 10 output power by adopting + 28VDC input for application to small millimeter wave tracking radar, DC-DC converter is applied for large power output and multi-output flyback method is applied for the remaining small power output. The test results show that 85% efficiency efficiency is achieved under 100% load condition.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.8
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• pp.24-31
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• 2008

Power converters are becoming an essential block in modem mobile multimedia application. This paper presents a high performance DC-DC buck converter for mobile applications. Controller of DC-DC buck converter is designed by current-mode control method. An current-mode DC-DC converter is implemented in a standard $0.18{\mu}m$ CMOS process, and the overall die size was $1.2mm^2$. The peak efficiency was 86 % with a switching frequency of $1\sim1.5MHz$ and a maximum load current of 400mA.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.152-158
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• 1999

Due to high power ratings and low conduction loss, the TGBT has become more attractive in switching power supplies. However, its lower turn-on and turn-off characteristics than those of MOSFET cause severe switching loss and s switching frequency limitation. This paper proposes 2.4kW. 48V. high efficiency half-bridge DC-DC converter using p paralleled TGBT-MOSFET switch concept to use the merits of TGBTs and MOSFETs. Tn parallel switches. each of I TGBT and MOSFET plays its part during on-periods and switching instants. The switching loss is analyzed by l linearized modelling and the operation of the converter are investigated by simulation results.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.4
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• pp.617-624
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• 2023

Recently, miniaturization and low power consumption of electronic products and improved efficiency and power factor improvement have become a matter of great interest. In this paper, an AC-DC converter based on PWM control was designed and made. The AC-DC converter is designed with a structure in which one rectifier circuit and one output voltage control circuit are connected in series. The rectifier circuit is a diode-based single phase full-wave current circuit and the output voltage control circuit is a DC-DC conversion circuit based on PWM control. Arduino was used as the main control device for PWM control, and LCD was configured at the output stage so that the control result could be checked. The error between the output voltage displayed on the oscilloscope and LCD and the target output voltage was confirmed through repeated experiments with the test circuit, and the validity of the proposed design methodology was confirmed by showing an error rate of about 5% based on the oscilloscope measurement value.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1010-1011
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• 2015

최근 고효율 전력변환을 위해 LLC 공진형 하프브릿지 컨버터의 동기정류기에 대한 연구가 활발히 진행되고 있다. 기존 일반적인 다이오드 정류기를 사용하는 경우 출력전류에 비례하는 전력손실이 커서 대전력용으로 사용하기에는 적합하지 않다. 따라서 스위치를 이용한 동기정류기가 검토되고 있는데 동기정류기의 스위치를 구동시키기 위해서는 스위치를 구동시킬 수 있는 구동용 IC가 이용되고 있다. 동기정류기 구동 IC의 단점으로는 약 50%의 중부하 이하에서는 동작되지 않는 단점이 있어 이를 보완하기 위하여 변압기 1차측 전류를 검출하여 게이트 전압을 만들어 스위치를 구동시키는 회로를 제안하였다. 본 논문의 실험 결과 저전력 지점에서 동기정류기가 구동되었고 따라서 전력변환 효율은 기존의 다이오드 정류기에 비해 우수하며 효율개선효과가 있다는 것을 실험으로 보였다.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.5-6
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• 2011

최근 환경 문제와 에너지 자원 고갈 등의 이유로 전력 사용에 있어서 효율이 매우 중요시 되고 있다. 이와 맞물려 기존의 교류배전에 비해 직류배전이 가지는 효율적 이점이 주목받으면서 직류 배전에 대한 연구가 활발히 이루어 지고 있다. 본 연구에서는 직류배전 적용시 이용 가능한 양방향 AC/DC 전력 변환기의 경부하 효율 향상을 위해 새로운 skip-cycle mode를 개발하고 이를 디지털 제어를 이용하여 구현하였다. 풀브릿지 타입의 3.3kW 양방향 전력변환기를 이용하였다.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.138-139
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• 2010

기존의 DC/DC 전력변환기에서는 소프트 스위칭 방식과 하드 스위칭 방식을 혼용하고 있어 반도체 소자의 고속 스위칭에 의해 시스템 효율이 낮다. 이에 본 논문에서는 이러한 단점을 극복하기 위해 새로운 동기형 스위칭 방식의 Full-Bridge 전력변환기의 구조를 제안하였으며, 동기형 스위칭 방식의 ZVS 스위칭을 적용하여 턴 온/오프시 스위칭 소자에 생기는 전력 손실을 감소시키므로서 효율을 개선한다. 절연형 DC/DC 컨버터를 구성하고, PSIM을 이용한 시뮬레이션을 수행하여 제안된 DC/DC 컨버터의 효율이 우수함을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.12
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• pp.23-30
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• 2011

This paper presents a Single-Inductor Multiple-Output (SIMO) DC-DC Converter with a negative feedback selection circuit to improve a regulation property at light load and to generate independent multiple outputs. The conventional SIMO DC-DC converter with a fixed negative feedback circuit cannot regulate correctly at light load. The SIMO DC-DC converter with the proposed negative feedback selection circuit has been designed in 0.35um 2-poly 3-metal BCDMOS. This converter is dual output boost converter with the 1.5V input and 2.5V, 3.0V output. The power conversion efficiency varies from 59% at 10mA loads to 85% at 50mA loads.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.6
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• pp.16-24
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• 2009

In this paper, DC-DC buck converter with on-chip filter inductor and capacitor is presented. By operating at high switching frequency of 50MHz with stacked interleaved topology, we reduced inductor and capacitor sizes compared to previously published DC-DC buck converters. The proposed circuit is designed in a standard $0.5{\mu}m$ CMOS process, and chip area is $9mm^2$. This circuit operated at the input voltage of $3{\sim}5V$ range, the maximum load current of 250mA, and the maximum efficiency of 71%.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.5
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• pp.455-461
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• 2015

This paper deals with an experimental verification of a temperature-dependent power loss model of a DC/DC converter in severe temperature conditions. The power loss of a DC/DC converter is obtained by summing the losses by the components constituting the converter including switching elements, diodes, inductors, and capacitors. MIL-STD-810F stipulates that any electronic devices must be operable in the temperature ranging from $-50^{\circ}C$ to $70^{\circ}C$. We summarized the temperature-dependent loss models for the converter components. A SEPIC-type converter is designed and built as a target. Using a constant-temperature chamber, a test rig is set up to measure the power loss of the converter. The experimental results confirm the validity of the loss model within 4.5% error. The model can be useful to predict the efficiency of the converter at the operating temperature, and to provide guidelines in order to improve the efficiency.