• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.215-218
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• 2001

In conventional three-phase rectifiers, it was necessary to use a transformer to obtain low output voltage. In this paper, we propose a new three-phase rectifiers circuit that achieves low voltage by using a very simple circuit configuration that does not have a transformer and does not need any complex control. We also describe the operation principle of the proposed circuit, and derive a theoretical formula for its current waveform. On the basis of this formula it also explores the theoretical input/output current characteristics, theoretical current amplification factor, and theoretical output voltage characteristics of these theoretical values with experimentally obtained input/output current characteristics, current amplification factor, and output voltage characteristics, allowed us to confirm the soundness of our theoretical analyses.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.703-706
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• 1998

This paper presents an efficient substrate-bias generator(SBG)for low-power, high-density DRAM's The proposed SBG can supply stable voltage with switching the supply voltage of driving circuit, and it can substitude the small capacitance for the large capacitance. The charge pumping circuit of the SBG suffere no VT loss and is to be applicable to low-voltage DRAM's. Also it can reduce the power consumption to make VBB because of it's high pumping efficiency. Using biasing voltage with positive temperature coefficient, VBB level detecting circuit can detect constant value of VBB against temperature variation. VBB level during VBB maintaining period varies 0.19% and the power dissipation during this period is 0.16mw. Charge pumping circuit can make VBB level up to -1.47V using VCC-1.5V, and do charge pumping operation one and half faster than the conventional ones. The temperature dependency of the VBB level detecting circuit is 0.34%. Therefore the proposed SBG is expected to supply a stable VBB with less power consumption when it is used in low power DRAM's.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.221-223
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• 2003

This paper presents a new hybrid control method of asymmetrical/symmetrical half-bridge converter (AHBC/SHBC) with low voltage stress of the diodes. The proposed new control scheme is executed by using feedback of the input voltage and then can decide operation of the converter is divided into two ranges, which are asymmetrical control and symmetrical control, So the proposed control scheme has many advantages such as a low rated voltage of the secondary diodes, and low conduction loss according to the low voltage drop. The proposed control scheme is verified by simulated results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1877-1880
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• 2005

This paper proposed the new current feed-back amplifier for low supply voltage application. The input stage was designed to be a class-AB circuit and achieve the low supply-voltage operation down to $2V_{TH}+2V_{DS(SAT)}$. With the self-adjust bias current, the high performance can be adopted with high stability. The circuit was successfully proven by the simulation with MOSIS 0.5 ${\mu}$m MOS technology.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.979-982
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• 2003

Due to the differential transmission technique and low voltage swing, LVDS has been widely used for high speed transmission with low power consumption. This paper presents the design and implementation of interface circuits for 1.5Gb/s operation in 0.35um CMOS technology. The interface circuit ate fully compatible with the low-voltage differential signaling(LVDS) standard. The LVDS proposed in this paper utilizes a sense amplifiers instead of the conventional differential pre-amplifier, which provides a 1.5Gb/s transmission speed with further reduced driver output voltage. Furthermore, the reduced driver output voltage results in reducing the power consumption.

• 조명전기설비학회논문지
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• 제23권12호
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• pp.127-135
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• 2009

본 연구에서는 2개의 인덕터를 이용한 인터리브 AC/DC 승압형 컨버터의 듀티 사이클이 0.5 이상일 때 배압 회로 특징을 나타내었다. 일반적으로 AC/DC 승압형 컨버터는 낮은 입력전압(입력 AC 110[V])이 높은 입력전압(입력 AC 220[V])에 비하여 낮은 효율을 갖는다. 제안된 인터리브 AC/DC 승압형 컨버터는 낮은 입력전압에서 배압 회로로 동작함으로 인하여 낮은 입력전압을 사용하는 기존의 컨버터와 비교하여 높은 역률과 향상된 효율을 갖는다. 본 연구에서는 배압 회로 동작하는 하는 인터리브 AC/DC 승압형 컨버터를 제안하고, 모드별 해석과 특성을 논의하였으며, 300[W]급 시작품을 제작하여 그 타당성을 검증하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.61-64
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• 2000

This paper describes a RF Down-Conversion Mixer for mobile communication systems. This circuit achieves low voltage operation and low power consumption by reducing stacked devices of conventional gilbert cell mixer. In order to reduce stacked devices, we use source-follower structure. The proposed RF Down-Conversion mixer operates up to 1.85GHz at 1.5V power supply with 0.25um CMOS technology and consumes 2.2mA.

• 한국전자통신학회논문지
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• 제8권10호
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• pp.1477-1483
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• 2013

연속시간 전류모드 기저대역 채널선택 필터 설계를 위하여 전류이득과 단위이득 주파수를 개선시킨 저전압 선형 캐스코드 전류모드 적분기를 제안하였다. 제안된 전류모드 적분기는 CMOS 상보형 회로로 구성된 완전 차동 형태의 입 출력단으로 구성하였으며, 여기에 캐스코드 트랜지스터를 추가시킴으로써 바이어스 단을 구성하여 선형영역에서 동작시켜 저전압 구조에 적합하도록 설계하였다. 이 때 바이어스 전압을 선택적으로 제어하여 주파수 대역이 가변될 수 있도록 설계하였다. 시뮬레이션 결과를 통해 설계한 선형 캐스코드 전류모드 적분기가 저전압 동작, 전류 이득 및 단위이득 주파수 등 모두 만족할 만한 특성을 가지고 있음을 확인하였다.

• Journal of Power Electronics
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• 제8권1호
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• pp.51-59
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• 2008

This paper addresses several issues concerning the analysis, design, modeling, simulation and development of single-phase, single-switch, power factor corrected AC-DC high frequency switching converter topologies with transformer isolation. A detailed analysis and design is presented for single-switch topologies, namely forward buck, flyback, Cuk, Sepic and Zeta buck-boost converters, with high frequency isolation for discontinuous conduction modes (DCM) of operation. With an awareness of modem design trends towards improved performance, these switching converters are designed for low power rating and low output voltage, typically 20.25W with 13.5V in DCM operation. Laboratory prototypes of the proposed single-switch converters in DCM operation are developed and test results are presented to validate the proposed design and developed model of the system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.370-376
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• 1993

In this paper, we present the voltage source algorithm for high speed and low torque ripple operation of a switched reluctance motor (SRM). The SRM has simpler structure than the traditional dc or ac motor. It has a high starting torque and can be operated in the wide range of speed. So it can be applied to various areas. But the SRM has some difficulties in driving circuit and controller due to the large inductance variations. In this study, in order to produce the low torque ripple and the high speed operation, a voltage source algorithm is proposed. We showed the good performance of the proposed controller through simulation and experiment.