• 전력전자학회논문지
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• 제23권3호
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• pp.174-181
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• 2018

This study introduces a systematic approach to selecting the internal parameters applied to the equivalent electrical-circuit model (EECM) of a lithium titanium oxide ($Li_4Ti_5O_{12}$; LTO) rechargeable cell. Based on the dynamic characteristic of the cell, a simplified EECM consisting of an open-circuit voltage (OCV), an ohmic resistance, and an RC ladder is fabricated. To select the internal parameters of a simplified EECM, experiments on discharge capacity, OCV, and discharge/charge resistances are performed using hybrid pulse power characterization and direct current internal resistance (DCIR) measurements over the full state-of-charge (SOC) range. The experimental results of the LTO rechargeable cell highlight the importance of correct selection of internal parameters that can reduce EECM errors. This study clearly provides experimental procedures, internal parameters results, and EECM guidelines for adaptive control-based SOC estimation for LTO rechargeable cells.

• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.396-400
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• 2009

In this paper, electromagnetic topology (EMT) was used to analyze the electromagnetic compatibility (EMC) of RF circuits including passive and active components. It is difficult to obtain usable results for problems relating to electromagnetic coupling in complex systems when using conventional numerical or experimental methods. Thus it is necessary to find a new methodology for analyzing EMC problems in complicated electromagnetic environments. In order to consider the nonlinear characteristics of active components, a SPICE diode model was used. A power detector circuit and the receiver circuit of a radio control (RC) car were analyzed and experimented in order to verify the validity of this method.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권6호
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• pp.569-575
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• 2013

An improved non-quasi-static gate-source impedance model including a parallel RC block for short-channel MOSFETs is developed to simulate RF MOSFET input characteristics accurately in the wide range of high frequency. The non-quasi-static model parameters are accurately determined using the physical input equivalent circuit. This improved model results in much better agreements between the measured and modelled input impedance than a simple one with a non-quasi-static resistance up to 40GHz, verifying its accuracy.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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• pp.439-442
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• 2004

Timing delays due to VLSI circuit interconnects strongly depend on neighbor line switching patterns as well as input transition time. Considering both the input transition and input switching pattern, a new analytical timing delay model is developed by using the decoupling technique of transfer multi-coupled lines into an effective single line. The analytical timing delay model can determine the timing delay of multi-coupled lines accurately as well as rapidly. It is verified by using DSM-Technology ($0.1{\mu}m$ /low-k copper-based process) that the model has excellent agreement with the results of SPICE simulation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.675-678
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• 2005

An improved BSIM3v3 RF Macro model with RC parallel substrate circuit has been developed to simulate RF characteristics of the output admittance in MOSFET accurately. This improved model shows better agreements with measured $Y_{22}-parameter$ up to 10 GHz than conventional one with a single substrate resistance, verifying the accuracy of the improved one.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권2호
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• pp.202-215
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• 2013

This paper proposes a SEPIC-input, self-driven, active clamp ZVS converter, where an auxiliary winding and a RC delay circuit are employed to drive the active clamp switch and to achieve asymmetrical duty control without any other extra circuits. Based on the fixed dead time and the resonance between capacitors and inductors, both the main switch and the auxiliary switch can rule the ZVS operation. Detailed operation modes are presented to illustrate the self-driven and ZVS principles. Furthermore, an accurate state-space model and the transfer functions of the proposed converter have been presented and analyzed in order to optimize dynamic performance. The model provides efficient prediction of converter operations. Experimental results, based on a prototype with 80V input and 15V/20A output, are discussed to verify the transient and steady performance of the proposed converter.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권4호
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• pp.471-477
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• 2014

In this paper, a modeling and co-simulation methodology is proposed to predict the radiated electromagnetic interference (EMI) from on-chip switching I/O buffers. The output waveforms of I/O buffers are simulated including the on-chip I/O buffer circuit and the RC extracted on-chip interconnect netlist, package, and printed circuit board (PCB). In order to accurately estimate the EMI, a full-wave 3D simulation is performed including the measurement environment. The simulation results are compared with near-field electromagnetic scan results and far-field measurements from an anechoic chamber, and the sources of emission peaks were analyzed. For accurate far-field EMI simulation, PCB power trace models considering IC switching current paths and external power cable models must be considered for accurate EMI prediction. With the proposed EMI simulation model and flow, the electromagnetic compatibility can be tested even before the IC is fabricated.

• 조명전기설비학회논문지
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• 제28권11호
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• pp.77-83
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• 2014

The Estimation of State of Charge(SOC) for batteries is an important aspect of a Battery Management System(BMS). A method for estimating the SOC is proposed in order to overcome the individual disadvantages of the current integral and Open Circuit Voltage(OCV) estimation methods by combining them using Extended Kalman filter(EKF). The non-linear characteristics of the Li-Ion RC battery model used in this study is also solved through EKF. The proposed method is simulated in a Matlab environment with a Li-Ion Kokam battery (3.7V, 1,500mAh). Results showed that there is an improvement in the estimation error when using the proposed model compared to the conventional current integral method.

• 전자공학회논문지
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• 제53권11호
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• pp.25-31
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• 2016

FinFET의 기생 커패시턴스와 기생저항은 회로의 고주파 성능을 결정하는 매우 중요한 요소이다. 선행 연구에서 BSIM-CMG에 구현된 FinFET의 기생 커패시턴스와 저항 모델보다 더 정확한 압축 모델을 개발하였다. 모델의 정확도를 검증하고, FinFET으로 구현 가능한 RF 회로의 성능을 정확하게 예측하기 위해 $S_{21}$ 10dB 이상 중심 주파수 60GHz 이상을 갖는 Low Noise Amplifier (LNA) 에 설계하였다. 22 nm FinFET 소자의 압축모델에 기반한 HSPICE를 사용하여 예측한 회로 성능의 정확도를 검증하기 위해 3D TCAD simulator인 Sentaurus의 mixed-mode 기능을 사용하여 LNA를 시뮬레이션 하였다. TCAD 시뮬레이션 결과를 정확도 측정의 기준으로 삼아 10GHz~100GHz 대역에서 제안한 모델과 Sentaurus의 $S_{21}$을 비교한 결과 87.5%의 정확도를 달성하였다. 이는 기존의 BSIM-CMG의 기생성분으로 예측한 정확도가 56.5%도임에 비해 31% 향상된 정확도를 보여준다. 이를 통해 FinFET의 기생 성분 모델의 정확도를 RF 영역에서 확인하였고, 정확한 기생 저항과 커패시턴스 모델이 LNA 성능을 정확하게 예측하는데 중요한 것임을 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.56-57
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• 2014

본 논문에서는 $LiCoO_2$ 원통형(cylindrical)셀을 확장칼만필터(extended Kalman filter; EKF) 추정알고리즘에 적용 시 등가회로모델 차이에 따른 SOC(State-of-charge) 추정성능의 비교 분석을 진행하였다. 첫 번째, 등가회로 모델의 성능을 좌우하는 RC-ladder의 개수에 따른 SOC 추정성능의 차이를 비교하였고, 두 번째, 모델 단순화에 따른 불가피한 모델의 에러를 줄이고자 사용되는 노이즈 모델(noise model) 및 데이터 리젝션(data rejection)의 유무에 따른 SOC 추정성능을 비교분석 하였다.