• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.7
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• pp.559-562
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• 2009

Due to the enormous progress achieved in light emitting diodes (LEDs) LEDs have been become a good solution for lightings. In LED driver for lighting applications, it is required high input voltage to drive more LEDs. Therefore, high-voltage should be changed to low-voltage to supply power for drive IC. In this paper, LED drive IC using voltage clamp bias circuit, it use a hysteretic-buck converter topology was proposed and verified through experiments.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.85-87
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• 2009

Due to the enormous progress in light emitting diodes (LEDs), LEDs have been become a good solution for lightings. In LED driver for lighting applications, it is required a high input voltage to drive more LEDs. Therefore, a high-voltage should be changed to low-voltage to supply power for drive IC. In this paper, a LED drive IC with hysteretic-buck converter topology using a voltage clamp bias circuit was proposed and verified through simulations.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.41-44
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• 2001

본 논문은 액정 Driver IC에 사용되a는 내부 기준 clock 발생 및 Voltage Converter에 boosting을 하기 위한 clock을 제공하는 Oscillator 설계 및 구현 하였다 LCD Driver IC에서 발생되는 Oscillator clock 은 고속의 clock신호는 필요로 하지 않으나 LCD display에 관련된 frame 주파수에 직접적인 영향을 주므로 중심 주파수 결정 및 duty비에 따른 주파수 제어가 매우 중요하다. 본 논문에서는 가변 duty를 적용하는 LCD system에 적용할 수 있는 가변 duty oscillator를 소개한다. Process는 0.35um, 12V공정을 사용하였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.10
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• pp.7-14
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• 2008

In this paper, we designed the HVIC(High Voltage Gate Driver IC) which has improved noise immunity characteristics and high driving capability. Operating frequency and input voltage range of the designed HVIC is up to 500kHz and 650V, respectively. Noise protection and schmitt trigger circuit is included in the high-side level shifter of designed IC which has very high dv/dt noise immunity characteristic(up to 50V/ns). And also, rower dissipation of high-side level shifter with designed short-pulse generation circuit decreased more that 40% compare with conventional circuit. In addition, designed HVIC includes protection and UVLO circuit to prevent cross-conduction of power switch and sense power supply voltage of driving section, respectively. Protection and UVLO circuit can improve the stability of the designed HVIC. Spectre and Pspice circuit simulator were used to verify the operating characteristics of the designed HVIC.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.451-469
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• 2014

The purpose of this study is to implement and develop the integrated Economic Value Added (EVA) and Time-Driven Activity-Based Costing (TDABC) model to seek both improvement of Net Operating Profit Less Adjusted Tax (NOPLAT) and reduction of Capital Charge (CC). Net Operating Profit Less Adjusted Tax (NOPLAT) can be maximized by reducing the indirect cost of an unused resource capacity increased by Cost Capacity Ratio (CCR) of TDABC. On the other hand, Capital Charge (CC) can be minimized by improving the efficiency of Invested Capital (IC) considered by Weighted Average Cost of Capital (WACC) of EVA. In addition, the integrated system of TDABC using Balance Scorecard (BSC) and EVA is developed by linking between the lagging indicators and the three leading indicators. The three leading indicators include customer, internal process and growth and learning perspectives whereas the lagging indicator includes NOPLAT and CC in terms of financial perspective. When the Critical Success Factor (CSF) of BSC is cascading as a cause and an effect relationship, time driver of TDABC and capital driver of EVA can be used efficiently as Key Performance Indicator (KPI) of BSC. For a better understanding of the proposed EVA/TDABC model and BSC/EVA/TDABC model, numerical examples are derived from this paper. From the proposed model, the time driver of TDABC and the capital driver of EVA are known to lessen indirect cost from comprehensive income statement when increasing the efficiency of operating IC from the statement of financial position with unified KPI cascading of aligned BSC CSFs.

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.6
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• pp.504-513
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• 2009

This paper proposes the new type LED driver modularization for illumination LED driver. The proposed LED driver circuit insulates a hot GND of AC input power and a cold GND of LED driver part by using a fly-back converter. In order to control easily the current of the LED, the fly-back converter is operated in the discontinuous mode with excellent dynamic characteristics, and the characteristics of the LED are verified after the closed loop control is performed using a KIA2431. The LED driver module allows the wide AC power input ranges and realizes the burst dimming function which directly regulates a PWM control IC. This paper describes the operation principle of the LED driver module and it is proved the usefulness through the real model with experimentation. Besides, this paper proposes the multi-channel LED driver which the miniaturized and modularized LED driver module are connected by parallel, and verified its propriety by experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5832-5837
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• 2011

In this paper, we designed a thermal shutdown block for LED applications using a 1 ${\mu}m$ CMOS process. The proposed thermal shutdown protection circuit has been designed with a shut-off temperature of $120^{\circ}C$ and a restart temperature of $90^{\circ}C$ which are suitable conditions for LED driver IC. Also, we got SPICE simulation results of the circuit about process variation of the semiconductor fabrication. From simulation data, process variation rate of the proposed circuit are within 7 % which are good results compared with conventional BJT current mirror type circuit. Finally, we confirmed that the thermal shutdown circuit has good thermal protection function within a LED driver IC.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.129-134
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• 2021

A power tool is a tool used to manufacture and process various structures using a motor that is a power source. Using a motor that uses electricity as a power source, a reduction device, power transmission and conversion device functions are built-in to make the tool rotate, reciprocate, and vibrate. It is a work tool designed to assist the user's movement skills. In the case of Korea, the power tool industry has a short history and is lagging behind advanced countries such as Germany, the United States, and Japan in terms of technology level, market share, and recognition. In addition, electric drivers used in Korea are foreign products from the US and European countries, and the domestic market also prefers 100% foreign companies, and multinational companies are investing a lot in the domestic market. Therefore, technological development must follow in order to develop domestic technology and secure a consistently high market share. The purpose of this thesis is to design a motor driver with high output performance of motor performance, miniaturization, and high speed in accordance with the basic performance requirements of power tools, and finally research developments that can be applied to industrial and medical applications.

• Journal of Power Electronics
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• v.12 no.6
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• pp.886-894
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• 2012

This paper presents a secondary-side, dual-mode feedback LLC resonant controller IC with dynamic PWM dimming for LED backlight units. In order to reduce the cost, master and slave outputs can be generated simultaneously with a single LLC resonant core based on dual-mode feedback topologies. Pulse Frequency Modulation (PFM) and Pulse Width Modulation (PWM) schemes are used for the master stage and slave stage, respectively. In order to guarantee the correct dual feedback operation, Phased-Locked Loop (PLL)-based automatic duty control circuit is proposed in this paper. The chip is fabricated using $0.35{\mu}m$ Bipolar-CMOS-DMOS (BCD) technology, and the die size is $2.5mm{\times}2.5mm$. The frequency of the gate driver (GDA/GDB) in the clock generator ranges from 50 to 425 kHz. The current consumption of the LLC resonant controller IC is 40 mA for a 100 kHz operation frequency using a 15 V supply. The duty ratio of the slave stage can be controlled from 40% to 60% independent of the frequency of the master stage.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.36-43
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• 2013

In this study, the high current behaviors and double snapback mechanism of gate grounded_extended drain n-type MOSFET(GG_EDNMOS) device were analyzed in order to realize the robust electrostatic discharge(ESD) protection performances of high voltage operating display driver IC(DDIC) chips. Both the transmission line pulse(TLP) data and the thermal incorporated 2-dimensional simulation analysis as a function of ion implant conditions demonstrate a characteristic double snapback phenomenon after triggering of bipolar junction transistor(BJT) operation. Also, the background carrier density is proven to be a critical factor to affect the high current behavior of the GG_EDNMOS devices.