• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.3
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• pp.485-490
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• 2012

In this paper, driver circuit of LED lights for ships is designed and implemented to replace conventional lights with filament which have short life time due to vibration of ships. The driver of LED module is switching circuit without transformer to reduce volume and cost. As switch circuit controls input 220 VAC with PWM, LED module is reliably driven. Power factor is improved by using valley-fill PFC compensation circuit which is handled to pulse current of switching circuit. Serial-parallel LED circuit is applied to reduce change period of lights of long-term navigation ships. Array of serial-parallel can operate even if some of LEDs is damaged. It is suitable for ships that power consumption and power factor of lights including developed drive circuit have 39Watt and 0.925 respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1513-1517
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• 2012

As demands for green industry increase, this paper proposes a power control technique that can substitute pre -existing CCFL(Cold Cathode Fluorescent Lamp) and optimize power consumption of LED BLU. This technique is designing LED driver circuit that make a DC-DC output voltage(VLED) to have a linear control function for a supply voltage of LED string. The proposed LED driver have an advantage that can increase or decrease a DC-DC output voltage compared with conventional LED driver. The designed LED driver circuit was designed using 0.35um CMOS technology. And its operation was verified through simulation.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1355-1357
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• 2005

This paper discusses Gate-driver circuit for improved switching characteristics. This resonant gate-driver recycles the energy stored in the gate capacitance to reduce the turn-off switching loss associated with a conventional gate-driver. Reducing the loss reduces the power consumption and hence the subsequent power dissipation in the resonant gate-driver. The design considerations of implementing a practical MOSFET gate-driver using this topology are discussed.

• ETRI Journal
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• v.31 no.3
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• pp.247-253
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• 2009

We propose a Ku-band driver and high-power amplifier monolithic microwave integrated circuits (MMICs) employing a compensating gate bias circuit using a commercial 0.5 ${\mu}m$ GaAs pHEMT technology. The integrated gate bias circuit provides compensation for the threshold voltage and temperature variations as well as independence of the supply voltage variations. A fabricated two-stage Ku-band driver amplifier MMIC exhibits a typical output power of 30.5 dBm and power-added efficiency (PAE) of 37% over a 13.5 GHz to 15.0 GHz frequency band, while a fabricated three-stage Ku-band high-power amplifier MMIC exhibits a maximum saturated output power of 39.25 dBm (8.4 W) and PAE of 22.7% at 14.5 GHz.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.169-172
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• 2008

This paper is a report of designing for high efficient LED lights driver. The main purpose of driver designing is meet the requirement the high efficient energy regulation for light of Korea. To meet the regulation the high efficient, the circuit adapted wide range resonant power supply and current regulate circuit to adjust LED current. This product archived excellent performance as well as reliable operation.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.153-154
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• 2017

In this paper, a short-circuit protection function of a gate driver for SiC FET is investigated, which monitors voltage between drain and source of a FET under turn-on condition and turns off the FET if the voltage exceeds a predefined value.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.8
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• pp.1644-1650
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• 2009

An improved guarding circuit is applied to a transconductance driven-right-leg circuit to decrease common-mode current at measurement electrodes due to power-line interference. After showing conventional guarding circuit is instable due to gain-peaking when used with a transconductance DRL circuit, the effect of the proposed guarding circuit modified to suppress the gain-peaking by inserting a series resistor between shields and a shield driver was analyzed. It is shown that, besides stability, the proposed guarding circuit provides two other advantages: 1) The gain of the shield driver can be set to be unit nominally. 2) The loop gain of the transconductance DRL loop can be increased due to pole-zero canceling. The proposed circuit was implemented and the advantages were confirmed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.319-324
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• 2012

This paper introduces a 2-dimensional touch screen panel driver based on an improved capacitive sensing circuit. The improved capacitive sensing circuit based on charge pump can eliminate the remaining charges of the intermediate nodes, which may cause output voltage drift. The touch screen panel driver with mixed-mode circuits was built and simulated using Cadence Spectre. Verilog-A models the digital circuits effectively and enables them to interface with analog circuits easily. From the simulation results, we can verify the reliable operations of the simple structured touch screen panel driver based on the improved capacitive sensing circuit offering no voltage drift.

• 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.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.15-20
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• 2007

This paper presents the new design method for the gate driver circuit of the floating MOSFET by using the pulse transformer. Each parameters of the proposed circuit are delivered by the numerical calculation method. By considering inner characteristics of MOSFET, the gate driver makes to increase the efficiency of the power conversion and decrease operating heat. Computer simulations and to experimental results for a Buck Converter are presented in order to validate the proposed method.