• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.186-189
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• 2006

The flexible organic thin film transistor (OTFT) array to use as a switching device for an organic light emitting diode (OLED) was designed and fabricated in the microcontact printing and room temperature process. The gate, source, and drain electrode patterns of OTFT were fabricated by microcontact printing process. The OTFT array with dielectric layer and organic active semiconductor layer formed at room temperature or at a temperature lower than $40^{\circ}C$. The microcontact printing process using SAM and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even submicron size, and reduced the fabrication process by 10 steps compared with photolithography. Since the process was done in room temperature, there was no pattern shrinkage, transformation, and bending problem appeared. Also, it was possible to improve electric field mobility, to decrease contact resistance, to increase close packing of molecules by SAM, and to reduce threshold voltage by using a big dielectric.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.82-85
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• 2000

We introduce pulsed $CO_2$ laser power supply excited by half-wave rectified 60Hz AC discharge some advantage of cost and size compared to a typical pulsed power supply. AC frequency is adjusted from 10Hz to 60Hz to control laser output. In this laser, a low voltage open loop control for high voltage AC discharge circuits is employed to avoid the HV sampling or switching. The control is achieved by using a ZCS circuit and a PIC one-chip microprocessor that control the gate signal of SCR precisely. The pulse repetition rate is limited by 60Hz due to a high leakage inductance. The maximum laser output was obtained about 20W at the condition of total pressure, 18Torr and pulse repetition rate,60Hz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.88-96
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• 2016

In this paper, the GaN FET based phase-shift full-bridge dc-dc converter design is implemented. Switch characteristics of GaN FET were analyzed in detail by comparing state-of-the-art Si MOSFET. Owing to the low conduction resistance and parasitic capacitance, it is expected to GaN FET based power conversion system has improved performance. However, GaN FET is vulnerable to electric interference due to the relatively low threshold voltage and fast switching transient. Therefore, it is necessary to consider PCB layout to design GaN FET based power system because PCB layout is the main reason of stray inductance. To reduce the electric noise, gate voltage of GaN FET is analyzed according to operation mode of phase-shift full-bridge dc-dc converter. Two 600W phase-shifted full-bridge dc-dc converter are designed based on the result to evaluate effects of stray inductance.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.35C no.12
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• pp.31-39
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• 1998

This paper presents the design and implementation of a new multimedia fixed-point DSP (MDSP) core for portable multimedia applications. The MDSP instruction set is designed through the analysis of multimedia algorithms and DSP instruction sets. The MDSP architecture employs parallel processing techniques, such as SIMD and vector processing as well as DSP techniques. The instruction set can handle various data formats and MDSP can perform two MAC operations in parallel. The switching network and packing network can increase the performance by overlapping data rearrangement cycles with computation cycles. We have designed Verilog HDL models and the 0.6 $\mu\textrm{m}$ Samsung KG75000 SOG library is used. The total gate count is 68,831 and the clock frequency is 30 MHz.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.6
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• pp.622-634
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• 2013

The circuit level implementation of nanoscale Insulated Shallow Extension Silicon On Nothing (ISE-SON) MOSFET has been investigated and compared with the other conventional devices i.e. Insulated Shallow Extension (ISE) and Silicon On Nothing (SON) using the ATLAS 3D device simulator. It can be observed that ISE-SON based inverter shows better performance in terms of Voltage Transfer Characteristics, noise margin, switching current, inverter gain and propagation delay. The reliability issues of the various devices in terms of supply voltage, temperature and channel length variation has also been studied in the present work. Logic circuits (such as NAND and NOR gate) and ring oscillator are also implemented using different architectures to illustrate the capabilities of ISE-SON architecture for high speed logic circuits as compared to other devices. Results also illustrates that ISE-SON is much more temperature resistant than SON and ISE MOSFET. Hence, ISE-SON enables more aggressive device scaling for low-voltage applications.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.8
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• pp.486-489
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• 2015

Power semiconductor device has a very long history among semiconductor, since the invention of low-pressure bipolar transistor 1947, and so far from small capacity to withstand voltage-current, high-speed and high-frequency characteristics have been developed with high function. In this study, the PWM IC Switch to the main parts used in IGBT (insulated gate bipolar transistor) for the low power loss and high drive capability of the simulator to Synopsys' T-CAD used by the 1,700 V NPT Planar IGBT, 1,700 V FS was a study of the Planar IGBT, the results confirmed that IGBT 1,700 V FS Planar is making about 11 percent less than the first designed NPT Planar IGBT.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.287-288
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• 2010

The Induction Heating equipment is widely used for steel plate heating in the surface treatment process of steel industries. In the case of thin steel plate, for high efficiency We need the high frequency induction heating equipment more than 100kHz. But it is difficult to realize the high frequency and high power at the same time. That's why most high frequency equipment more than 100kHz has been imported from advanced Manufacturer. This paper will describe the development of 100kHz/5MVA inverter module for 100kHz/20MVA induction heating. We used the LCL resonance topology and ZVS/ZCS switching technology. And we also developed the low loss gate drive board and plate busbar inverter stack. We proved the performance by various experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.595-596
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• 2006

The flexible organic thin film transistor (OTFT) array to use as a switching device for an organic light emitting diode (OLED) was designed and fabricated in the microcontact printing and low-temperature processes. The gate, source, and drain electrode patterns of OTFT were fabricated by microcontact printing which is high-resolution lithography technology using polydimethylsiloxane(PDMS) stamp. The OTFT array with dielectric layer and organic active semiconductor layers formed at room temperature or at a temperature tower than $40^{\circ}C$. The microcontact printing process using SAM(self-assembled monolayer) and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even nano size, and reduced the procedure by 10 steps compared with photolithography. Since the process was done in low temperature, there was no pattern transformation and bending problem appeared. It was possible to increase close packing of molecules by SAM, to improve electric field mobility, to decrease contact resistance, and to reduce threshold voltage by using a big dielecric.

• Journal of Magnetics
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• v.8 no.1
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• pp.24-31
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• 2003

The discoveries of antiferromagnetic coupling in Fe/Cr multilayers by Grunberg, the Giant Magneto Resistance by Fert and Grunberg and a large tunneling magnetoresistance at room temperature by Moodera have triggered enormous research on magnetic thin films and magnetoelectronic devices. Large opportunities are especially opened by the spin dependent tunneling resistance, where a strong dependence of the tunneling current on an external magnetic field can be found. We will briefly address important basic properties of these junctions like thermal, magnetic and dielectric stability and discuss scaling issues down to junction sizes below 0.01 $\mu\textrm{m}$$^2$with respect to single domain behavior, switching properties and edge coupling effects. The second part will give an overview on applications beyond the use of the tunneling elements as storage cells in MRAMs. This concerns mainly field programmable logic circuits, where we demonstrate the clocked operation of a programmed AND gate. The second 'unconventional' feature is the use as sensing elements in DNA or protein biochips, where molecules marked magnetically with commercial beads can be detected via the dipole stray field in a highly sensitive and relatively simple way.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.612-615
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• 2013

Hub BLDC(Brushless Direct Current) motor, called wheel-in motor is a outer rotor type high efficient direct driving motor which have a multi-pole permanent magnet type rotor as a driving wheel. This study shows a hub BLDC motor speed controller design methode using PIC micro controller to drive 2 wheels or 3 wheels driving body having hub motor driving shaft. The motor driver unit consists of six discrete MOSFET switching devices and the gate driving module is directly designed for high economy.