• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.41-42
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• 2009

This paper presents a motor drive IC for automotive applications. The drive IC is dedicated to control and drive external MOSFETs which directly drive 3-phase motor with a high current. In case of driving high-side power switches, the bootstrap topology is widely used. However, it requires three bootstrap diode and three capacitor respectively. And it needs a minimum charging time to maintain high-side voltage. The motor drive IC uses a charge-pump circuit for all three high-side voltage with various protection schemes for automotive applications.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.205-207
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• 2006

In this paper, we present a design procedure of high linearity LNA using CMOS technology. To enhance the low linearity of the inherent CMOS transistor, we adopt the modified derivate superposition with adding external capacitor. The simulation of the designed LNA shows $IIP_3$ of +12-dBm, power gain of 13.8-dB, noise figure of 1.75-dB over the 900 MHz UHF RFID frequencies. The circuit draws the current of 4.2 mA from 1.8-V supply voltage.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.39-42
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• 2006

a current stress reduction technique for a boost integrated half-bridge (BIHB) DC/DC converter with voltage doubler type rectifier is proposed for digital car audio amplifier application. In the proposed circuit, two external capacitors are added parallel to the rectifier diodes in the secondary side of the transformer to shape the primary and the secondary current like rectangular waveforms in every switching instance. The experimental results of a 200W industrial sample show that the peak primary current decreases about by 10A. Thus, the proposed technique shows improved high efficiency.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.59-61
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• 2006

A circuit model simulating the electrical characteristics of EEFL(External Electrode Fluorescent Lamp) is proposed. The model is based on linear approximation that represents the equivalent resistance and capacitance as a function of power. Simulation waveforms and experimental results are presented to verify feasibility of the equivalent model.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.3
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• pp.100-108
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• 2002

A simple sustain driver employing an energy recovery function is proposed as a highly efficient driver of a plasma display panel. The proposed driver uses dual resonance in the sustaining mode operation: a main resonance between an inductor and an external capacitor to produce alternative pulses and a sub-resonance between an inductor and a panel to recover the energy consumption by the capacitive displacement current of the PDP. The operational principle and design procedure of the proposed circuit are presented with theoretical analysis. The operation of the proposed sustain driver is verified through simulation and experiments based on a 7.5-inch-diagonal panel with a 200 KHz operating frequency.

• Journal of Sensor Science and Technology
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• v.25 no.5
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• pp.337-343
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• 2016

In this paper, we newly introduce a wireless identification system using a solar cell and RF transceivers. The reader sends interrogating signal to a transponder using LED visible light, and the transponder responds to the reader using RF signal. The transponder consists of a solar cell, an amplifier, a microprocessor, and an RF transmitter. The solar cell receives the visible light from the reader and generates current to supply electric power to the other devices in the transponder. At the same time, the solar cell detects interrogating signal in the reader light. The microprocessor senses the interrogating signal and generates a responding signal. The RF transmitter radiates the responding signal to the reader. The transponder is a passive circuit because it operates without external power. In experiments, the maximum read distance between a reader and a transponder was about 1.6 meter.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.66-73
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• 1999

In this paper, the design of one-chip FED system integrated with driving circuits in reported on the basis of MOSFET controlled FEA (MCFEA). To integrate a MOSFET with a FEA efficiently, a new fabrication process is proposed. It is confirmed that the MOSFET with threshold voltage of about 2volts controls the FEA emission current up to 20 ${\mu}$A by applying driving voltage of 15 volts, which is enough current level to utilize the MCFEA as a pixel for FED. The drain breakdown voltage of the MOSFET is measured to be 70 volts, which is also high enough for 60 volt operation of FED. The circuits for row and column driver are designed stressing on saving area, reducing malfunction probability and consuming low power to maximize the merit of on-chip driving circuits. Dynamic logic concept and bootstrap capacitors are used to meet these requirements. By integrating the driving circuit with FEA, the number of external I/O lines can be less than 20, irrespectively of the number of pixels.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.85-89
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• 1999

FDE panel was successfully fabricated through the integration of a 0.7" diagonal Si-based Mo-tip FEA with 25${\times}$25 pixels, Y2O3:Eu or ZnO:Zn phosphor screen, and vacuum sealing through an exhausting glass tube, including a getter. The panel system was driven by an external driver circuit having pulse width modulation(PWM) driving scheme. Before character imaging, it was stabilized through tip aging by slowly increasing a pulse-mode emission current and phosphor aging by a coulombic charging process. After aging, luminescent characteristics such as emission uniformity, charging and arcing phenomena were shown to be improved significantly.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.1089-1094
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• 2003

A main vibration source in HDD is arisen from high rotating disk/spindle, and vibration suppression of the disk-spindle system becomes a critical issue and a major concern for high performance of the drive. In this paper, we study the feasibility of suppressing unwanted vibration of disk-spindle system of the HDD by external shock and excitation utilizing piezoelectric shunt damping methodology. By considering dynamic characteristics of the disk-spindle system through modal analysis, a target vibration mode is determined and then the piezoelectric material is carefully integrated to the modified drive. In order to maximize improvement of vibration characteristics of the proposed system, shunt circuit is optimally designed via tuning processes. Finally, the vibration characteristics of the high rotating disk-spindle system of the proposed drive is experimentally evaluated in frequency domain.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.153-156
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• 2006

The vibration isolation system is a system that attenuates the vibration transmitted from surroundings by using external energy supply like electricity and feedback and/or feedforward functions. Such a system needs stiff structure to make precise positioning without ripple within a certain bandwidth. So, a horizontal and rotary arrangement of the actuation module is suggested by using lever linkage. Modeling and kinematic formulation are completed and system identification is accomplished to tune the design variables accurately. The vibration isolation control is performed by mu-synthesis with the uncertainties in design variables. Low frequency signal enhancement circuit and saturation proof integration algorithm are devised to use seismic sensors for displacement control. This overall system shows good disturbance rejection performance.