• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.557-560
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• 2004

In this study, we design the one-chip PWM IC for SMPS (Switching Mode Power Supply) application. We determine the IC spec. and simulated each block of PWM IC (Reference, Error amp., Comparator, Oscillator) with Smart Spice (SILVACO Circuit Simulation Tool). Reference circuits generate constant voltage(5V) in the various of power supply and temperature condition. Error amp. is designed with large DC gain (${\simeq}65dB$), unity frequency (${\simeq}190kHz$) and large PM($75^{\circ}$).Saw tooth generators operate with 20K oscillation frequency (external resistor, capacitor).

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.3
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• pp.341-346
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• 2017

In this paper, we present a 60 GHz on-off keying (OOK) modulator in a 90 nm CMOS. The modulator employs a current-reuse technique and a switching modulation for low DC power dissipation, high on/off isolation, and high data rate. The measured gain of the modulator, on/off isolation, and output 1-dB compression point is 9.1 dB, 24.3 dB, and 5.1 dBm, respectively, at 60 GHz. The modulator consumes power consumption of 18 mW, and is capable of handling data rates of 8 Gb/s at bit error rate of less than $10^{-6}$ for $231^{-1}$ PRBS over a distance of 10-cm with an OOK receiver module.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.211-212
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• 2016

본 논문에서는 비절연 고승압 소프트 스위칭 양방향 DC-DC 컨버터의 PWM Plus Phase Shift(PPS) 제어기법을 제안한다. 제안하는 컨버터는 기존의 하프브리지 양방향 컨버터의 2배의 승 강압비를 가지며 CCM에서 모든 스위치가 소프트스위칭을 성취한다. 또한, PPS 제어기법을 적용하여 스위치의 전압/전류정격을 최소화할 뿐 아니라 매끄러운 모드전환이 가능하다. 제안하는 양방향 컨버터의 3kW 시작품은 5.2배의 승 강압동작에서 최고효율 97.2%, 97.5%를 달성하였다.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.1-2
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• 2011

본 논문에서는 D=0.5에서 2배의 승 강압비를 갖는 하이브리드 자동차 HDC용 비절연 양방향 DC-DC 컨버터를 제안한다. 제안한 컨버터는 CCM에서도 소프트스위칭이 가능하며 스위치 전압정격이 1/2로 되어 소자의 선정에 유리하다. 또한 수동소자의 부피도 기존 양방향 컨버터 보다 작아 고효율 및 고전력 밀도를 달성할 수 있다. 제안하는 양방향 컨버터의 최적의 스위칭 기법을 제안하였고 10kW급 축소시작품의 실험을 통해 본 논문의 타당성을 검증하였다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.5
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• pp.230-237
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• 2003

Current mode control has been used for DC to DC converters for over twenty years. There are many different control schemes which use the inductor current signal in one way or another to control the DC to DC converter. In this paper, the state space averaging technique is applied for the analysis of flyback type current mode control circuit. We made real converter for the guarantee of stable output characteristic and proper design of feedback circuit. The validity of proposed method is verified from test result. The improvement of stability is confirmed by sinusoidal signal injection method with isolated transformer. It is known that phase margin is sufficient and gain crossover frequency fc is early 1/5 of switching frequency, fs, from the experimental result with frequency response analyzer.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.1
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• pp.47-57
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• 1991

A new control algorithm so called equal excursion sliding mode (EESM) control method is proposed to control the position of DC servo motor. This method introduces the concept of phase velocity vector that Filippov presented, and simplifies the problem of control gain selection in a conventional VSC strategy. And, by making state trajectories have equal excursions on both sides of switching hyperplane we minimized the probability of sliding mode's being collapsed, and approximated to the ideal sliding moed. Also, we proved the validity of this method by comparing the application results of this method to DC servo motor with those of conventional VSC strategy.

• Proceedings of the KIPE Conference
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• 1996.06a
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• pp.63-66
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• 1996

An micro model for the power insulated Gate Bipolar Transistor(IGBT) is developed. The model consistently described the IGBT steady-state current-voltage characteristics and switching transient current and voltage waveform for all loading conditions. The model is based on the equivalent circuit of a MOSFET with supplies the base current to a low-gain, high-level injection, bipolar transistor with its base virtual contact at the collector and of the base. Model results are compared with measured turn-on and turn-off waveform for different drive, load, and feedback circuits.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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• pp.81-86
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• 2007

Electric utility companies have the responsibility of providing good electricity for their customers. They have introduced the DAS(Distribution Automation System) to automate the power distribution networks. DAS engineers require state-of-the-art applications, such as a way to actively manage the distribution system and gain economic benefits from a flexible DAS architectural design. The existing DAS is not capable of handling these needs. It requires operator intervention whenever feeder overloading is detected while operator error could cause the feeder overload area to be extended. It also utilizes a closed architecture and it is therefore difficult to meet the system migration and future enhancement requirements. This paper represents a web based, platform-independent, flexible DAS architectural design and active database application. Recent advanced Internet technologies are fully utilized in this new DAS architecture allowing it to meet the system migration and future enhancement requirements. By using an active database, the DAS can minimize the feeder overloading area in the distribution system without operator intervention, thereby minimizing mistakes due to operator error.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1115-1119
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• 2007

Five control methods (Speed Control, PID Gain Scheduling, Loop Time Control, Simple PID, Switching Control) have been applied to the control of an Inline Co-axial valve by the simulation of AMESim. The simulation results have shown that the speed control method is the most stable and the fastest way to reach to the set point in the simulation of the flow control. Moreover, It has been found that the five control methods have the almost same characteristics in the power consumption, the counter electromotive force, and the motor angular velocity. According to the analysis results, the fast and stable control characteristics of the speed control method is the most suitable for the flow control using a inline co-axial valve with a DC(BLCD) motor.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.854-858
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• 1987

This paper considers impulsive noise which produce burst error in high speed(approx.160Kbps) data transmission like ISDN(Integrated Servise Digital Network) using PSTN(Public Switching Telephone Network). To begin with, we obtains the transfer function of subscriber line to calculate the variation of bandwidth when the gain of receiver is fixed and channel capacity of non-gaussian channel in upper-and lower bound, and evaluates the transmission capability. In this paper compares channel capacity bounds which obtains when probability density function of impulsive noise is Laplacian distribution function with impulsive noise generated by waveform synthesier.