• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.1-6
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• 2012

Using a current-mode multiple reset, a current-to-voltage(I-V) converter with a wide dynamic range was produced. The converter consists of a trans-impedance amplifier(TIA), an analog-to-digital converter(ADC), and an N-bit counter. The digital output of the I-V converter is composed of higher N bits and lower bits, obtained from the N-bit counter and the ADC, respectively. For an input current that has departed from the linear region of the TIA, the counter increases its digital output, this determines a reset current which is subtracted from the input current of the I-V converter. This current-mode reset is repeated until the input current of the TIA lies in the linear region. This I-V converter is realized using 0.35 ${\mu}m$ LSI technology. It is shown that the proposed I-V converter can increase the maximum input current by a factor of $2^N$ and widen the dynamic range by $6^N$. Additionally, the I-V converter is successfully applied to a photometric sensor.

• Journal of Sensor Science and Technology
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• v.3 no.3
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• pp.22-27
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• 1994

Design of potentiostat and I-V converter for micro pO2 sensor is described. Also, The operation of the designed circuit, in connection with the eqivalent model of micro pO2 sensor, is simulated. The potentiostat showed low output resistance of $l.1k{\Omega}$ and input voltage range of $-3{\sim}2.5V$. And the I-V converter showed low input resistance of $30{\Omega}$ and good linearity between input and output.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.569-575
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• 2020

Recently, research on renewable energy technologies has come into the spotlight due to rising concerns over the depletion of fossil fuels and greenhouse gas emissions. Demand for portable electronic and wearable devices is increasing, and electronic devices are becoming smaller. Energy harvesting is a technology for overcoming limitations such as battery size and usage time. In this paper, the V-I characteristic curve and internal resistance of thermal electric devices were analyzed, and MPPT control methods were compared. The Perturbation and Observation (P&O) control method is economically inefficient because two sensors are required to measure the voltage and current of a Thermoelectric Generator(TEG). Therefore, this paper proposes a new MPPT control method that tracks MPP using only one sensor for the regulation of the output voltage. The proposed MPPT control method uses the relationship between the output voltage of the load and the duty ratio. Control is done by periodically sampling the output voltage of the DC-DC converter to increase or decrease the duty ratio to find the optimal duty ratio and maintain the MPP. A DC-DC converter was designed using a cascaded boost-buck converter, which has a two-switch topology. The proposed MPPT control method was verified by simulations using PSIM, and the results show that a voltage, current, and power of V=4.2 V, I=2.5 A, and P=10.5 W were obtained at the MPP from the V-I characteristic curve of the TEG.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.3 s.357
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• pp.52-58
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• 2007

This paper describes the PLL of TCON(Timing Controller) chip for FPD(Flat Panel Display). The recent TCON requires wide range frequency operation of $8\sim135MHz$ in PLL. In order to be satisfied this requirement the new V-I converter.circuit. The V-I converter of new architecture increased the minimum/maximum current ratio which widens the operation frequency range of VCO's md also guaranteed linearity of VCO's. The proposed PLL circuits in FPD TCON show the measuring performance of loops RMS jitter in the range of $8\sim135MHz$. The designed circuit was fabricated in 1-ploy 3-metal 0.25um TSMC process technology and has a operation range or $8\sim135MHz$ with 2.5V power.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.3 s.357
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• pp.59-64
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• 2007

This paper describes the PLL of TCON(Timing Controller) chip for FPD(Flat Panel Display). We propose a new V-I converter which is insensitive to the power supply variation when it is applied to the TCON. The new V-I converter compensated the output frequency of VCO by appling the current that is inversely proportional to the voltage variation. The proposed idea is implemented with a 1-ploy 3-metal 0.25m TSMC CMOS technology and has the output frequency range from 192MHz to 360MHz at the supply voltage of 2.5V. Measurement result shows the RMS jitter of 100ps in the above output frequency range.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.251-254
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• 1999

In this paper V-I(Voltage to Current) converter using the series composite transistor is presented. Due to the series composite transistor employs operating in the saturation region and triode region, the proposed circuit has wide input range at low voltage. The designed V-I converter has simulated by HSPICE using 0.6${\mu}{\textrm}{m}$ n-well CMOS process with a $\pm$2.5V supply voltage. Simulation results show that the THD can be 0.81% at 4 $V_{p-p}$ differential input voltage when frequency of input signal is 10MHz.z.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.1
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• pp.85-91
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• 2008

A Boost Power Factor Correction (PFC) Converter employing Zero Voltage Switching (ZVS) based Compound Active Clamping (CAC) technique is presented in this paper. An Electro Magnetic Interference (EMI) Filer is connected at the line side of the proposed converter to suppress Electro Magnetic Interference. The proposed converter can effectively reduce the losses caused by diode reverse recovery. Both the main switch and the auxiliary switch can achieve soft switching i.e. ZVS under certain condition. The parasitic oscillation caused by the parasitic capacitance of the boost diode is eliminated. The voltage on the main switch, the auxiliary switch and the boost diode are clamped. The principle of operation, design and simulation results are presented here. A prototype of the proposed converter is built and tested for low input voltage i.e. 15V AC supply and the experimental results are obtained. The power factor at the line side of the converter and the converter efficiency are improved using the proposed technique.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.193-195
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• 2015

본 연구에서는 시스템 내부에 존재하는 불확실성에 대하여 안정성을 만족하는 입력신호 V, I, R, PWM의 신호를 사용자가 선택하는 신호로 변환하여 출력할 수 있는 신호변환기의 성능 및 설계방법을 연구 한다. 본 연구에서는 시간지연이 존재하는 신호변환기를 안정된 입/출력을 수행하여 나타나는 V, I, R, PWM 신호의 시간지연의 영향을 고려한 설계와 그 성능을 평가해 보았다.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.189-197
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• 2017

This paper elaborates two novel proposed topologies (type-I and type-II) of the high step-up DC-DC converter using switched inductor and voltage multiplier cell. The advantages of these proposed topologies are the less voltage stress on semiconductor devices, low device count, high power conversion efficiency, high switch utilization factor and high diode utilization factor. We analyze the Type-II topologies operating principle and mathematical analysis in detail in continuous conduction mode. High-intensity discharge lamp for the automotive application can use the derived topologies. The proposed converters give better performance when compared to the existing types. Also, it is found that the proposed type-II converter has relatively higher voltage gain compared to the type-I converter. A 40 W, 12 V input voltage and 72 V output voltage has developed for the type-II converter and the performances are validated.

• Journal of Power Electronics
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• v.16 no.4
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• pp.1288-1297
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• 2016

This study proposes a single-stage light-emitting diode (LED) tube lamp driver with input-current shaping for T8/T10-type fluorescent lamp replacements. The proposed AC-DC LED driver integrates a dual-boost converter with coupled inductors and a half-bridge series-resonant converter with a bridge rectifier into a single-stage power conversion topology. This paper presents the operational principles and design considerations for one T8-type 18 W-rated LED tube lamp with line input voltages ranging from 100 V rms to 120 V rms. Experimental results for the prototype driver show that the highest power factor (PF = 0.988), lowest input current total harmonic distortion (THD = 7.22%), and highest circuit efficiency (η = 92.42%) are obtained at an input voltage of 120 V. Hence, the proposed driver is feasible for use in energy-efficient indoor lighting applications.