• Journal of IKEEE
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• v.19 no.3
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• pp.304-310
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• 2015

A SCALDO(Supercapacitor Assisted LDO) regulator is a new regulator having advantages of a SMPS(Switch Mode Power Supply) which has a good efficiency and a LDO(Low Drop-out) regulator which has stable output characteristics and good EMI(Electro Magnetic Interference) characteristics. However, a conventional SCALDO regulator needs a lot of power consumption to control its switches and it drops an efficiency of the circuit. In this paper, to reduce switching power consumption and improve an efficiency of the circuit, a new SCALDO regulator adopting MOSFETs as its switching parts is proposed and it is found out that the proposed SCALDO regulator has the maximum 9.5% higher efficiency than the conventional SCALDO regulator. We also try to simplify production process of the circuit by changing switching control method of the circuit from MCU(Micro-controller unit) based firmware control to hardware control using a comparator and a T-F/F(Flip Flop).

• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.97-105
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• 2020

Recently, as the data speed and operating frequencies of Ethernet keeps increasing, electro magnetic interference (EMI) also becomes increasing. The generation of such EMI will cause malfunction of near electronic devices. In this study, EMI filters were applied to reduce the EMI generated by DC-DC SMPS (switching mode power supply), which is the main cause of EMI generation of Ethernet switch. As the EMI filter, MLCCs with excellent withstanding voltage characteristics were used, which had advantages in miniaturization and mass production. Two types of EMI MLCC filters were used, which are X-capacitor and X, Y-capacitor. X-capacitor was composed of 2 MLCCs with 10 nF and 100 nF capacity and 1 Mylar capacitor. Y-capacitor was consisted of 6 MLCCs with a capacity of 27 nF. When only X-capacitor was applied as EMI filter, the conductive EMI field strength exceeded the allowable limit in frequency range of 150 kHz ~ 30 MHz. The radiative EMI also showed high EMI strength and very small allowable margin at the specific frequencies. When the X and Y-capacitors were applied, the conductive EMI was greatly reduced, and the radiation EMI was also found to have sufficient margin. In addition, X, Y-capacitors showed very high insulation resistance and withstanding resistance performances. In conclusion, EMI X, Y-capacitors using MLCCs reduced the EMI noise effectively and showed excellent electrical reliability.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.2
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• pp.114-121
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• 2016

This paper is Instant space vector PWM(Pulse Width Modulation)power conversion devices in switching power semiconductors from my generation to losses and switching when the voltage surge and current surge of electronic noise(EMI: Electro Magnetic Interference / RFI: Radio Frequency Interference)to effectively minimize the power soft-switching power conversion circuit topologies of auxiliary resonant DC tank for the purpose of high performance realization of the electric power conversion system by the high-speed switching of a semiconductor device(AQRDCT simultaneously : an active auxiliary resonance using auxiliary Quasi-resonant DC tank)DC link snubber switch has adopted a three-phase voltage inverter. AQRDCL proposed in this paper can reduce the effective and current peak stress of the power semiconductors of the auxiliary resonant snubber circuit compared to the conventional active-resonant DC link snubber, it is not necessary to install the clamp switch of the auxiliary resonant DC link, DC the peak current and power loss of the bus line can be reduced.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.211-214
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• 2002

In this paper, We have investigated the EMI (electro magnetic interference) characteristics of electrodeless fluorescent lamp ballast as a ground connection and have measured various waveforms, which can be expressed the disturbance voltages and radiated electromagnetic disturbances. induced the measuring instrument and found that effect of ground connection is the one of the important elements on EMI reduction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.1049-1057
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• 2017

In-vehicle multimedia systems are one of the most important factors in the automotive industry. Especially, multimedia systems are more important in advanced commercial vehicles such as premium express buses. In this paper, we proposed a multimedia streaming system architecture using MEP(MOST Ethernet Packets) for premium express buses based on MOST150. We have designed and implemented the prototype of proposed multimedia streaming system. We have designed a board based on i.MX6 to operate a proposed multimedia streaming system. The software has designed a multimedia system for premium express buses based on Android which is an open source platform. MOST(Media Oriented Systems Transport) is a high-speed multimedia network technology for in-vehicle multimedia system. The MOST network is able to manage up to 64 devices and ring topology is used basically. In addition, the MOST Network meets EMI(Electro-Magnetic Interference)/ EMC(Electro-Magnetic Compatibility) requirements because it uses plastic optical fibers(POF).

• Journal of Power Electronics
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• v.18 no.3
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• pp.923-930
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• 2018

Based on the application of an integrated dynamic brake (IDB) system that uses a PWM inverter fed-AC motor drive to operate the piston, a new active zero state PWM (AZSPWM) is proposed to improve the stability and reliability of the IDB system by suppressing the conducted electro-magnetic interference (EMI) noise under a wide range of load torque. The new AZSPWM reduces common-mode voltage (CMV) by one-third when compared to that of the conventional space vector PWM (CSVPWM). Although this method slightly increases the output current ripple by reducing the CMV, like the CSVPWM, it can be used within the full range of the load torque. Further, unlike other reduced common-mode voltage (RCMV) PWMs, it does not increase the switching power loss. A theoretical analysis is presented and experiments are performed to demonstrate the effectiveness of this method.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.05a
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• pp.202-206
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• 2003

전자파(Electromagnetic wave)는 인간이 사용하고 있는 모든 전기·전자제품에 의해 발생되는 전기장과 자기장을 의미하며 첨단과학기술의 발전과 함께 전기, 전자, 통신관련 기기의 사용이 급증함에 따라 전자파는 다른 전자기기의 심각한 전파장애와 인체에 유해한 요소로 작용하고 있다. 이러한 피해현상을 EMI(Electro Magnetic Interference)라 하며 소형화, 고집적화, 다기능화를 지향하는 현대 전기, 전자, 통신산업에 있어서 치명적인 장애요소로 대두되고 있다.(중략)

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2295-2297
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• 2003

The major problem encountered in satellite design is EMI (Electro-Magnetic Interference) and EMC (Electro-Magnetic Compatibility). Here, our focus is on the effects of protons on the electronic system. The SEU (Single Event Upset) results from the level change of stored information due to photon radiation and temperature in the space and the nuclear power plant environment. The impact of SEU on PLD (Programmable Logic Devices) technology is most apparent in ROM/SRAM/DRAM devices wherein the state of storage cell can be upset. In this paper, a simple and powerful test techniques is suggested, and the results are presented for the analysis and future reference. The test results are compared with that of JPL test report. In our experiment, the proton radiation facility available at KIRAMS (Korea Institute of Radiological Medical Sciences) has been applied on a commercially available SRAM manufactured by Hynix Semiconductor Company.

• International Journal of Aeronautical and Space Sciences
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• v.5 no.2
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• pp.28-34
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• 2004

One of the major problem encountered in nuclear plants and satellites design isEMI (Electro-Magnetic Interference) and EMC (Electro-Magnetic Compatibility).Here, our focus is to implement the test board for checking SEU (Single EventUpsets); the effects of protons on the electronic system. The SEU results from thelevel change of stored information due to photon radiation and temperature in thespace environment. The impact of SEU on PLD (Programmable Logic Devices)technology is most apparent in ROM/SRAM/DRAM devices wherein the state ofstorage cell can be upset. In this paper, a simple and powerful test techniques issuggested, and the results are presented for the analysis and future reference. In ourexperiment, the proton radiation facilitv (having the energy of 50 MeV with a beamcurrent of 60 uA of cyclotron) available at KIRAMS (Korea Institute of RadiologicalMedical Sciences) has been applied on a commercially available SRAM manufacturedby Hynix Semiconductor Company.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.521-522
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• 2008

21세기를 접하면서 산업전자 분야의 비약적인 발전과 함께 과학문명은 눈부시게 발전해 나아가고 있다. 이것의 원천은 바로 전기(Electric)이다. 우리는 풍요로운 삶 자체를 전기 공급에서 누리고 있으며 또 비극적인 사태를 맞이할 때도 있다. 즉, 전기기기를 이용하면 원하건 원치 않건 전자기파가 발생이 된다 이것이 자연현상이며 전자기파는 IT, BT, CT를 비롯하여 산업 전체에 많은 영향을 미치고 있다. 일반적으로 우리가 말하는 전자기파 장해의 기본 요소는 노이즈원(잡음원), 경로매체, 피해장치 등으로 구성되는 데 잡음원(Noise Source)은 각종 시스템에서 구성되고 있는 전자기 에너지의 발생원으로 볼 수 있으며 이 발생원에서 경로매체(금속:전도성, 대기중:전파성 등)를 통하여 피해장치(전기전자통신기기류)에 방해를 주고 있는 상태를 전자기파 장해라고 설명할 수 있다. 전자기파 잡음원에서 경로를 거쳐 전자기파에 대하여 피해장치가 안정된 상태로 동작하도록 규정하는 용어 즉, 전자파 양립성 또는 적합성 (EMC : Electro Magnetic Compatibility))이란 용어를 가지고 전기 전자 통신기기에서 발생되는 불필요한 전자파와 전자파 내성시험을 만족하도록 의무화하고 있다. EMC 는 EMI (불요 전자파 또는 전자파 간섭 : Electro Magnetic Interference) + EMS (전자파 내성 : Electro Magnetic Susceptibility) 2가지 시험을 함께 전자파 적합성 (EMC) 시험으로 표현되고 있다. 전자파 적합성 시험의 목적으로 EMl는 전도성 또는 전파성에 대한 주파수 대역(잡음)을 보호하기 위한 것이 목적이고 EMS는 프로세서가 내장된 기기류의 오동작을 방지하기 위하여 감응평가를 하는 것이다. 즉, 감응(Susceptibility)이란 어떤 장비나 시스템이 전자기파 장해에 쉽게 영향을 받는 것을 뜻하는 데 전자파 장해를 견디면서 본래의 기능을 충분하게 발휘하며 동작할 수 있는 능력을 말한다.