• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1347-1353
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• 2015

We implemented a 10 Gb/s 4-channel vertical cavity surface emission lasers (VCSEL) driver array in a $0.13{\mu}m$ CMOS process technology. To enhance high current resolution, power dissipation, and chip space area, digital APC/AMC with time division sensing technology is primarily adopted. The measured -3 dB frequency bandwidth is 9.2 GHz; the small signal gain is 10.5 dB; the current resolution is 0.01 mA/step, suitable for the wavelength operation up to 10 Gb/s over a wide temperature range. The proposed APC and AMC demonstrate 5 to 20 mA of bias current control and 5 to 20 mA of modulation current control. The whole chip consumes 371 mW of low power under the maximum modulation and bias currents. The active chip size is $3.71{\times}1.3mm^2$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.6
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• pp.25-32
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• 2011

This paper proposes high efficiency current-mode DC-DC buck converter that are suitable for portable devices. The current-mode DC-DC buck converter using adjustable Dead-time control method improves the power efficiency 2~5%. The buck converter has been implemented with a standard 0.35${\mu}m$ CMOS process. The size of this chip is 0.97$mm^2$. The input range of the fabricated DC-DC buck converter is 2.5V~3.3V, and the output is 1.8V. The maximum loading current of the converter is 500mA and the peak efficiency is 93% at 200mA loads.

• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.245-252
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• 2003

We designed a silicon pressure sensor interface circuit with digital calibration capability. The interface circuit is composed of an analog section and a digital section. The analog section amplifies the weak signal from the sensor and the digital section handles the calibration function and communication function between the chip and outside microcontroller that controls the calibration. The digital section is composed of I2C serial interface, memory, trimming register and controller. The I2C serial interface is optimized to suit the need of on-chip silicon microsensor in terms of number of IO pins and silicon area. The major part of the design is to build a controller circuit that implements the optimized I2C protocol. The designed chip was fabricated through IDEC's MPW. We also made a test board and the test result showed that the chip performs the digital calibration function very well as expected.

• The KIPS Transactions:PartC
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• v.19C no.1
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• pp.39-46
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• 2012

In this paper, we propose a key distribution scheme for flexible chipset pairing conditional access system. Chipset pairing conditional access system is the implementation of CA (Conditional Access) module by using both embedded secure chip in a Set-Top Box(STB) and smartcard, and the secure chip embedded in a STB forms a secure channel between the smartcard and the STB. In short, it is the system that a smartcard outputs encrypted CW (Control Word) to the STB, and the STB decrypts an encrypted CW by using the embedded secure chip. The drawback of this chipset pairing conditional access system is that one smartcard is able to be used for only one specified STB since it is the system using the STB bound to a smartcard. However, the key distribution scheme proposed in this paper overcomes a drawback of current chipset pairing conditional access system by using Chinese Remainder Theorem(CRT). To be specific, with this scheme, one smartcard can be used for multiple, not single, STBs, and applied to current chipset pairing without great changes.

• Journal of IKEEE
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• v.25 no.3
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• pp.517-527
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• 2021

This paper presents the phase-shift full-bridge DC-DC converter using the one-chip micom. The proposed converter primary is the full-bridge power topology that operates with the unipolar pulse-width modulation (PWM) by the phase-shift method, and the secondary is the full-bridge full-wave rectifier composed of four diodes. The control of proposed converter is performed by the one-chip micom and its MOSFET switches are driven by the bootstrap circuit. Thus the total system of proposed converter is simple. The proposed converter achieves high-efficiency using the resonant circuit and blocking capacitor. In this paper, first, the power-circuit operation of proposed converter is explained according to each operation mode. And the power-circuit design method of proposed converter is shown, and the software control algorithm on the micom and the feedback and switch drive circuits operating the proposed converter are described, briefly. Then, the operation characteristics of proposed converter are validated through the experimental results of a designed and implemented prototype converter by the shown design and implementation method in this paper. The highest efficiency in the results was about 92%.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.233-234
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• 2007

과거에는 하나의 제어시스템을 구축하기 위해서는 여러 개의 주변소자를 접목시켜서 구현해 왔다. 하지만 근래에 들어서 소형화, 간략화를 통해 계속해서 원 칩 마이크로프로세서의 사용이 늘고 있으며, 통신방식으로는 가장 주목 받고 있는 통신 방식은 이더넷 통신이다. 이더넷은 하나 하나의 시스템이 거미줄처럼 연결되어 결론적으론 하나의 커다란 묶음으로 묶여있는 시스템이다. 때문에 세계 그 어느 장소든지 이더넷에 연결된 시스템은 지구 반대편의 시스템과도 연결이 가능하다. 이더넷을 통해 연결된 시스템은 최대 100Mbps의 빠른 속도로 복수 객체의 동시제어가 가능한 이유등으로 가장 많이 사용되는 추세이다. 본 논문에서는 DSP를 이용하여 3상 AC모터의 속도 제어시스템을 구성하고 이더넷을 통하여 원격제어 및 각 변수의 변화하는 값을 원격 모니터링 하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.727-730
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• 2009

유비쿼터스는 어떤 기기나 사물에 컴퓨터 칩을 내장시켜 각 사물들이 컴퓨터네트워크에 접속되어 통신을 가능하도록 해주는 정보 기술(IT ; Information Technology)을 총칭하는 것으로, 유비쿼터스 환경이란 결국 사물들의 네트워크를 의미한다. 막연한 유비쿼터스를 보다 현실성 있게 접근 할 수 있도록 휴대폰의 SMS기능을 활용한 "제어기(Controller)"를 설계하고 시험 하였다. 사용자가 휴대폰의 문자 메시지(SMS) 신호를 제어기의 중앙처리장치에 전달하고 이 신호를 처리해서 Relay를 ON/OFF 할 수 있도록 구성 되어 Relay에 연결된 외부기기 즉, 조명, 선풍기, 히터 등 가전기기 등의 전원을 ON/OFF한다. 이를 통해서 일반인들도 간단하고 쉽게 원격제어를 체험 할 수 있고 원한다면 얼마든지 다양한 종류의 전기기기 제어를 할 수 있다.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.159-164
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• 2013

Recently the solution integrated of vision and motion controller which are important element in automatiomn system has been many developed. However typically such a solutions has a many case that integrated vision processing and motion control into network or organized two chip solution on one module. We implement one chip solution integrated into vision and motion controller using Zynq-7000 that is developed recently as extended processing platform. We also apply EtherCAT to motion control that is industrial Ethernet protocol which have compatibility for open standardization Ethernet in order to control of motion because EtherCAT has a secure to realtime control and can treat massive data.

• The Journal of the Acoustical Society of Korea
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• v.36 no.2
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• pp.123-129
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• 2017

In this paper, the realization of a directional digital hearing aid was considered. Conventional time domain time delay method was replaced with digital filters in order to make any general-purposed DSP (Digital Signal Processing) chip to produce the similar directivity pattern. Both the time delay algorithm and the digital filter algorithm were initially evaluated by Matlab (Matrix laboratory) for comparison, and it was confirmed by CSR 8675 Bluetooth DSP IC (Digital Signal Processing Integrated Circuit) chip firmware realization. Some remote control features by a smart phone was added to the smart hearing aid for user interface easiness.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2016.11a
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• pp.165.1-165.1
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• 2016

표면활성화 접합은 이종 소재의 표면을 제어하여 직접 접합하는 기술이다. 본 연구에서는 표면활성화 접합을 이용하여 고 방열특성의 LED용 히트스프레더(heat spreader)를 제작하기 위하여 $Al-Al_2O_3$ 복합소재를 제조하였다. LED 제품의 히트스프레더는 LED에서 발생하는 열을 한 곳으로 집중하는 것을 막아 열을 분산하는 금속판을 의미한다. 최근의 LED 제품은 고출력화에 의한 발열량의 급증으로 MCL(Metal Clad Laminate)를 이용하여 LED 칩에서 발생된 열을 외부로 배출하는 모듈구조를 나타내는 경우가 대다수이다. LED에서 열이 증가하게 되면 LED의 효율이 감소하고, 수명이 줄어드는 현상을 보이기 때문에 방열특성은 매우 중요하다. 따라서 고출력화되어 LED 칩에서 발생되는 열을 제어하는 기술이 이슈화 되고 있다. 기존의 히트스프레더 구조는 통상적으로 Al/절연층(폴리머)/Al으로 폴리머의 열전도율이 1W/mk로 고출력화에 의해 급증하는 LED의 발열량을 충분히 해소시키기 어렵다. 본 연구에서는 급증하는 LED의 방열량을 해소시키기 위해서 기존의 Al/폴리머/Al의 구조를 $Al/Al_2O_3/Al$의 구조로 개발하기 위해서 HV-SCDB 기술을 이용한 $Al-Al_2O_3$ 복합소재 제조 및 접합특성에 관하여 연구하였다.