• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.231-232
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• 2016

This paper investigates the design of multi-winding coupled inductor for minimum inductor current ripple. Based on the general circuit model of coupled inductor together with the operating principles of dc-dc converter, the relationship between the ripple size of inductor current and the coupling factor is derived under the different duty ratio. The optimal coupling factor of n-phase multi-winding coupled inductor which corresponds to a minimum inductor ripple current becomes -(1/n-1), i.e. a complete inverse coupling without leakage inductance, as the duty ratio of steady-state operating point approaches 1/n, 2/n, ${\cdots}$ or (n-1)/n. In an opposite manner, the optimal coupling factor value of zero, i.e. zero mutual inductance, is required when the duty ratio of steady-state operating point approaches either zero or one. Therefore, coupled inductors having optimal coupling factor can minimize the ripple current of inductor and inductor size.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.3
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• pp.279-284
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• 2008

We have developed two absolute evaluation technology of inductor using current transformer (CT) comparator. One is the method that the reactance of inductor is obtained by analysing the equivalent circuit of CT with inductor connected to series at secondary terminal of CT. The other is the method that the reactance of inductor is obtained by comparing phase displacement of current flowing on inductor by using CT comparator. These technologies have the advantage to apply up to rated current and voltage of inductor. The method was applied to inductors under test in the range of $100 {\mu}H{\sim}1\;H$. The inductance of the inductor under test obtained in this study are consistent with those measured by LCR meter using the same inductor within an expanded uncertainty (k = 2) in the overall range of inductance.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.18-24
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• 2019

In this paper, expandable bobbin type multiple integrated coupled-inductor applied 4-paralled switching rectifier was proposed. To design the proposed inductor easily, inductance designing formula was derived through magnetic circuit analysis of the 4-paralleled integrated coupled-inductor. Furthermore, to verify practicality of the proposed inductor, it was applied in 600W class 4-paralleled interleaved switching rectifier, and the steady-state characteristics of the proposed inductor and discrete inductors were compared. Consequently, it was showed that the proposed inductor can replace the conventional discrete inductors with alternative electrical characteristic standard, hence miniaturization of the SMPS can be achieved. From the test result, test circuit with the proposed inductor showed maximum 97.1% of power conversion efficiency and under 18W of power loss where the circuit with discrete inductors showed 96.7% and 20W respectively.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.796-800
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• 2004

The main research on this paper is to model on-chip inductor in digital CMOS technology by using the foundry parameters and the physical structure. The s-parameters of a spiral inductor are extracted from the modeled equivalent circuit and then compared to the results obtained from HFSS. The structure and material of the inductor used for modeling in this work is identical with those of the inductor fabricated by CMOS process. To show why the modeled inductor instead of ideal inductor should be used to design a RF system, we designed dual band RF front-end receiver and then compared the results between when using the ideal inductor and using the modeled inductor.

• Journal of Power Electronics
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• v.11 no.4
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• pp.507-511
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• 2011

This paper presents a single-switch buck converter with a ripple-free inductor current. In the proposed converter, the filter inductor current ripple is completely removed by utilizing an auxiliary circuit consisting of an additional winding of the filter inductor, an auxiliary inductor, and an auxiliary capacitor. Moreover, the ripple-free current characteristic is maintained under both light load and full load conditions. The theoretical analysis and performance of the proposed converter were verified with a 110W experimental prototype operating at a 107 kHz switching frequency.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.547-548
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• 2006

In this paper, cost effective parallel-branch inductor has been proposed and developed in order to increase the quality factor of the conventional spiral inductor. This parallel-branch inductor is composed of only two metals. The presented parallel-branch inductor shows 12% improvement in the quality factor with the same area as the conventional inductor. Also, we improve the parallel-branch inductor for high frequency applications.

• Transactions on Electrical and Electronic Materials
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• v.17 no.6
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• pp.369-374
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• 2016

This paper presents a design procedure of an integrated inductor with a magnetic core for power converters. This procedure considerably reduces design time and effort. The proposed design procedure is verified by the development of an inductor model dedicated to the monolithic integration of DC-DC converters for portable applications. The numerical simulation based on the FEM (finite elements method) shows that 3D modeling of the integrated inductor allows better estimation of the electrical parameters of the desired inductor. The optimization of the electrical parameter values is based on the numerical analysis of the influence of the geometric parameters on the electrical characteristics of the inductor. Using the VHDL-AMS language, implementation of the integrated inductor in a micro Buck converter demonstrate that simulation results present a very promising approach for the monolithic integration of DC-DC converters.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.7
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• pp.17-24
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• 1998

We proposed a novel bondwire inductor buried in plastic package for low cost MMIC and characaterized the electrical perofmrance in a wide frequency range using the full-wave analysis of finite element method(FEM), and then we fabricated and measured the scale-up model in order to prove the characteristics. Th ebondwire inductor has higher quality factor and higher cutoff frequency than the conventional spiral inductor designed n the same area as the bondwire inductor. Since the air-bridge process is not requried for the bondwire inductor, it is very suitable for low cost plastic-packaged MMIC production. The bondwire inductor has the field distribution localized around the bondwire inductor and hence is more compatible to the crosstalk problems.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.2
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• pp.363-368
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• 2009

In the paper, we confirmed improvement Noise figure of the entire RF front-end using spiral inductor with PGS(Patterned Ground Shield) and current bleeding techniques. LNA design is to achieve simultaneous noise and input matching. Spiral inductor in input circuit of LNA inserted PGS for betterment of Q-factor. we modeling inductor using EM simulator, so compared with inductor of TSMC 0.18um. We designed and simulation the optimum structure of PGS using Taguchi's method. We confirmed enhancement of noise figure at LNA after substituted for inductor with PGS. Mixer designed using current bleeding techniques for reduced noise. We designed LNA using inductor with PGS and Mixer using current bleeding techniques, so confirmed improvement of noise figure.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.10
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• pp.534-539
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• 2006

An integrated inductor using the low-temperature co-fired ceramics(LTCC) technology for low-power electronics was fabricated. In the inductor NiZn ferrite sheet$({\mu}_r=230)$, was embedded to increase inductance. The inductor has Ag spiral coil with 14 turns$(7turns{\times}2layers)$, a dimension of 0.6mm in width, 10um in thickness, and 0.15mm pitch. To evaluate the inductance, including the parasitic resistance, the fabricated inductor was calculated and measured. It was confirmed that calculated values were very close to the measured values. Finally as an application of the LTCC integrated inductor to low power electronic circuits, a LTCC boost DC/DC converter with 1W output power and up to 0.5MHz switching frequency using the inductor fabricated was developed.