• Transactions on Electrical and Electronic Materials
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• v.17 no.5
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• pp.270-274
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• 2016

This article investigates the use of the Gaussian-channel doping profile for the control of the short-channel effects in the double-gate MOSFET whereby a two-dimensional (2D) quantum simulation was used. The simulations were completed through a self-consistent solving of the 2D Poisson equation and the Schrodinger equation within the non-equilibrium Green’s function (NEGF) formalism. The impacts of the p-type-channel Gaussian-doping profile parameters such as the peak doping concentration and the straggle parameter were studied in terms of the drain current, on-current, off-current, sub-threshold swing (SS), and drain-induced barrier lowering (DIBL). The simulation results show that the short-channel effects were improved in correspondence with incremental changes of the straggle parameter and the peak doping concentration.

• Proceedings of the KIEE Conference
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• 2005.11b
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• pp.49-51
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• 2005

The saturation of transformer for short-circuit test suppress the peak current value during the test. And such phenomenon effect on the test results occasionally. This paper deals with the induction of the formula to restore the peak current value from the measured data.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.3
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• pp.331-338
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• 2014

A charge-pump circuit using a current-bypass technique, which suppresses charge sharing and reduces the sub-threshold currents, helps to decrease phase-locked loop (PLL) jitter without resorting to a feedback amplifier. The PLL shows no stability issues and no power-up problems, which may occur when a feedback amplifier is used. The PLL is implemented in 0.11-${\mu}m$ CMOS technology to achieve 0.856-ps RMS and 8.75-ps peak-to-peak jitter, which is almost independent of ambient temperature while consuming 4 mW from a 1.2-V supply.

• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.4
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• pp.241-246
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• 2007

This paper presents two novel compensation circuits for leakage current and power supply noise (PSN) in phase locked loop (PLL) using a nanometer CMOS technology. The leakage compensation circuit reduces the leakage current of the charge pump circuit and the PSN compensation circuit decreases the effect of power supply variation on the output frequency of VCO. The PLL design is based on a 32nm predictive CMOS technology and uses a 0.9 V power supply voltage. The simulation results show that the proposed PLL achieves 88% jitter reduction at 440 MHz output frequency compared to the PLL without leakage compensator and its output frequency drift is little to 20% power supply voltage variations. The PLL has an output frequency range of 40 $M{\sim}725$ MHz with a multiplication range of 1-1023, and the RMS and peak-to-peak jitter are 5psec and 42.7 psec, respectively.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.313-316
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• 2002

A SRM inverter has very low switching frequency. This results in reducing the burden for a high-speed of the gate-amp interface circuit. and the linearity of optocoupler is used to protect the intanteneous peak current for the stable operation In this paper, series resistor is used to equal the current sharing of each switching device and a linear gate-amp is proposed to protect the intanteneous peak current which occurs in transient state.

• Journal of Power Electronics
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• v.18 no.3
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• pp.879-891
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• 2018

A bidirectional dc-dc converter is used in battery energy storage systems owing to the growing requirements of a charging and discharging mode of battery. The magnetic coupling of output or input inductors in parallel-connected multi modules of a bidirectional dc-dc converter is often utilized to reduce the peak-to-peak ripple size of the inductor current. This study proposes a novel design guideline to achieve minimal ripple size of the inductor current under bidirectional power flow. The newly proposed design guideline of optimized coupling factor is applicable to the buck and boost operation modes of a bidirectional dc-dc converter. Therefore, the coupling factor value of the coupled inductor does not have to be optimized separately for buck and boost operation modes. This new observation is explained using the theoretical model of coupled inductor and confirmed through simulation and experimental test.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.5
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• pp.157-163
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• 1983

Positive and negative coronas in point-to-plane short gap have been investigated with the variations of point radius and gap length. Mainly the onset potentials and current pulses under various conditions were measured with a 70 MHz C.R.O. and a precise-controllable D.C. power supply. In the case of negative corona, the Trichel pulse corona, glow corona and spark regions were distinguished apparently and the critical gap lengths between them were also found clearly. In the case of positive corona, there are streamer corona, spark regions and the critical gap length between them, too. The current pulse forms of Trichel pulse corona of negative and streamer pulse corona of positive are similar in rising time, peak-to-peak time and pulse width. The glow corona current shows D.C. component in form.

• Electrical & Electronic Materials
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• v.10 no.4
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• pp.334-341
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• 1997

Streaming electrification on insulating paper and pressboard under D.C. and A.C. electric field was investigated by using paper tubes and oil circulation apparatus. At first, flowing of static charges as measured with no electric field. As the temperature of oil increased, the measured current curve hows peak. As the velocity increased, it shows increasing exponential curve. Then, we applied A.C. and D.C. electric field on paper tube and the current from relaxation tank to earth was measured, which other factors such as temperature and velocity were varied like case of no electric field. The ions in oil carry the charges. So electric field makes asymmetry effect, and electrophoretic effect on ions in oil. We find that as the electric field intensity increased, the charges which were made by electric double layer were increased. The charge vs. velocity curve made peak point at a velocity.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1061-1064
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• 2009

Through dark injection space-charge-limited current (DI-SCLC) and trap-free SCLC measurements, it has been demonstrated that an indium tin oxide (ITO)/buckminsterfullerene ($C_{60}$) electrode can form a quasi-Ohmic contact with N, N'-bis (naphthalen-1-yl)-N, N'-bis(phenyl) benzidine (NPB). The DI-SCLC results show a clear peak current along with a shift of the peak position as the field intensity varies, implying an Ohmic (or quasi-Ohmic) contact. A theoretical simulation of the SCLC also shows that ITO/$C_{60}$ forms an Ohmic contact with NPB. The Ohmic contact makes it possible to estimate the NPB hole mobility through the use of both DI-SCLC and trap-free SCLC analysis. This also contributes to a reduction in power consumption.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.1-2
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• 2016

This paper presents frequency modulation method of zero-voltage-transition interleaved DC/DC converter using auxiliary coupled-inductor. In conventional ZVT interlaved converter without semi-conductor devices in auxiliary circuit, the peak-to-peak value of coupled-inductor current has fixed value despite the change of load current. Then, as the load is reduced, the efficiency is reduced because of the conduction loss. The proposed frequency modulation method can reduce the conduction loss by controlling the current of coupled-inductor as the load condition using frequency modulation. The proposed method is verified by experimental results.