• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.9
• /
• pp.750-757
• /
• 2002

A new lateral trench LTEIGBT with p+ diverter was proposed to suppress latch-up of LTIGBT The p+ diverter was placed between the anode and cathode electrode. The latch-up of LTEICBT with a p+ diverter was effectively suppressed to sustain an anode voltage of 8.7V and a current density of 1453A/$\textrm{cm}^2$ while in the conventional LTIGBT, latch-up occured at an anode current density of 540A/$\textrm{cm}^2$. In addition, the forward blocking voltage of the proposed LTEIGBT with a p+ diverter was about 140V. The forward blocking voltage of the conventional LTIGBT of the same size was no more than 105V, We fabricated the proposed LTEIGBT with a p+ diverter after the device and process simulation was finished. When the gate voltage is applied 12V, the forward conduction currents of the proposed LTEIGBT with a p+ diverter and the conventional LIGBT are 90㎃ and 70㎃, respectively, at the same breakdown voltage of 150V.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.12 no.3
• /
• pp.114-123
• /
• 1998

The multi-resonant converter(MRC) minimizes a parasitic oscillation by using the resonant tank circuit absorbed parasitic reactances existing in a converter circuit. So it si possible that the converter operated at a high frequency has a high efficiency because the losses are reduced. Such a MHz high frequency applications provide a high power density [W/inch3] of the converter. But the resonant voltage stress across a switch of the resonant tank circuit is 4~5 times a input voltage. This h호 voltage stress increases the conduction loss because of on-resistance of a MOSFET with higher rating. Thus, in this paper we proposed the alternated multi-resonant converter (AT MRC) differ from the clamp mode multi-resonant converter and applicated it to the forward MRC. The AT forward MRC can reduce the voltage stress to 2~3 times a input voltage by using two series input capacitor. The control circuit is simple because tow resonant switches are driven directly by the output pulse of the voltage controled oscillator. This circuit type is verified through the experimental converter with 48V input voltage, 5V/50W output voltage/power and PSpice simulation. the measured maximum voltage stress is 170V of 2.9 times the input voltage and the maximum efficiency of 81.66% is measured.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.1
• /
• pp.177-182
• /
• 2010

The forward convener is one of power supplies used widely. This paper presents parameter tuning methods to obtain optimal circuit element values for the forward converter to minimize the output voltage variation under various load changing environments. The conventional method using the concept of the phase margin is extended to have optimal phase margin that gives slightly improved performance in the output voltage response. For this, the phase margin becomes the tuning parameter and is optimized with the genetic algorithm. Next, the circuit element values are directly chosen as the tuning parameters and also optimized using the genetic algorithm to have very improved performance in the output voltage control of the forward converter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.07a
• /
• pp.9-12
• /
• 2004

In this paper, a new small sized Lateral Trench Electrode Power MOS was proposed. This new structure, called LTEMOS(Lateral Trench Electrode Power MOS), was based on the conventional lateral power MOS. But the entire electrodes of LTEMOS were placed in trench oxide. The forward blocking voltage of the proposed LTEMOS was improved by 1.5 times with that of the conventional lateral power MOS. The forward blocking voltage of LTEMOS was about 240 V. At the same size, an improvement of the forward blocking voltage of about 1.5 times relative to the conventional MOS was observed by using ISE-TCAD which was used for analyzing device's electrical characteristics. Because all of the electrodes of the proposed device were formed in each trench oxide, the electric field was crowded to trench oxide and punch-through breakdown was occurred, lately.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.980-982
• /
• 2002

In this paper, we report the experimental results of the Forward-flyback DC-DC converter with current doubler and synchronous rectifier. The experimental converter, that has a output voltage 1.8V, output current 25A, maximum power of 45W, switching frequency of 290kHz and input voltage range of 36-75V, has been successfully implemented. As a result, in the entire voltage range the measured full load efficiency was above 82%, and the output voltage was regulated at 1.8V within ${\pm}$3% tolerance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1998.06a
• /
• pp.87-91
• /
• 1998

In this paper, We analyzed the current-voltage characteristics with n-type silicon substrates concentration and temperature variations (Room temperature, 50$^{\circ}C$, 75$^{\circ}C$) in platinum silicide and silicon junction. The electrical parameters of measurement are turn-on voltage, saturation current, ideality factor, barrier height, dynamic resistance in forward bias and reverse breakdown voltage according to variations of junction concentration of substrates and measurement temperature variations. As a result, the forward turn-on voltage, reverse breakdown voltage, barrier height and dynamic resistance were decreased but saturation currents and ideality factor were increased by substrates increased concentration variations in platinum silicide and n-silicon junction. In increased measurement temperature (RT, 50$^{\circ}C$, 75$^{\circ}C$), the extracted electrical parameter values of characteristics were rises by increased temperature variations according to the forward and reverse bias.

• Journal of Power Electronics
• /
• v.18 no.2
• /
• pp.356-363
• /
• 2018

The combination of a buck converter and a forward converter can be considered to accomplish a high step-down non-isolated converter. To decrease the insufficient step-down ratio of a regular buck converter and to distribute switch voltage stress, a forward-integrated buck (FIB) converter is proposed in this paper. The proposed interleaved DC-DC converter provides an additional step-down gain with the help of a forward converter. In addition to its simple structure, the transformer flux reset problem is solved and an additional magnetic core reset winding is not required. The operational principle and an analysis of the proposed FIB converter are presented and verified by experimental results obtained with a 240 W, 150 V/24 V prototype.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.05a
• /
• pp.66-69
• /
• 2008

In this paper, The author present a load current feed-forward compensator by method that improve voltage controller of Step-down Chopper to get stable output voltage to sudden change of load current. To confirm the characteristicsof a presented load current feed -forward compensator compared each transfer function of whole system that load current feed-forward compensator is added with transfer function of whole system that existent voltage controller is included using Mason gains formula in Root locus and Bode diagram. As a result the pole of system is improved, extreme point of the wave and system improves, and size of peak value and phase margin of break frequency in resonance frequency confirmed that is good. Therefore, presented control technique could confirm that reduce influence by perturbation and improves stationary state and dynamic characteristics in output of Step-down Chopper.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.276-280
• /
• 2003

This paper presents a zero voltage and zero current switching (ZVZCS) interleaving two-transistor forward converter for high input voltage and high power application. A phase shift has a disadvantage that a circulating current and RMS current stress, conduction losses of transformer and switching devices increases. Due to this circulating current and RMS current stress, conduction losses of transformer and switching devices increases. To alleviate these problems, we propose an improved interleaving two-transistor forward Zero Voltage and Zero Current Switching (ZVZCS) dc/dc converter using a tapped inductor a snubber capacitor and two snubber diodes attached at the secondary side of transformer. The proposed ZVZCS converter is verified on a 1.8kW, 5kHz experimental prototype.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.40 no.6
• /
• pp.393-399
• /
• 2003

The current paper presents a new Mo-MPS rectifier using molybdenum as barrier metal to improve on the low forward voltage drop and power dissipation of the coventional Al-MPS and Pt-MPS rectifier. Electrical characteristics of the fabricated Mo-MPS rectifier are imvestigated compared with Al-MPS and Pt-MPS rectifier. At the same current level, the forward voltage drop of the Mo-MPS was reduced by 0.11V~0.24V compared to that of the conventional MPS rectifier. Accordingly, since the Power dissipation of a rectifier mostly depends on the forward current density and forward voltage drop, the Mo-MPS rectifier achieved improved power dissipation when compared to the conventional MPS rectifier. The reverse breakdown voltage of a Mo-MPS rectifier with 68% Schottky junction area was about 304y. Despite having a lower forward voltage drop than a conventional MPS rectifier, the Mo-MPS rectifier still exhibited a higher reverse breakdown voltage.