• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.20-23
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• 2008

We proposed a-Si:H TFT (hydrogenated amorphous silicon thin film transistor) level shifter which reduced number of power sources. To reduce the number of power sources from four to two, modified bootstrapped inverter was used for the level shifter. The shift register was verified by PSPICE circuit simulation and fabricated. The fabricated level shifter successfully shifted low input (0 to 5 V) to high level output (-7 to 23 V).

• Journal of Information Display
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• v.11 no.1
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• pp.21-23
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• 2010

A new level shifter using low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs) for low-power applications is proposed. The proposed level shifter uses a capacitive-coupling effect and can reduce the power consumption owing to its no-short-circuit current. Its power saving over the conventional level shifter is 72% for a 3.3 V input and a 10 V output.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.747-750
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• 2005

In this paper, we propose a new level shifter circuit for reducing power consumption. The concept of the proposed level shifter is to use capacitive coupling effect to reduce short circuit current. The power consumption of the proposed level shifter is reduced up to 50%, compared to the conventional level shifter. Especially the proposed level shifter circuit works well with low temperature poly-Si (LTPS) TFTs. It can operate on low input voltage even with low-mobility, high and widely-varying threshold voltage of LTPS TFT.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.719-726
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• 2008

In this paper, we designed driving IC for 500 V resonant half-bridge type power converter, In this single-ended level shifter, chip area and power dissipation was decreased by 50% and 23.5% each compared to the conventional dual-ended level shifter. Also, this newly designed circuit solved the biggest problem of conventional flip-flop type level shifter in which the power MOSFET were turned on simultaneously due to the large dv/dt noise. The proposed high side level shifter included switching noise protection circuit and schmmit trigger to minimize the effect of displacement current flowing through LDMOS of level shifter when power MOSFET is operating. The designing process was proved reasonable by conducting Spectre and PSpice simulation on this circuit using 1${\mu}m$ BCD process parameter.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.25-31
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• 2008

We propose a low power level-up/down shifter with single supply that can be used at SoC with multiple supply. The proposed circuit interfaces IPs which are operated on the different supply voltages. The circuit is designed with a single supply that decreases the low power consumption and the complexity of supply routing and layout. The proposed circuit operated at 500MHz for level-up and at 1GHz for level-down. The level-up/down shifter improves noise immunity of the system at I/O circuit. The circuit is evaluated for 1.8V, 2.5V, 3.3V supply with 0.18um CMOS technology, respectively.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.6 s.348
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• pp.9-17
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• 2006

We proposed a new High-speed CMOS Level Up/Down Shifter circuits that can be used with Dynamic Voltage and Frequency Scaling(DVFS) algorithm, for low power system in the SoC(System-on-Chip). This circuit used to interface between the other voltage levels in each CMOS circuit boundary, or between multiple core voltage levels in a system bus. Proposed circuit have advantage that decrease speed attenuation and duty ratio distortion problems for interface. The level up/down shifter of the proposed circuit designed that operated from multi core voltages$(0.6\sim1.6V)$ to used voltage level for each IP at the 500MHz input frequency The proposed circuit supports level up shifting from the input voltage levels, that are standard I/O voltages 1.8V, 2.5V, 3.3V, to multiple core voltage levels in between of $0.6V\sim1.6V$, that are used internally in the system. And level down shifter reverse operated at 1Ghz input frequency for same condition. Simulations results are shown to verify the proposed function by Hspice simulation, with $0.6V\sim1.6V$ CMOS Process, $0.13{\mu}m$ IBM CMOS Process and $0.65{\mu}m$ CMOS model parameters. Moreover, it is researched delay time, power dissipation and duty ration distortion of the output voltage witch is proportional to the operating frequency for the proposed circuit.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1015-1018
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• 2004

We proposed a new cross-coupled level shifter circuit using low temperature poly-Si(LTPS) TFT. The proposed level shifter can operate on low input voltage in spite of low mobility and widely varying high threshold voltage of LTPS TFT. Also, the proposed level shifter operates at high frequency and reduces power consumption for having fast rising and falling time and shortening period flowing short-circuit currents.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.9
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• pp.49-57
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• 2009

In this paper, we propose a multiple voltage scheduling method which reduces energy consumption considering both timing constraints and resource constraints. In the other multiple voltage scheduling techniques, high voltage is assigned to operations in the longest path and low voltage is assigned to operations that are not on the longest path. However, in those methods, voltages are assigned to specific operations restrictively. We use a simulated annealing technique, in which several voltages are assigned to specific operations flexibly regardless of whether they are on the longest path. In this paper, a post processing algorithm is proposed to further reduce the energy consumption. In some cases, designers may want to reduce the level shifters. To make tradeoff between the total energy and the number (or energy) of level shifters weighted term can be added to the cost function. When the level shifter energy is weighted six times, for example, the number of level shifters is reduced by about 24% and their energy consumption is reduced by about 20%.

• Nuclear Engineering and Technology
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• v.33 no.2
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• pp.201-208
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• 2001

The high power RF transmission line components are required for transmitting MW level RF power continuously in RF heating and current drive system which heat the plasma and produce plasma current in fusion reactor The liquid stub and phase shifter is proposed as the superior to the conventional stub and phase shifter. Experimental results show that they are reliable and easy to operate compared to the conventional stub and phase shifter. There is no distortion of reflected power during the raising of the liquid level. RF breakdown voltage is over 40kV. Temperature increment of the liquid is expected not to be severe. These results verify that the liquid stub and phase shifter can be used reliably in the high power continuous RF facilities.

• Journal of Electrical Engineering and Technology
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• v.11 no.1
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• pp.125-134
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• 2016

We propose an efficient high voltage level shifter for a high side Buck converter driving a light-emitting diode (LED) lamp. The proposed circuit is comprised of a low voltage pulse width modulation (PWM) signal driver, a coupling capacitor, a resistor, and a diode. The proposed method uses a property of a PWM signal. The property is that the signal repeatedly transits between a low and high level at a certain frequency. A low voltage PWM signal is boosted to a high voltage PWM signal through a coupling capacitor using the property of the PWM signal, and the boosted high voltage PWM signal drives a p-channel metal oxide semiconductor (PMOS) transistor on the high side Buck converter. Experimental results show that the proposed level shifter boosts a low voltage (0 to 20 V) PWM signal at 125 kHz to a high voltage (370 to 380 V) PWM signal with a duty ratio of up to 0.9941.