• Journal of information and communication convergence engineering
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• v.9 no.1
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• pp.78-82
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• 2011

This paper proposes a new circuit for capacitive sensing based on Dickson's charge pump. The proposed touch sensing circuit includes three stages of NMOS diodes and capacitors for charge transfer. The proposed circuit which has a simplified capacitive touch sensor model has been analyzed and simulated by Spectre using Magna EDMOS technology. Looking from the simulation results, the proposed circuit can effectively be used as a capacitive touch sensing circuit. Moreover, a simple structure can provide maximum flexibility for making a digitally-controlled touch sensor driver with lowpower operations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.2
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• pp.319-324
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• 2012

This paper introduces a 2-dimensional touch screen panel driver based on an improved capacitive sensing circuit. The improved capacitive sensing circuit based on charge pump can eliminate the remaining charges of the intermediate nodes, which may cause output voltage drift. The touch screen panel driver with mixed-mode circuits was built and simulated using Cadence Spectre. Verilog-A models the digital circuits effectively and enables them to interface with analog circuits easily. From the simulation results, we can verify the reliable operations of the simple structured touch screen panel driver based on the improved capacitive sensing circuit offering no voltage drift.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.54-57
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• 2009

The propellant level measurement system of the next Koreanized launch vehicle shall adapt a capacitive type sensor, which can generate capacitive values continuously considering cryogenic environment and the characteristics of flowrate control. At present there are a twin-arc and a triple-arc methods as a capacitive type signal sensing method. In this study a highly accurate triple-arc method, which can apply to almost all fluids, is chosen. In this paper the review results on the principle of triple-arc sensing, the analysis results on the influence on capacitive values due to shape change of sensing part, and the simulation results to monitor the influence on signal sensing according to the location of sensing part in the upper part of propellant tank are included. Information obtained from this study can be used in the designing and manufacturing of on-board propellant level measurement system in tanks.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.4
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• pp.26-33
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• 2010

This paper presents a multi-channel capacitive touch sensing unit for SoC applications. This unit includes a simple common processing unit and switch array to detect the touch sensing input by capacitive-time(C-T) conversion method. This touch sensor ASIC is designed based on the Capacitive-Time(C-T) conversion method to have advantages of small current and chip area, and the minimum resolution of the unit is 41 fF per count with the built-in sensing oscillator, LDO regulator and $I^2C$ for no additional external components. This unit is implemented in 0.18 um CMOS process with dual supply voltage of 1.8 V and 3.3 V. The total power consumption of the unit is 60 uA and the area is 0.26 $mm^2$.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.7
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• pp.778-783
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• 2013

Measurement of liquid level in storage and processing vessels, tanks, wells, reservoirs and hoppers is commonly needed. The several different ways to measure the liquid level of oil or water tank have been provided such as an electrostatic capacity, a supersonic waves and an optical science etc. In the study, we have constructed the stable and efficient measurement system to measure the level of liquid at real-time and to get accurate measurement of the maximum and minimum level of the tank. For this purpose, we suggest double sensing methods by adopting both capacitive and optical sensing. The experimental results, presented in this paper, illustrate the effectiveness of the proposed method under different sensing methods.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.537-537
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• 2010

High precision sensing is very important in various technologies. Especially, it is more important when it were applied to nano/micro meter level's sensing like AFM, storage, etc. And capacitive sensing is widely used method. To improve the measurement efficiency, many signal conditioners were studied and one of them was surface acoustic wave (SAW) device. SAW device is very widely used as a high frequency bandwidth filter. Due to the reflective characteristic of high frequency, the response of SAW device contains both propagative and reflective signal at the external impedance. In this paper, we used SAW device as signal conditioner of capacitive sensor. And high precision gap measurement was executed using capacitive load. Reference signal was reflective SAW response and the magnitude at the center frequency of SAW device by the change of impedance was checked. Finally, the attainable gap resolution was determined.

• Journal of Sensor Science and Technology
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• v.26 no.1
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• pp.60-65
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• 2017

This paper describes the low noise and low power IC using the opamp sharing technique for the capacitive micro-sensor sensing platform. The proposed IC reduces noise using correlated double sampling (CDS) and reduces power consumption using the opamp sharing technique. The IC is designed to be fully programmable, and can be digitally controlled by serial peripheral interface (SPI). The power consumption and the integrated input referred noise are 1.02 mW from a 3.3 V supply voltage and $0.164aF_{RMS}$ with a bandwidth of 400 Hz. The capacitive sensitivity, the input-output linearity and the figure of merits (FoM) are 2.5 mV/fF, 2.46 %FSO, and 8.4, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.4
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• pp.39-46
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• 2009

In this paper, we propose a full digital capacitive sensing touch key reducing the effects due to the variations of resistance and clock frequency. The proposed circuit consists of two capacitive loads to measure and a resistor between the capacitive loads. The method measures the delays of the resistor and two capacitive loads, respectively. The ratio of the two delays is represented as the ratio of the two capacitive loads and is irrelative to the resistance and the clock frequency if quantization error is disregarded. Experimental results show the proposed scheme efficiently reduces the effects due to the variations of clock frequency and resistance. Further more the method has l.04[pF] resolution and can be used as a touch key.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.8
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• pp.80-85
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• 2009

In this paper, we propose a full digital capacitive sensing touch key reducing the effects due to the variations of resistance and clock frequency. The proposed circuit consists of two capacitive loads to measure and a resistor between the capacitive loads. The method measures the delays of the resistor and two capacitive loads, respectively. The ratio of the two delays is represented as the ratio of the two capacitive loads and is irrelative to the resistance and the clock frequency if quantization error is disregarded. Experimental results show the proposed scheme efficiently reduces the effects due to the variations of clock frequency and resistance. Further more the method has 1.04[pF] resolution and can be used as a touch key.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.301-304
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• 2011

This paper describes the possibility of a low-power, high-resolution fingerprint sensor chip. A modified capacitive detection circuit of charge sharing scheme is proposed, which reduces the static power dissipation and increases the voltage difference between a ridge and valley more than conventional circuit. The detection circuit is designed and simulated in 3.3V, 0.35${\mu}$m standard CMOS process, 40MHz condition. The result shows about 27% power dissipation reduction and 90% improvement of difference between a ridge and valley sensing voltage. The proposed circuit is more stable and effective than a typical circuit.