• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.593-594
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• 2008

In this article, process voltage temperature (PVT) compensated on-chip oscillator is implemented by using proportional to absolute temperature (PTAT) circuit and process compensator. Process compensator circuit based on current subtracter and PTAT circuit are proposed for compensation of oscillation frequency to cope with process variation and temperature variation. All circuit can operate in the range of $3.5{\sim}5\;V$ supply voltage. It can be applied to PVT insensitive low frequency clock reference generator.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1C
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• pp.29-38
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• 2011

The smaller diameter cone penetrometer has been widely used to estimate the characteristics of local area due to high vertical resolution. The half-bridge cirucits have been adopted to measure the mechnical strength of soil through the smaller diameter cone penetrometer due to the limitation of the areas for configuring the full-bridge circuit. The half-bridge circuit, however, is known as being easily affected to the temperature variation. The objective of this study suggests the temperature-compensated method in mini-cones. The diameter and length of the mini-cone is designed to 15mm and 56mm. The load cell of the mini-cone is extended about 54mm on the behind of the mini-cone to reflect the only temperature variation. The full-bridge circuit is installed to measure the temperature-compensated values in the mini-cone and the half-bridge circuit is also organized to compare the temperature compensated values with uncompensated values. The seasonal variation tests are performed to define the effect of temperature variation under summer and winter temperature condition. The densification tests are also carried out to investigate temperature effects during penetration. The measured mechanical resistances with temperature-compensated method show more reliable and reasonable values than those measured by thermal uncompensated system. This study suggests that the temperature-compensated method of the mini-cone may be a useful technique to obtain the more reliable resistances with minimizing the temperature effect.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.612-614
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• 2000

We propose a new curvature-compensated CMOS bandgap reference circuit that is achieved by varying a current ratio. The proposed circuit is shown to have small temperature coefficient that the output voltage variation is 0.4mV.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.10
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• pp.727-732
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• 2004

TCXO is one of the most important component in communication systems. We present a analytic method approach to design the Temperature Compensated Circuit. The conventional method for extracting the circuit parameters, which are for thermistor, Colpitts and frequency control circuit is the trial and error correction. In this paper, we analyse the temperature compensating circuit to extract TCXO circuit parameter. In order to show the validity of this paper, we have designed and implemented the 10MHz TCXO. The fabricated TCXO shows 1ppm frequency drift characteristic over the temperature range of -40℃∼85℃.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.728-735
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• 2016

A 70 MHz temperature-compensated on-chip CMOS relaxation oscillator for mobile display driver ICs is proposed to reduce frequency variations. The proposed oscillator compensates for frequency variation with respect to temperature by adjusting the bias currents to control the change in delay of comparators with temperature. A bandgap reference (BGR) is used to stabilize the bias currents with respect to temperature and supply voltages. Additional temperature compensation for the generated frequency is achieved by optimizing the resistance in the BGR after measuring the output frequency. In addition, a trimming circuit is implemented to reduce frequency variation with respect to process. The proposed relaxation oscillator is fabricated using 45 nm CMOS technology and occupies an active area of $0.15mm^2$. The measured frequency variations with respect to temperature and supply voltages are as follows: (i) ${\pm}0.23%$ for changes in temperature from -30 to $75^{\circ}C$, (ii) ${\pm}0.14%$ for changes in $V_{DD1}$ from 2.2 to 2.8 V, and (iii) ${\pm}1.88%$ for changes in $V_{DD2}$ from 1.05 to 1.15 V.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.78-83
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• 1996

A timing recovery circuit of 10 Gbit/s optical receiver is described. The circuit consists of a passive NRZ-to-PRZ circuit, a dielectric resonator filter (DRF) and a narrow band amplifier, which for the first time adopted a temperature compensation technique using the tempareature characteristics of DR. The experimental results showed an output clock phase variation of less than ${\pm}$6 degree over the operating temperature range form 0$^{\circ}C$ to 75$^{\circ}C$ and measured maximum rms jitters of less than 2 phs with the resonance detunings of up to ${\pm}$10 MHz. These experimental results show that the circuit is a suitable for 10 Gbit/s lightwave transmission system.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1495-1498
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• 2008

We proposed driving method with variable integration time for ambient light sensing. One operation period of the proposed driving method consists of several sub-integration periods with variable integration time which can enlarge dynamic range of ambient light sensing circuit. Temperature dependent characteristic of p-intrinsic-metal (p-i-m) diode can be compensated using the proposed driving method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.3
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• pp.223-228
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• 2010

In this paper, temperature compensation circuit for the X-band voltage controlled oscillator(VCO) is presented by using the temperature sensor with the OP-AMP circuit. The frequency drifting by the temperature could be compensated by applying the tuning voltage which include the linearly changing output voltage of the temperature sensor. As a result, the frequency variation is reduced to 6.6~4.4 MHzfrom the 71~73 MHz variation with the compensation circuit over -30~+$60^{\circ}C$ range, when VCO is operated in the frequency range of 9.95~10.05 GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1386-1391
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• 2000

In this paper, the method to linearize the non-linearity of diode and to compensate the characteristics change of diode with the temperature is studied. Square root circuit is used to linearize the non-linearity of diode about the input power, and two identical diodes and OP-Amps, which have variable reference, are used to compensate the characteristic change of diode with the temperature. As the result, designed diode power detector (with the square root circuit and temperature compensation circuit) can detect the output power linearly with the 0.23 $\pm$0.025V/dBm rate in the case the input power is greater than -6 dBm, and the designed circuit operates stably with no variation in the output data about the temperature change from the room temperature to 8$0^{\circ}C$.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.658-661
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• 2002

An analog multiplier-divider circuit that realized through the use of OTAs, which does not require external passive circuit elements and temperature compensated, is proposed in this paper. Since the scheme is realized in such a way that employs only OTA as a standard cell, the circuit is simple and can be easily constructed from commercially available IC. The circuit bandwidth is wide and close to the transistor f$\sub$T/. Simulation results that demonstrate the performances of the multiplier-divider circuit are included.