• 전자공학회논문지
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• 제54권1호
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• pp.26-32
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• 2017

본 논문에서는 설계 요구가 높고, 전력 소모가 높은 opamp를 이용하는 기존의 능동형 적분기를, 수동형 적분기로 대체하여 고속의 저전력, 고해상도 특성을 갖는 incremental delta-sigma ADC를 소개한다. 능동형 적분기에서 수동형 적분기로의 변환을 위해, 기존의 능동형 적분기의 특성을 분석하였다. 이를 바탕으로 opamp의 설계 요구를 낮추고, 더 나아가 opamp를 사용하지 않는 저전력의 수동형 적분기를 제안하였다. 65nm 공정을 이용하여 수동형 적분기로 구성된 1차 single-bit incremental delta-sigma ADC를 설계하였다. Transistor-level 시뮬레이션 결과, 이는 supply 전압이 1.2V인 상황에서 modulator만 0.6uW, digital filter를 포함한 ADC 전체에서 6.25uW를 소모하며 BW 22KHz, SNDR 71dB, dynamic range 74.6dB을 달성하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.158.4-158
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• 2001

This paper presents a novel circuit configuration for realizing the continuous-time active-only voltage-mode integrator. The proposed integrator consists only of internally compensated type operational amplifier (OA) and operational transconductance amplifiers (OTAs). Since no external passive elements are required, the integrator is suitable for integrated circuit implementation in either bipolar or CMOS technologies. Moreover, the integrator gain can be electronically tuned by adjusting the bias currents of the OTAs. The characteristics of the proposed integrator and the effectiveness of the design procedure in realizing various analog transfer functions have been examined by PSPICE simulation.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -2
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• pp.747-750
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• 2002

A circuit building block for realizing a continuous-time active-only current-mode integrator is presented. The proposed integrator is composed only of internally compensated type operational amplifier (OA) and operational transconductance amplifiers (OTAs). The integrator is suitable for integrated circuit implementation in either bipolar or CMOS technologies, since it does not require any external passive elements. Moreover, the integrator gain can be tuned through the transconductance gains of the OTAs. Some application examples in the realization of current-mode network functions using the proposed current-mode integrator as an active element are also given.

• Journal of information and communication convergence engineering
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• 제8권5호
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• pp.566-569
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• 2010

This paper describes the sinusoidal, pulse, triangular oscillator using second generation current conveyor. To obtain the sinusoidal waveform the circuit blocks are constructed by using all pass filter and integrator. The pulse and the triangular waveforms are obtained from the output of sinusoidal oscillator. The peak-to-peak voltages of sinusoidal and triangular waveforms can be easily controlled by the dc offset voltage. Also the output frequency of the oscillator can be controlled by varying passive elements. The designed circuit is verified by HSPICE simulation.

• 센서학회지
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• 제6권2호
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• pp.115-122
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• 1997

집적된 수동소자의 변동에 의한 RC 시상수 변동을 보정하는 on-chip 자동 보정(tuning)회로를 제안된 적분레벨 근사화 기법을 이용하여 설계하였다. 이 방법은 기존의 이중경사 보정회로가 갖는 결점인 미발생 코드 존재와 오류코드 발생을 해결할 수 있으며, 보정코드가 정상적인 동작을 할 때는 고정되기 때문에 집적회로에서 처리되는 신호의 변조를 유발하지 않는다. 이 보정회로는 적분기와 간단한 A/D 변환기 및 디지탈 제어 회로로 구성되며, 집적회로내의 모든 커패시터는 커패시터 열로 대체된 후 설정된 RC 시상수를 유지하도록 보정회로에 의해서 프로그램 된다. 설계된 자동 보정회로에 의하여 ${\pm}50%$의 시상수 변동율을 갖는 집적 시스템의 RC 시상수 오차범위는 4비트 보정로드의 경우 $-9.74{\sim}+9.69%$로 측정되었다.

• 대한전기학회논문지
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• 제43권7호
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• pp.1206-1213
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• 1994

This paper presents the operation principle and design rule of the Rogowski coil which can measure the transient current and describes the calibration and application experimental results for performance evaluation. It is obtained that the response curves of the Robowski coil with the turns of 300 and the passive integrator to sinusoidal input give a good linearity up to the frequency of 500 [kHz] and the current measurement system gaving the Rogowski coil is the frequency bandwidth of 40 [Hz]~700 [kHz]. As an application experiment for the fabricated modeling power transmission line, the impulse current, which limitates the direct lightning return stroke to overhead ground wire, is measured by the Rogowski coil and its fast Fourier transformation is carried out. The equivalent circuit of the Rogowski coil considering the stray capacitances is proposed, and the theoretical analysis is in good agreement with the measurement results. Also, it is found that for high frequency domain the stray capacitance such as a distributed capacitance to the shield and the capacitance between windings of coil should be considered in designing the Rogowski coils since the resonance originates from the stray capacitance and the self-inductance of the Rogowski coil.

• Journal of Power Electronics
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• 제11권3호
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• pp.311-318
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• 2011

LCL filters installed at converter outputs offer a higher harmonic attenuation than L filters. However, as a three order resonant circuit, it is difficult to stabilize and has a risk of oscillating with the power grid. Therefore, careful design is required to damp LCL resonance. Compared to a passive damping method, an active damping method is a more attractive solution for this problem, since it avoids extra power losses. In this paper, the damping capabilities of capacitor current, capacitor voltage, and grid-side current feedback methods, are analyzed under the discrete-time state-space model. Theoretical analysis shows that the grid-side current feedback method is more suitable for use in active power filters, because it can damp LCL resonance more effectively than the other two methods when the ratio of the resonance and the control frequency is between 0.225 and 0.325. Furthermore, since there is no need for extra sensors for additional states measurements, this method provides a cost-efficient solution. To support the theoretical analysis, the proposed method is tested on a 7-kVA single-phase shunt active power filter.