Tuwanut, Panwit
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Tuwanut, Panwit
Alternative Name
Tuwanut, P.
Tuwanuti, Panwit
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Email
panwit.tu@kmitl.ac.th
9 results
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Item type:Publication, A novel versatile modulator circuit(2005-12-01); ; In this paper, a novel versatile modulator that can function either as delta modulator, sigma-delta modulator, amplitude modulator and frequency modulator is proposed. The principle of the proposed scheme is based on schmitt-trigger circuit and composed of a few components: three OTAs, one capacitor and two resistors. The advantage of this circuit is that the clock (carrier) signal employed for modulation is inherent in the circuit. The modulating signal is therefore an external input requirement. Based on the compactness of the circuit, it is suitable for IC realization. The computer simulation demonstrates the results which agree well with the theoretical analysis. © 2005 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A simple circuit for sigma-delta /delta modulation(2005-12-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A simple and economic PWM and ΣΔ modulator circuit based on modified source-couple oscillator(2006-01-01); ; In this article, a simple and economic Pulse Width Modulator (PWM) and Sigma Delta Modulator (ΣΔ) circuit which is based on the modified CMOS source couple voltage-control oscillator is presented. The circuit can work either as PWM or ΣΔ modulator, depending on the condition of the two bias currents which are forced of the source couples. Namely, the circuit is a PWM when these two bias currents are out of phase. Otherwise, it is a ΣΔ modulator when both bias currents are identical. In addition, another feature of the proposed circuit is that the modulated signal can be either in voltage or current format. Moreover, the proposed circuit provides wide range of frequency operation because of few numbers of CMOS in the circuit. Furthermore, the circuit is very suitable for realization in integrated circuits (ICs) form and can be employed for optical communication application. The simulation results of the circuit are demonstrated and agreed well with theoretical anticipation. © 2006 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Triangular-to-cosine wave technique based on exponential approximation(2001-12-01); ; Maneechukate, ThongchaiA novel approach for triangular-to-cosine wave approximation is presented The cosine wave is generated by the method of squaring the triangular wave and the passing through the exponential amplifier circuits. This approach is based on the Taylor's series for sinusoidal function. The superior point of this method to the existing ones is the simple circuit realization and low distortion cosine wave output Besides that, the proposed circuit can generate the square, triangular wave. The section of square wave and triangular wave generating uses relaxation oscillator with feeding back in current mode that produce the triangular and square wave in the same circuit. Furthermore, the squaring and exponential amplifier circuit can be configured based on another principle such as translinear in current mode which can be developed to suit IC implementation. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, 7 Decade low frequency switched capacitor oscillator(2001-12-01); ; Maneechukate, ThongchaiIn this work a sine wave switched-capacitor (SC) oscillator based on feedback SC BPF oscillator is proposed. Advantage of this technique is high stability, constant amplitude at wide frequency range and suitable for amplitude control by output forced response technique. In addition, frequency tuning can be adjusted by clock control, which without effect to stability. The experimental results conforming the validity of the theory are also presented. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A novel versatile modulator circuit(2009-05-01); ; A novel versatile modulator that can operate either as a delta modulator, a sigma-delta modulator, an amplitude modulator or a frequency modulator is presented. The proposed circuit mainly composes of a few components: which are three OTAs, one capacitor and two resistors. Among these components, two OTAs and two resistor construct a Schmitt trigger network whereas the other OTA and a capacitor compose an integrator. The advantage of this circuit is that the clock (carrier) signal employed for modulation is inherent in the circuit. No external clock is needed, only the modulating signal is required for an input. With the compactness of the circuit, it is thus suitable for IC realization. The computer simulation based on CMOS technology demonstrates that the results agree well with the theoretical analysis. © 2008 Elsevier GmbH. All rights reserved. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Time quantization derivative PWM based one-bit DPCM(2004-12-01); ; ; Koseeyaporn, P.A new 1-bit DPCM (differential pulse code modulator) circuit based on the derivative PWM (pulse width modulation) signal is proposed. The main concept of the proposed technique is that the difference of the adjacent input sample resides in the duty cycle of the derivative PWM signal. Therefore, one-bit digital signal can be exploited from the derivative PWM waveform in which the quantization process is performed in time axis, not in conventional amplitude axis. The derivative PWM principled circuit, which is composed of 3 OTAs, 1 capacitor, and 2 resistors, provides the simplicity and compactness of the circuit's structure. In addition, the sampling operation is inherent in the derivative PWM circuit thus only some additional components are required for the mentioned transformation process. Implicitly, the proposed circuit is suitable for integrated circuit fabricating technology. The PSPICE simulation outputs of the proposed technique have demonstrated the expected results. Also, SNR analysis of the quantization process will be briefly discussed. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, New analytic solution of second-order oscillator using multi-time variables technique(2005-01-01); ; In this paper, a new analysis of sinusoidal oscillator amplitude controlled by forced response using the second order differential equation (ODE) is proposed. In general, the amplitude of the complete response is derived where forced response slope is normally assumed to be zero. The value of forced response only at initial time is thus employed to determine the amplitude. But if forced input is dynamic signal the amplitude of complete response gained by using such assumption is different from the experimental result. Thus, a new analysis of amplitude for a dynamic forced response is proposed in this paper. It is found that the forced response at any arbitrary time (not only at the initial time) is presented in a term of natural response magnitude. Magnitude of natural response is therefore directly controlled by forced response. To confirm the theoretical analysis, experimental results have been demonstrated and agreed well with the analysis results. © 2005 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A novel monostable multivibrator circuit(2005-01-01); ; This article represents a novel monostable multivibrator circuit in which width and height of the pulse output can be independent electronically adjusted. In addition, the pulse width of output is not restricted to be wider or narrower than that of input pulse as conventionally employed. Namely, there is no restriction on the width of input and output pulse, the circuit's implementation is thus more convenient. The proposed circuit is composed of three OTAs, two resistors and one capacitor, basically constructed a simple pulse generator (Schmitt-trigger circuit). Therewith the compactness of the circuit, It Is thus suitable to be fabricated for integrated circuit. The results of circuit simulation is accordance well with theoretical analysis.