Tuntrakool, Sunti

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Tuntrakool, Sunti
Alternative Name
Tuntrakool, S.
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Email
sunti.tu@kmitl.ac.th

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    A new quadrature sinusoidal oscillator for telecommunication system using VDDDAs
    (2016-03-22)
    Chaichana, Amornchai
    ;
    Jaikla, Winai
    ;
    Suwanjan, Peerawut
    ;
    Tuntrakool, Sunti
    A CMOS voltage differencing differential difference amplifiers (VDDDAs) based voltage-mode quadrature sinusoidal oscillator is proposed. The proposed oscillator is based on the two integrator loop configuration with amplifier wherein the frequency of oscillation (FO) is tuned by the time constant of two integrator and the condition of oscillation (CO) is tuned by gain of amplifier. It is constructed from two VDDDAs, two resistors, and two grounded capacitors. With this structure, it is attractive to develop in monolithic chip. The tuning of frequency of oscillation can be electronically done without affecting the condition of oscillation. Also, the condition of oscillation can be adjusted by external resistor without affecting to frequency of oscillation. The simulation results have been demonstrated and discussed using parameters of 0.18um TSMC CMOS technology and +0.9V power supply voltages.
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    Item type:Publication,
    High input impedance voltage-mode universal filter and its modification as quadrature oscillator using VDDDAs
    (2017-05-01)
    Tuntrakool, Sunti
    ;
    Kumngern, Montree
    ;
    Sotner, Roman
    ;
    Herencsar, Norbert
    ;
    Suwanjan, Peerawut
    The second order universal voltage-mode filter using voltage differencing differential difference amplifiers (VDDDAs) has been proposed. It has high input impedance voltage-mode biquad filter with orthogonal tune of natural frequency and quality factor. The proposed filter simultaneously provides five filter responses: low-pass (LP), high-pass (HP), band-reject (BR), all-pass (AP) and band-pass (BP) in the same circuit topology. The natural frequency and quality factor can be tuned electronically and orthogonally dc bias current. The output impedance at output nodes HP, AP and BR has low impedance which can connect to other circuit without the use of voltage buffers. The proposed filter consists of three VDDDAs, one grounded resistor and two grounded capacitors. This makes the proposed filter suitable for integrated circuit development. With slightly modifying the proposed filter, the voltage-mode qudrature sinusoidal oscillator with low output impedance and independent control of condition of oscillation (CO) and frequency of oscillation (FO) has been achieved. The results shown in this paper are from PSPICE simulation and experiment to validate the proposed circuits.