Supawat Lawanwisut

High output-impedance current-mode third-order quadrature oscillator based on CCCCTAs

This article presents a 3rd order current-mode quadrature oscillator using current controlled current conveyor transconductance amplifiers (CCCCTAs) as active elements. The proposed circuit is realized from a non-inverting lossless integrator and an inverting second-order lowpass filter. The oscillation condition and oscillation frequency can be electronically/orthogonally controlled via input bias currents. The circuit description is very simple, consisting of merely 2 CCCCTAs and 2 grounded capacitors. Without any external resistors and using only grounded elements, the proposed circuit is then suitable for IC architecture. Due to high-output impedances, the proposed circuit is enable easy cascading in current-mode. The PSPICE simulation results are depicted, and the given results agree well with the theoretical anticipation. The power consumption is approximately 2.43mW at ±3V supply voltages.

A four-inputs single-output current-mode biquad filter using a minimum number of active and passive components

This article presents a four-inputs single output biquadratic filter performing completely standard functions: low-pass, high-pass, band-pass, band-reject and all-pass functions, based on single current controlled current follower transconductance amplifier (CCCFTA). The features of the circuit are that; the quality factor and natural frequency can be tuned electronically via the input bias current; the circuit description is very simple, consisting of merely 1 CCCFTA and 2 grounded capacitors; the filter does not require inverting-type input current signal. Additionally, each function response can be selected by suitably selecting input signals with digital method. Using only single active element and grounded capacitors, the proposed circuit is very suitable to further develop into an integrated circuit. The PSPICE simulation results are depicted. The given results agree well with the theoretical anticipation.

An active-only high-output impedance current-mode quadrature oscillator using CCCCTA based-lossless differentiators

This article presents a high-output impedance current-mode quadrature sinusoidal oscillator, providing sinusoidal signals, which differ of 90° in phase. The features of the proposed circuit are that; oscillation frequency can be electronically controlled; it can provide the quadrature signal, which is free from the preset of oscillation condition. In addition, since the proposed circuit comprises only active elements, which are 2 CCCCTAs and 2 operational amplifiers, it is very suitable to further develop into an integrated circuit. The PSPICE simulation results are depicted.

An electronically controllable active-only current-mode floating inductance simulator

This article reviews a circuit which is active-only floating positive inductance simulator. The floating inductance simulator comprises merely one current controlled current conveyor transconductance amplifier (CCCCTA) and an internally frequency compensated operational amplifier. The simulated inductance value can be controlled electronically by adjusting bias current of the CCCCTA. The circuit performances are depicted through PSpice simulation, they show good agreement to theoretical anticipation. An application as a resonant circuit is included to confirm the usability of proposed circuit.

A temperature-insensitive simple current-mode squarer employing only multiple-output CCTAs

This article presents a new current-mode squarer based on MO-CCTA (Multiple output current conveyor transconductance amplifier). The circuit description is very simple, its construction consists of merely 2 MO-CCTAs. Without external passive elements, the proposed circuit is then suitable for IC architecture. The PSPICE simulation and experimental results are depicted, and agree well with the theoretical anticipation. From simulation results, the maximum power consumption is approximately 550µW at ±2V power supply voltages.

An active-only electronically controllable current-mode multifunction filter using CCCFTAs

This article presents a current-mode multifunction filter performing completely standard function: low-pass, highpass, band-pass, band-reject and all-pass functions. The features of the circuit are that: the quality factor and pole frequency can be tuned by DC controlled bias current: the circuit description is very simple, it comprises only active elements, which are 2 current controlled current follower transconductance amplifiers (CCCFTAs) and 2 operational amplifiers (OAs). The proposed circuit is very suitable to further develop into an integrated circuit architecture. The PSpice simulation results are shown. The total power consumption is approximately 23.1mW at ±5V supply voltages. The given results agree well with the theoretical anticipation.

A synthesis of low component count for current-mode PID, PI and PD controllers employing single CCTA and Grounded elements

This paper presents a synthesis of current-mode PI, PD and PID controllers employing current conveyor transconductance amplifier (CCTA). The features of these controllers are that: the output parameters can be an electronically controlled by adjusting corresponding bias currents, circuit description of the PID controller is simply formulated, it consists of only one CCTA cooperating with 2 grounded resistors and 2 grounded capacitors, PI and PD controllers are composed of single CCTA, 2 grounded resistors, 2 grounded capacitors and 3 grounded resistors, a grounded capacitor, respectively. This proposed circuit is very suitable to develop into an integrated circuit. The given results of the PSpice simulation agree well with the theoretical anticipation. The maximum power consumption in a closed-loop control system obtained from the PID controller and current-mode low-pass filter are approximately 0.393mW and PI and PD controllers are 0.379mW and 0.367mW, respectively at ±1.5V supply voltages.

An electronically controllable dual-mode universal filter using DO-CCCDBAs

This article presents a dual-mode (voltage-mode and current-mode) universal biquadratic filter performing completely standard functions: low-pass, high-pass, band-pass, band-reject and all-pass functions, based on Dual Output Current Controlled Current Differencing Buffered Amplifiers (DO-CCCDBAs). The features of the circuit are that: the bandwidth and pole frequency can be tuned electronically via the input bias currents: the circuit description is very simple, consisting of merely 2 DO-CCCDBAs and 2 capacitors: the circuit can provide either the voltage-mode or current-mode filter without changing circuit topology. Additionally, each function response can be selected by suitably selecting input signals in digital method. Without any external resistor and simple configuration, the proposed circuit is very suitable to further develop into an integrated circuit. The PSPICE simulation results are depicted, the given results agree well with the theoretical anticipation. The maximum power consumption is approximately 1.81mW at ±1.5V supply voltages.