Montree Siripruchyanun

Current controlled current conveyor transconductance amplifier (CCCCTA): a building block for analog signal processing

This article presents a basic current-mode building block for analog signal processing, namely current controlled current conveyor transconductance amplifier (CCCCTA). Its parasitic resistance at current input port can be controlled by an input bias current. It is very suitable to use in a current-mode signal processing, which is continually more popular than a voltage one. The proposed element is realized in a bipolar technology and is examined the performances through PSPICE simulations. They display usabilities of the new active element. The CCCCTA performs tuning over a wide current range. In addition, some examples as a current-mode universal biquad filter and a grounded inductance simulator are included. They occupy only single CCCCTA.

Realization of electronically tunable voltage-mode/current-mode quadrature sinusoidal oscillator using ZC-CG-CDBA

This paper presents a first of its kind canonic realization of active RC (ARC) sinusoidal oscillator with non-interactive/independent tuning laws, which simultaneously provides buffered quadrature voltage outputs and explicit quadrature current outputs. The proposed circuit is created using a new active building block, namely the Z-copy controlled-gain current differencing buffered amplifier (ZC-CG-CDBA). The circuit uses three resistors and two grounded capacitors, and provides independent/non-interactive control of the condition of oscillation (CO) and the frequency of oscillation (FO) by means of different resistors. Other advantageous features of the circuit are the inherent electronic tunability of the FO via controlling current gains of the active elements and the suitability to be employed as a low-frequency oscillator. A non-ideal analysis of the circuit is carried out and experimental results verifying the workability of the proposed circuit are included.

Resistorless dual-mode quadrature sinusoidal oscillator using a single active building block

This paper presents a new realization of resistorless mixed-mode (i.e. both voltage-mode and current-mode) quadrature sinusoidal oscillator using a new active building block (ABB) called the differential voltage current-controlled conveyor transconductance amplifier (DVCCCTA). The proposed oscillator circuit uses a single DVCCCTA, two grounded capacitors (GCs) and does not employ any external linear resistors. The tuning laws for the condition of oscillation (CO) and the frequency of oscillation (FO) are non-interactive; and controlled by separate bias currents. The circuit provides two explicit quadrature current outputs and two quadrature voltage outputs and thus can be classified as a mixed-mode quadrature oscillator. Another notable feature of the proposed circuit is that it can also be used as a biquadratic filter to realize low-pass and band-pass filtering functions simultaneously. Non-ideal analysis of the circuit is provided and PSpice simulation results have been included to verify the workability of the proposed circuit.

High-output-impedance current-mode multiphase sinusoidal oscillator employing current differencing transconductance amplifier-based allpass filters

This article presents a multiphase sinusoidal oscillator using current differencing transconductance amplifier (CDTA)-based allpass filters. The oscillation condition and oscillation frequency can be orthogonally controlled. The proposed circuit provides 2n – phase signals (n≥2) that are equally spaced in phase and of equal amplitude. The circuit requires one CDTA, two resistors and one capacitor for each phase and no additional current amplifier. Owing to high-output impedances, the proposed circuit enables easy cascading in current-mode configurations. The effects of the nonidealities of the CDTA-allpass sections were also studied. The results of PSpice simulations are presented, demonstrating their consistency with theoretical assumptions.

A synthesis of temperature insensitive/electronically controllable floating simulators based on DV-CCTAs

A circuit topology for synthesis of floating inductance, floating capacitance mulplier and floating frequency dependent negative resistance (FDNR) conversion depending on the external passive component selection is proposed in this paper. The proposed simulator employs 2 differential voltage current conveyor transconductance amplifiers (DV-CCTAs) and only 3 grounded passive elements without component matching requirements. The simulated component values can be adjusted electronically by input bias currents of the DV-CCTAs and are temperature-insensitive. The application example as a bandpass filter is included. The simulation results using PSPICE are given for the introduced floating simulator to verify the theory and to exhibit the performances of the circuit.

Practical implementation of CCTA based on commercial CCII and OTA

This article presents a basic current-mode building block for analog signal processing, namely current conveyor transconductance amplifier (CCTA) using the commercially available ICs. The performances are examined through PSPICE simulations and experiment, displaying usabilities of the new active element. The description includes some examples as a voltage-mode universal biquad filter, a grounded inductance, a current-mode multiplier and oscillator. They occupy only a single CCTA.

A simple pulse width modulator using current conveyor

A simple pulse width modulator (PWM) is proposed. The circuit principle is based on a relaxation oscillator with a second generation current conveyor (CCII). The proposed scheme is simpler than the existing PWM methods and the duty factor linearly depends on the modulating signal. Another advantage is that the circuit is suitable for IC implementation. The simulation and experimental results are given. They show good agreement with the theoretical analysis.

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.

An electronically controlled current-mode triangular/square wave generator employing MO-CCCCTAs

A new current-mode triangular/square wave generator based on MO-CCCCTAs (Multiple output current controlled current conveyor transconductance amplifiers) is presented in this paper. The circuit description is very simple, its construction consists of 2 MO-CCCCTAs and 1 grounded capacitor without any external resistor. The output frequency and amplitude can be electronically/independently tuned via corresponding input bias currents. With mentioned features, it is very suitable to realize in a monolithic chip. The PSpice simulation results are depicted, and agree well with the theoretical anticipation. The maximum power consumption is approximately 1.62mW at ±1.5V power supply.

A simple current-mode Schmitt trigger employing only single MO-CTTA

A new current-mode Schmitt trigger based on MOCTTA (Multiple output current through transconductance amplifier) is presented in this article. The circuit description is very simple, its construction consists of only single MO-CTTA. The hysteresis and amplitude of the output current can be tuned independently/electronically. With mentioned features, it is very suitable to realize in a monolithic chip. The PSPICE simulation and experimental results are depicted, and agree well with the theoretical anticipation. The maximum power consumption is approximately 249mW at ±5V supply voltages.