Electronically Tunable Current-mode Multiphase Sinusoidal Oscillator Employing CCCDTA-based Allpass Filters with Only Grounded Passive Elements

This study describes the design of a multiphase sinusoidal oscillator (MSO) using CCCDTA-based allpass filters with grounded capacitors. The oscillation condition and oscillation frequency can be electronically/orthogonally controlled. The proposed MSO provides 2n (n>2) phase signals that are equally spaced in phase and of equal amplitude. The circuit requires one CCCDTA, one electronic resistor and one grounded capacitor per phase and no additional current amplifier and floating elements. High output impedances of the configuration enable the circuit to be cascaded to the current-mode circuit without additional current buffers. The effects of the non-idealities of the CCCDTA-allpass sections were also studied. The results of PSPICE simulations using CMOS CCCDTA are presented, demonstrating their consistency with theoretical assumptions

High Input Impedance Voltage-Mode Biquad Filter Using VD-DIBAs

This paper deals with a single-input multiple-output biquadratic filter providing three functions (low-pass, high-pass and band-pass) based on voltage differencing differential input buffered amplifier (VD-DIBA). The quality factor and pole frequency can be electronically tuned via the bias current. The proposed circuit uses two VD-DIBAs and two grounded capacitors without any external resistors, which is suitable to further develop into an integrated circuit. Moreover, the circuit possesses high input impedance, providing easy voltage-mode cascading. It is shown that the filter structure can be easily extended to multi-input filter without any additional components, providing also all-pass and band-reject properties. The PSPICE simulation and experimental results are included, verifying the key characteristics of the proposed filter. The given results agree well with the theoretical presumptions

A Simple Current-Mode Quadrature Oscillator Using Single CDTA

This article presents a simple current-mode quadrature oscillator using a single Current Differencing Transconductance Amplifier (CDTA) as the active element. The oscillation condition and oscillation frequency can be electronically controlled. The circuit structure is very simple, consisting of merely one CDTA, one resistor and two capacitors. The proposed circuit is suitable for IC architecture. The PSpice simulation and experimental results are shown, and the results agree well with the theoretical assumptions

Three-Input Single-Output Electronically Controllable Dual-Mode Universal Biquad Filter Using DO-CCCIIs

This article presents a dual-mode (voltage-mode and current-mode) universal biquadratic filter performing completely standard functions: lowpass, highpass, bandpass, band-reject, and allpass functions, based on plus-type dual-output second-generation, current controlled, current conveyor (DO-CCCII+). The features of the circuit are that the bandwidth and natural frequency can be tuned electronically via the input bias currents: the circuit description is very simple, consisting of merely 2 DO-CCCIIs 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 with digital method. Without any external resistors, 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 1.81 mW at ±1.5 V supply voltages

Realization of electronically controllable first-order current-mode allpass filter using CCCHs and its application

This article presents a resistorless current-mode first-order slip ass filter based on second generation current controlled current conveyors (CCCHs). The features of the circuit are that: the pole frequency can be electronically controlled via the input bias current: the circuit description is very simple, consisting of 2 CCCHs and single grounded capacitor, without any external resistors and component matching requirements. Consequently, the proposed circuit is very appropriate to further develop into an integrated circuit. Low input and high output impedances of the proposed configuration enable the circuit to be cascaded in current-mode without additional current buffers. The PSpice simulation results are depicted. The given results agree well with the theoretical anticipation. The application example as a current-mode quadrature oscillator is included

Design of current-mode sinusoidal quadrature oscillator using CCCHs

This paper presents the design of current-mode quadrature oscillator using second generation current controlled current conveyors (CCCIIs) as active element. The oscillator has high output impedance, electronic and independent control on oscillation condition and on oscillation frequency. It consists of 3 CCCIIs, two grounded capacitors and one electronic resistor. The proposed circuit is suitable for integrated circuit (IC) architecture. PSpice simulation result is included to demonstrate the practicality of the oscillator circuit

New Resistorless Current-mode Quadratur Oscillators Using 2 CCCDTAs and Grounded Capacitors

The current-mode quadrature oscillators using 2 current controlled current differencing transconductance amplifiers (CCCDTAs) and 2 grounded capacitors are presented. The proposed oscillators can provide 2 sinusoidal output currents with 90º phase difference. The oscillation condition and oscillation frequency can be electronically/independently controlled by adjusting the bias current of the CCCDTA. High output impedances of the configuration enable the circuit to be cascaded without additional current buffers. The use of only grounded capacitors is ideal for integration. The PSpice simulation results are depicted. The given results agree well with the theoretical anticipation

MISO Current-mode Biquad Filter with Independent Control of Pole Frequency and Quality Factor

This article presents a three-inputs single-output biquadratic filter performing completely standard functions: low-pass, high-pass, band-pass, band-reject and all-pass functions, based on current controlled current conveyor transconductance amplifier (CCCCTA). The quality factor and pole frequency can be electronically/independently tuned via the input bias current. The proposed circuit uses 2 CCCCTAs and 2 grounded capacitors without external any resistors which is very suitable to further develop into an integrated circuit. The filter does not require double input current signal. Each function response can be selected by suitably selecting input signals with digital method. Moreover, the circuit possesses high output impedance which would be an ideal choice for current-mode cascading. The PSPICE simulation results are included to verify the workability of the proposed filter. The given results agree well with the theoretical anticipation

New Gain Controllable Resistor-less Current-mode First Order Allpass Filter and its Application

New first order allpass filter (APF) in current mode, constructed from 2 CCCCTAs and grounded capacitor, is presented. The current gain and phase shift can be electronically /orthogonally controlled. Low input and high output impedances are achieved which make the circuit to be easily cascaded to the current-mode circuit without additional current buffers. The operation of the proposed filter has been verified through simulation results which confirm the theoretical analysis. The application example as current-mode quadrature oscillator with non-interactive current control for both of oscillation condition and oscillation frequency is included to show the usability of the proposed filter

High Input Impedance Voltage-Mode Biquad Filter Using VD-DIBAs

This paper deals with a single-input multiple-output biquadratic filter providing three functions (low-pass, high-pass and band-pass) based on voltage differencing differential input buffered amplifier (VD-DIBA). The quality factor and pole frequency can be electronically tuned via the bias current. The proposed circuit uses two VD-DIBAs and two grounded capacitors without any external resistors, which is suitable to further develop into an integrated circuit. Moreover, the circuit possesses high input impedance, providing easy voltage-mode cascading. It is shown that the filter structure can be easily extended to multi-input filter without any additional components, providing also all-pass and band-reject properties. The PSPICE simulation and experimental results are included, verifying the key characteristics of the proposed filter. The given results agree well with the theoretical presumptions