Husain Abdullah Al-Zaher

Current-mode sinusoidal oscillators using single FTFN

New current-mode sinusoidal oscillator circuits are presented. The proposed circuits use single four-terminal floating nullor and, at most, eight passive elements. Two of the oscillator circuits use grounded capacitors and enjoy the independent grounded-element control of the frequency of oscillation and the condition of oscillation. Experimental results are included.

Active-only sinusoidal oscillator

A new active-only sinusoidal oscillator is proposed. The oscillator uses only two operational amplifiers and three operational transconductance amplifiers. Without using any external passive elements, voltage (or current) control of the frequency and condition of oscillation can be achieved by adjusting the bias currents of the OTAs. The proposed circuit enjoys low sensitivities.

Simulation of active-only floating inductance

A simple circuit for realizing active-only lossless floating inductor is presented. The circuit uses only two active elements ; a dual output operational transconductance amplifier and an internally compensated operational amplifier. The circuit is suitable for monolithic implementation in either bipolar or MOS technologies. Simulation results of a high-order lowpass filter using two simulated lossless floating inductors are included.

Current-mode quadrature sinusoidal oscillators using two FTFNs

New current-mode quadrature sinusoidal oscillator circuits are obtained from a voltage-mode two-operational-amplifiers based quadrature oscillator circuit by replacing the operational amplifiers by four-terminal floating-nullors (FTFNs). The properties of the resulting oscillators are discussed and the theory is supported by SPICE simulation.

Novel grounded-capacitor active biquads using FiTFNs

Abstract Novel current-, voltage- and mixed-mode grounded-capacitor active biquad circuit designs, using the five-terminal floating nullors, are presented. The proposed circuits enjoy low active and passive sensitivities and independent grounded-element control of the parameters ω 0 and ω 0 Q 0 .

Grounded-Capacitor Current-Mode Sinusoidal Oscillators with Single-Element Controlled Amplitude and Phase Using Two FTFNs.

A new current-mode sinusoidal oscillator circuit is presented of which the frequency and phase are single-element controlled. The circuit has two output currents. The frequency of oscillation is controlled by using a grounded resistor without disturbing the condition of oscillation. The phase difference between the two output currents can be controlled using a grounded passive element (resistor or capacitor or inductor) without disturbing the frequency of oscillation. The theoretical results are confirmed using SPICE simulation. Übersicht En neuer Sinusoszillator wird vorgestellt, dessen Amplitude und Phase jeweils mit einem einzigen Element eingestellt werden können. Der Schaltkreis hat zwei Stromquellen-Ausgänge. Die Oszillatorfrequenz wird mit einem einseitig geerdeten Widerstand eingestellt, ohne daß dabei die Schwingbedingung verletzt würde. Die Phasendifferenz zwischen den beiden Ausgangsströmen kann mit einem passiven, einseitig geerdeten Element (Widerstand oder Kapazität oder Induktivität) ohne Störung der Schwingfrequenz gesteuert werden. Die theoretischen Ergebnisse werden duch SPICE-Simulationen bestätigt. Für die Dokumentation Oszillator / Nullor / integrierte Analogschaltung

New grounded-capacitor sinusoidal oscillators using the current-feedback-amplifier pole

New current-feedback-operational amplifier (CFOA)-pole-based sinusoidal oscillator circuits are presented. Each circuit uses two CFOAs, two (or three) grounded capacitors and/or resistors. Experimental results are included.

Nonlinear performance of the mixed translinear loop

The nonlinear behaviour of the mixed translinear loop is analysed. Closed-form expressions are obtained for the harmonic and intermodulation components resulting from a multisinusoidal input signal. These expressions can be used to predict the limiting values of the input current for a prespecified tolerable distortion percentage.

A novel single-capacitor single-operational-amplifier sinusoidal oscillator

The well known operational amplifier based Schmitt-trigger square wave generator is shown to behave as a sinusoidal oscillator at relatively high frequencies. This is attributed to the widely ignored frequency-dependence characteristic of the differential gain of the operational amplifier. Experimental results are in excellent agreement with theoretical predictions. >

Versatile Active Biquad Using FTFNs

A universal active biquad using the four-terminal floating nullors (FTFNs) is presented. The propsed circuit uses two FTFNs, three capacitors and two resistors. The proposed circuit has three input voltages and can simultaneously provide a high-impedance output current and/or an output voltage. Without changing the circuit topology, the output voltage can realise lowpass, highpass, bandpass, notch and allpass transfer functions and the output current can realise bandpass and highpass transfer functions. The proposed circuit enjoys low active and passive sensitivities and independent control of the parameters ωo and ω0/Q0.