Design of Z-copy controlled-gain voltage differencing current conveyor based adjustable functional generator

This paper deals with a very simple functional generator employing single multi-terminal advanced active device, so-called z-copy controlled gain voltage differencing current conveyor (ZC-CG-VDCC). This active element offers various inter-terminal relations and interesting possibilities of multi-parameter electronic control, which are utilized to control resulting application (triangular and square wave generator). Simple pulse width modulator (PWM) based on two ZC-CG-VDCCs is a further application example of presented generator. Verification of expected behavior was performed by simulation based on CMOS model of the ZC-CG-VDCC and also by lab measurement. DOI: http://dx.doi.org/10.5755/j01.eee.21.5.13322

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Simple Resistor-less Generator Utilizing Z-copy Controlled Gain Voltage Differencing Current Conveyor for PWM Generation

This contribution deals with simple and adjustable triangular and square wave generator employing diamond transistor, two voltage controllable amplifiers, one resistor and grounded capacitor. Main aim is the exploration of adjustable features of a real circuit compared to ideal estimations. Detailed analysis and experimental tests proved that nearly ideal estimations give inaccurate results. We performed refinements corrections where existence of saturation in voltage controllable amplifier, that tunes frequency, was considered in calculations. Results proved possible controllability in discussed solution but reveal also high dependence of features (repeating frequency and produced amplitudes) on features of particular active element (mainly voltage controllable amplifier) in the design because each active element has little bit different output saturation levels (dependent on fabrication tolerance, etc.).

Practical aspects of operation of simple triangular and square wave generator employing diamond transistor and controllable amplifiers

This paper deals with idea of an electronically reconfigurable integrator utilized in nonlinear application of functional generator and study of its features in this circuit The integrator can be electronically readjusted to lossy and lossless type as well as this integrator also offers electronic tuning of time constant Possibility of simple electronic reconfiguration provides generation of square wave and selection to generate triangular or exponential (relaxation) output waveforms in node of working capacitor Intentions of synthesis and design were confirmed by PSpice simulations

Special electronically reconfigurable lossy/lossless integrator in application of functional generator

This paper introduces novel solution of triangular and square wave generator employing circuitry of interesting and unusual Schmitt trigger and specially prepared modification of lossless integrator connected in low-impedance input terminal of the comparator that allows linear charging of capacity and therefore also triangular wave generation that is not available in standard cases of applications (only relaxation generator available – exponential and square wave). Design and supposed operation of the circuit was verified not only theoretically but also experimentally with CMOS implementation of employed active elements available in form of IC device fabricated in 0.35 μm I3T ON Semiconductor process. Achieved result confirmed studied features of triangular wave generation and linear electronic tunability of its frequency between 23 and 151 kHz.

Special Type of Current Conveyor-Based Schmitt Trigger in Novel Design of Triangular Waveform Generator

A novel relaxation oscillator based on integrating the diode-switched currents and Schmitt trigger is presented. It is derived from a known circuit with operational amplifiers where these active elements were replaced by current conveyors. The circuit employs only grounded resistances and capacitance and is suitable for high frequency square and triangular signal generation. Its frequency can be linearly and accurately controlled by voltage that is applied to a high-impedance input. Computer simulation with a model of a manufactured conveyor prototype verifies theoretic assumptions.

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Martin Janecek

Papers

Voltage-Controlled Square/Triangular Wave Generator with Current Conveyors and Switching Diodes