Autors: Pandiev, I. M. Title: Analysis and design of quartz crystal oscillators employing dual four-terminal current-feedback operational amplifiers Keywords: analog circuits, oscillators, crystal resonators, current co Abstract: In this paper four new sinusoidal crystal oscillators, using dual four-terminal current-feedback amplifiers (CFAs) are proposed. The four-terminal CFAs are special type of monolithic operational amplifiers and can be represented as a cascade structure of positive second-generation current conveyor (CCII+) and an additional vol¬tage follower (buffer). The presented crystal oscillators are the results of a systematic circuit synthesis and can comparatively easily be derived from the classical Butler structure based on the Colpitts oscillator. The proposed circuits provide the following advantages: (1) the insignificant influence of the load over the parameters of the oscillators, (2) ability for independent fine tuning of oscillation frequency and oscillation condition by grounded capacitor (or inductor) and resistor, (3) low output impedance, (4) very good frequency stability. References Issue
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