TABLE OF CONTENTS Current conveyors can be also successfully used in the design of oscillators. In fact, they have shown to provide wider bandwidth and a best accuracy with respect to the traditional op-amps. Moreover, they do not present a serious disadvantage of op-amp based oscillators. In fact, it has been proved [34] that the limitation of the finite GBW product affects the frequency oscillation as well as the oscillation condition. For this reason, CCII-based oscillators have been proposed in the literature since more than 20 years ago [35], [36], [37].
Anyway, in signal processing a wide number of voltage-mode solutions have been developed. That's why it is not unusual to find transformation methods that allow to obtain a current-mode solution from its voltage-mode counterpart [38], [39], [40], [41]. An example of this approach is constituted by the design of a Wien oscillator, whose solution using a VCVS as amplifier block in a Wien bridge is shown in figure 5.49 [41].
The design equations for this oscillator are the following:
being K the VCVS voltage gain.
We can consider R 1 as a part of the active block; in this case the VCVS is replaced by a VCCS, whose gain is K/R 1. Using different solutions for the VCCS implementation, different expression of the gain have to be considered.
CCIIs can be employed in the design of any kind of active block, then other CCII-based...
