The Implementation of Single VCII-Based RC Sinusoidal Oscillators: 28 Novel Configurations

This work presents 28 schemes of RC oscillators that make use of a single second-generation voltage conveyor (VCII). Since the active elements are the only source of biasing current, these schemes represent a valid solution when energy-efficient performances are required. The proposed circuits enjoy all the benefits of the current-mode approach. Moreover, by employing a VCII, there is no need of an additional buffer for the voltage output readout, helping to keep system power consumption low. All the proposed configurations use only three resistors and two capacitors, that is, a lower number of components with respect to operational amplifier (OA) RC oscillators. This also reduces the power dissipation on resistors due to the Joule effect. A comprehensive theoretical analysis is provided to determine the theoretical oscillation condition (OC) and frequency, and the schemes are grouped based on this. Experimental tests using both simulations and measurements with the commercial AD844 as a VCII are performed to validate the theory. In particular, among the 28 schemes, 16 proved to work as per theory developed considering an ideal VCII, and sample experimental measurements are reported for such schemes. On the other hand, the other 12 schemes are found to not work with the AD844 as a VCII due to its parasitic elements, but they proved to work when computer simulated with an ideal VCII confirming the correctness of the theoretical treatment. An application example as sensor interface is finally proposed.