Single Operational Current Amplifier Based Sinusoidal Oscillators

This paper presents important missing sinusoidal oscillators. There are numerous sinusoidal oscillators versions based on the three fundamental amplifiers namely the operational amplifier (OpAmp), the operational transconductance amplifier (OTA), and the operational transresistance amplifier (OTRA) but their counterparts based on the fourth type that is the operational current amplifier (OCA) are to be reported. Traditional applications use voltage-mode oscillators, however, several modern applications such as electrical impedance spectroscopy (EIS) require current-mode oscillators. In the literature, many current-mode oscillators have been proposed; however, they use active building blocks which operate in both voltage and current modes. In this paper, we propose two novel oscillators using the pure current-mode active element namely the OCA. Simulation results obtained from a standard 180nm CMOS process are provided. It is shown that the proposed oscillators consume approximately 120µW while working in the MHz range. Also, experimental results using prototypes implemented using commercially available ICs show the validity of the proposed designs.