Linearly tunable Wien bridge oscillator realised with operational transconductance amplifiers

摘要

Starting from the classic Wien bridge oscillator (WBO), a new operational transconductance amplifier (OTA)-based sinusoidal oscillator configuration is evolved which provides linear control of oscillation frequency through an external current signal: a major advantage over op-amp-based WBOs. In contrast to a recent oscillator by Abuelma'atti and Humood which employs five OTAs, the present circuit employs only three OTAs (along with two capacitors and one resistor), yet still provides the essential properties available in Abuelma'atti and Humood's proposition.