Electronically controllable third-order quadrature sinusoidal oscillator employing CMOS-OTAs

Abstract

This paper describes a voltage mode third-order quadrature sinusoidal oscillator (TOQSO) based on operational transconductance amplifiers (OTAs). The proposed configuration uses three OTAs and three grounded capacitors. Outputs of two voltage mode sinusoids with 90° phase difference are found in the proposed oscillator circuit. The condition of oscillation and frequency of oscillation are independently electronically controllable by separate transconductances of the OTAs. The performance of TOQSO is tested by SPICE (version 16.5) simulation using TSMC 0.18 µm technology parameters and experimental results employing CA3080 type IC OTAs have been presented to confirm the workability of the proposed new configuration.