Voltage differencing gain amplifier-based sinusoidal quadrature oscillator using only two grounded capacitors

Background: This article describes the circuit construction of the sinusoidal quadrature oscillator using two Voltage Differencing Gain Amplifiers (VDGAs) as active devices. Methods: Since the presented oscillator circuit uses only two external grounded capacitors as pas-sive elements, it is quite suitable for monolithic integration point of view. The condition of oscilla-tion and the frequency of oscillation are non-interactive, and can be controlled electronically by tun-ing two separate biasing currents. Non-ideal analysis and sensitivity performance are also discussed. Results: The feasibility of the designed oscillator is justified by the PSPICE simulation results based on TSMC 0.35-µm CMOS process parameters. Conclusion: The effects of the VDGA non-idealities on the proposed circuit are also provided, and the computer simulations based on TSMC 0.35-mm CMOS model parameters are included to evalu-ate the performance of the circuit.