A First Order All Pass Filter and Its Application in a Quadrature Oscillator

This paper presents an all pass voltage mode filter based on recently proposed active building block namely differential voltage current conveyor transconductance amplifier (DVCCTA). The proposed configuration uses single active and two grounded passive components which makes it suitable for IC implementation. Its input impedance is high and output impedance is low, hence suitable for cascading. The practical design problems due to non-idealities of DVCCTA have also been addressed. Moreover, as an application, a quadrature oscillator is designed using the proposed all pass circuit which provides both voltage and current outputs. SPICE simulation using 0.25 μm TSMC CMOS technology parameters are included to show the workability.