Generation of current conveyor-based all-pass filters from op amp-based circuits

It is shown that two of the recently reported voltage mode and current mode current conveyor-based all-pass circuits can be generated from the well known single input op amp all-pass configuration. It is also found that two other voltage mode current conveyor-based all-pass circuits are related directly to the differential input op amp all-pass structure. Several new grounded capacitor all-pass circuits are introduced. A new universal biquad circuit which realizes complex poles and employs a single current conveyor is also given. PSpice simulation results are included.