Unity / variable gain voltage - mode / current - mode first - order all - pass filters using single Dual - X second generation current conveyor

Abstract

In this paper, two new general topologies for realizing voltage-mode (VM)/current-mode (CM) first-order all-pass filter transfer functions (TFs) are presented. The proposed topologies use single dual-X second-generation current conveyor (DXCCII) and three impedances Z(1), Z(2) and Z(3). Based on the selection of Z(1), Z(2) and Z(3), new VM and CM all-pass filters with unity or variable gains are obtained. The proposed VM/CM filters have high-input/high-output impedances which provide easy cascading at their input/output terminals, respectively. Non-ideal gain and parasitic impedance effects, associated with actual DXCCII implementation, on the performance of the developed topologies are also included. Finally, simulation program with integrated circuit emphasis (SPICE) simulation results based on level 49, 0.25 mu m TSMC complementary metal-oxide-semiconductor (CMOS) technology parameters are given to confirm the theory.