A Versatile Cell of Multimode First‐Order Universal Filter Using VCIIs

Abstract

This article presents a new generic core cell for designing the first‐order universal filter employed second‐generation voltage conveyor (VCII + ). With appropriate admittance selection, the proposed core cell can derive four different filter types, namely, low‐pass, high‐pass, inverting all‐pass, and noninverting all‐pass functions and encompassing four basic modes: current mode (CM), voltage mode (VM), transimpedance mode (TIM), and transadmittance mode (TAM). The primary feature of the proposed filters is the ability to cascade the circuit easily, eliminating the need for an extra buffer. The proposed circuits were confirmed by 0.18‐μm TSMC CMOS process technology simulations. Numerous simulation results are included to verify the validity of the proposed circuits. Moreover, the experimental results of some proposed circuits from the commercial device built around AD844 agree well with the theory.