Simple Multi-Function Fractional-Order Filter Designs

A multi-function fractional-order filter topology, constructed from 2 MOS transistors only, is introduced in this paper. The required time-constants are realized through the utilization of the small-signal transconductance parameter of the MOS transistor, offering electronic adjustment of the frequency characteristics of the derived filters. The main attractive offered benefit, in comparison with the literature, is the significant reduction of MOS transistor count and, consequently, the reduced power dissipation. The behavior of the filters is evaluated using the Cadence software and MOS transistor models provided by the $0.35\mu m$ Austria Mikro Systeme CMOS process.