Current-mode single-input three-output (SITO) universal filter employing FTFNs and reduced number of passive components

this paper, a new current-mode single-input three-output (SITO) universal f ilter employing FTFNs and reduced number of passive components is proposed. The circuit contains four FTFNs and five passive components, three of them are grounded. It provides simultaneous realisation of low-pass, band-pass and high-pass filter functions without changing the circuit topology and el ements and does not require any parameter matching condition. The proposed circuit enjoys independent control of the parameters omega(o) and omega(o)/ Q. Sensitivity analysis of the filter Shows that it has low passive sensiti vities; omega(o), Q and omega(o)/Q of the filter are insensitive to current tracking errors and omega(o) of the filter is also insensitive to voltage tracking errors of the FTFNs. High output impedances of the proposed univer sal filter enable the circuits to be cascaded without requiring any impedan ce matching device. The theoretical results are confirmed by PSPICE simulat ions.