High input and low output impedance voltage-mode lowpass, bandpass, and highpass active-R filter
A novel filtering topology with a single input and three outputs (SITO) employing a single four-terminal current feedback amplifier (CFA) with an external compensation pin, such as AD844, two operational amplifiers (OAs), and as many resistors is presented. The circuit offers the features of simultaneous realization of lowpass (LP), bandpass (BP), and highpass (HP) filtering functions, free from component matching conditions, cascadability due to high input and low output impedances, orthogonal/independent adjustment of the filtering parameters, and low active and passive sensitivities. PSPICE simulation results are included to confirm the theoretical results.
cfa analog filters high input and low output impedance circuit