GIC based third-order active low-pass filters

Third-order low-pass filters are analyzed. Two different configurations of general impedance converter (GIC) based filters are compared to two Sallen and Key (SAK) based structures. For GIC-based third-order filters, realization procedures are given. The transfer functions and the component values for the third-order filters with Butterworth response are presented. Sensitivity analysis is done, and the results of Monte Carlo runs, as well as Schoeffler sensitivities are shown. The best results are obtained with the GIC-based filter which uses four capacitances for the realization.