MOS-C realization of KHN biquad using inverting current feedback operational amplifiers

Kerwin-Huelsman-Newcomb (KHN) biquad topology using the active element called inverting current feedback operational amplifier (ICFOA) is presented. The circuit provides second order lowpass, highpass and bandpass filtering functions simultaneously. The resistors in the filter are realized with MOS transistors by making use of opposite potentials at the input terminals of ICFOA. The resulting circuit contains only transistors and capacitors leading to MOS-C realization. To verify the theoretical analysis, PSPICE simulation results, which are obtained by using CMOS realizations of ICFOA, are included.