CFA based fully integrable KHN biquad

A fully integrable biquad using current feedback amplifiers (CFA) as active devices and a canonical number of capacitors is presented. It realizes the classical Kerwin-Huelsman-Newcomb (KHN) structure through the use of grounded capacitors and MOS transistors, which permits a full integrability. The high-pass, band-pass and low-pass responses are simultaneously available. All the other kinds of responses can be realized by adding a further CFA and other MOS transistors. The proposed circuit has attractive characteristics, as the possibility to independently control the transfer function coefficients and the possibility to be directly inserted within cascaded configurations. The theoretical analysis of the circuit is followed by some PSPICE simulation results in agreement with the theoretical findings.