A Novel Current-Mode KHN-Equivalent Biquad Using Three CFTAs
Norbert Herencsar, Kamil Vrba and Jaroslav Koton
In this paper a novel current-mode KHN-equivalent (Kerwin-Huelsman- Newcomb) circuit structure using CFTAs (Current Follower Transconductance Amplifier) is presented. Possible internal structure of the CFTA is illustrated. The KHN-equivalent biquad filter has been designed using the signal-flow graph method. The proposed circuit employs three CFTA elements and two grounded capacitors. The advantage of the structure presented in this paper is that the outputs of the filter are at high impedance and hence it is not necessary to use other auxiliary active elements. The properties of the proposed filter have been verified by sensitivity and AC analyses in the PSPICE program.
Keywords: Current Follower Transconductance Amplifier (CFTA), Current-mode circuit, KHN-biquad.