In this paper, a design procedure for the realization of all current-mode biquadratic transfer functions is presented. The synthesis technique is deduced from a signal flow graph representation using current follower transconductance amplifiers (CFTAs). The proposed configuration has single low-impedance input and five high-impedance outputs, and comprises three CFTAs and two grounded capacitors. No passive resistor is required for the circuit realization, thus it is an active-C structure suitable for integration.

Keywords: Signal flow graph (SFG), Current follower tranconductance amplifier (CFTA), Biquad filter, Current-mode circuit, Resistor-less circuit