Single-input three-output dual-mode universal biquad realization based on floating-current-source building blocks

A novel dual-mode universal biquadraic filter with one input and three outputs is presented, which contains only two floating current sources (FCSs), and four external passive components. The presented filter exhibits the following properties : capable of working either voltage-mode or current-mode, electronically controllable of the natural angular frequency (Ωo) by means of the transconductance gains, independent grounded-resistance control of the quality factor (Q), simultaneous realization of all the three basic filtering signals, no component matching constraints and low active and passive component sensitivities. To confirm the theory, the proposed circuit is simulated with PSPICE program using TSMC 0.25-μm CMOS technology.