Electronically Tunable Single-Input Multi-Output Current- Mode Biquad Filter Suitable for Easy Cascading

Abstract

This paper presents a new current-mode (CM) multi-function filter with one input and three outputs. The filter uses only three multi-output inverting second generation current conveyors (ICCIIs), two grounded capacitors and two MOS resistors. Without using any external passive elements, the proposed circuit can simultaneously realize lowpass (LP), bandpass (BP) and highpass (HP) responses without any matching or cancellation conditions, all at high impedance outputs which is important for easy cascading in CM operation. The bandstop (BS) and allpass (AP) responses can be obtained by connecting appropriate output currents directly without using additional active elements. The parameters ωo and Q, can be electronically tuned by adjusting the bias voltages of the MOS resistances. The proposed circuit enjoys low sensitivities.