Design and experiment of VDCC-based voltage mode universal filter

Abstract

In the present paper, configurations of the three new voltage-mode universal biquad filters are presented. The first filter is three-inputs single-output (TISO) filter which can realize all the five standard types of biquadratic functions in voltage-mode that is low-pass, band-pass, high-pass, band-stop and all-pass filter with single VDCC. The second filter has single-input and dual-output, which can also simultaneously realize the high-pass and band-pass filter functions. The third circuit is universal filter with single-input and dual-output, which can simultaneously realize low-pass and band-pass filters. Simulation results are given to confirm the theoretical analysis. The presented biquad filters are simulated using TSMC CMOS 0.18 mu m technology. To realize TISO filter with discrete elements VDCC block experimentally generated with operational transconductance amplifier, OPA860. Experimental results of the filter agreed well with the theoretical analysis and SPICE simulations.