Frequency tunable universal current-mode filter based on CCCII± and OTA

A simple multifunctional active filter was presented,whose circuit was constructed with two dual current output CCCⅡs(CCCⅡ±),one operational transconductance amplifier(OTA)and two grounded capacitors.The biquad with only one input could realize low-pass,high-pass,band-pass,band-stop and all-pass filter characteristics by choosing appropriate current output branches.The characteristic parameters also could be tuned by adjusting the bias currents and the capacitors.As well as the tunable frequency,the proposed circuit enjoyed very low sensitivities with respect to the circuit elements.Finally spice simulation for an actual circuit was conducted,and the results showed that the proposed circuit was valid and effective.