Insensitive Current-Tunable Current-Mode Multifunction Filter with Minimum Components Using Multi-Output Current Followers

This paper describes a current-mode multifunction filter with a minimum number of active and passive elements using multi-output current followers (MO-CFs) as active elements. The proposed filter consists of only three MO-CFs and two grounded capacitors, which can simultaneously realize all the five standard biquadratic filter functions from the same configuration. The filter not only offers an independent electronic control of the natural angular frequency (w(o)) and the quality factor (Q), but also provides the absence of the external passive resistors. Moreover, the parameter sensitivities are all very low.