A voltage-controlled current source, one of the controlled sources, has been used primarily for realizing the gyrators. This paper proposes a method of realizing an active RC filter using directly VCCS's as the active element. Also, this paper presents various circuits capable of obtaining the low-pass, band-pass, high-pass, and all-pass functions as typical applications.

In this letter, a realization of current-mode active filter using current followers as active element is described. We show the constructions of second-order lowpass, highpass and bandpass filters. The high-order filters can be realized by a cascade connection of these second filters. As examples, the second-order lowpass and highpass filters are designed for frequency of 5 MHz. The effectiveness of the proposed method is demonstrated through SPICE simulation.