Voltage-mode universal filters using two current conveyors are presented. These
universal filters can realize low-pass, band-pass, high-pass, notch and all-pass
filters. They have the following advantages: (i) orthogonal control of the natural
frequency and quality factor by grounded resistors, (ii) easily converted into a
voltage-controlled filter, (iii) low component spread, (iv) minimum active and
passive components, (v) without match components except for all-pass
applications, and (vi) low active and passive sensitivities.