Electronically tunable current mode biquad filter based on single VDTA and grounded passive elements

This paper presents a new filter structure based on only single voltage differencing transconductance amplifier (VDTA) and three grounded passive elements and has capability to low pass (LP), band pass (BP), high pass (HP), band reject (BR) and all pass (AP) biquad filtering functions at an explicit current output by the use of appropriate selection of three current input signals. Hence, it is fully integrable, canonical in nature and universal current-mode (CM) biquad. Besides it, the proposed filter also enjoys few more desirable features such as low active and passive sensitivities, low power consumption and orthogonal tunability of pole frequency and quality factor by electronic means. The presented filter is simulated using PSPICE in 0.18μm CMOS process. KeywordVDTA, Biquad, Tunable filter, Current-mode