Design of VDTA based tuneable universal filters

In this paper, active filter has been designed to realizing high pass, low pass and band pass filter by using single voltage differencing transconductance amplifier (VDTA). In the circuit configuration, active resistance is used by NMOS transistor which provides programmability to the filter. Cutoff frequency of High pass (HP), Low pass (LP) and band pass (BP) filter is 101.67 KHz, 2.26 MHz and 1 MHz respectively. Supply voltage of the filter is ± 900mV.