Multifunctional Tuned Second-order ARC Filter with Commercially Available Transconductors

The paper presents a voltage-mode second-order multifunctional filter (low-pass, high-pass, bandpass and band-reject) having one input and four low impedance outputs. The proposed circuit employs as basic building blocks operational transconductance amplifiers, namely LM 13700, OPA 660 and or LT 1228. Their transconductance can be continuously controlled by an auxiliary current. It gives the possibility to control electronically the parameters of realized filters. The workability of the given universal biquad has been confirmed by PSpice simulations.