CMOS programmable universal filter using CCTAs

This paper presents a new CMOS programmable universal filter using three current conveyor transconductance amplifiers, two grounded capacitors and four grounded resistors. Unlike previous universal filters, low-pass, high-pass, band-pass, band-stop and all-pass filtering functions of proposed universal filter can be programmed using bias current. The angular natural frequency of all filtering functions can be controlled electronically using other bias currents. The proposed structure is favorable for integrated circuit implementation. The proposed filter has been simulated sing PSPICE simulators to verify the presented theory.