Nth-Order Multifunction Filter Employing Current Differencing Transconductance Amplifiers

摘要

This paper presents a new nth-order current-mode multifunction filter based on current differencing transconductance amplifiers (CDTAs). The proposed circuit, which adopts n current differencing transconductance amplifiers and n grounded capacitors, can realize current responses of low-pass, band-pass and high-pass, without component-matching conditions and changing the topology. The filter also offers the features of low input and high output impedances and enjoys the simple configuration which is suitable for integrated circuit (IC) fabrication. The proposed third-order filter is simulated using PSPICE to confirm the presented theory, and the results have good agreement with the theoretical analysis. The influences of the CDTA non-idealities are also discussed.