A new MOS-C multifunction filter and its third order oscillator application

Abstract

This paper introduces a novel multifunction filter employing single current operational amplifier (COA) with MOS-C implementation and a third order sinusoidal oscillator as its application. The proposed topology provides voltage-mode high-pass, low-pass, all-pass, band-pass and band-stop filter functions by modifying four passive components. The workability of the circuit is confirmed by PSPICE simulation software using MOSIS 0.18 μm CMOS model parameters and a good consistency observed between theoretical analysis and simulation results. The circuit is supplied by symmetrical voltage of ±0.9 V. Considering the number of input and output terminals, the proposed circuit can be classified as single input single output (SISO) filter. An experimental study using commercially available 844 CE as sub-circuit of COA which verify the workability of the proposed topology is also included. Electronic tunability of the central frequency, MOS-C implementation which is a requirement for integration, simple circuitry, low distortion and operability at low voltage are the considerable features of the introduced circuit.