Realization of Fourth Order Multifunction Filters Using Operational Transresistance Amplifier

Abstract

Design of analog filters, using single Operational Transresistance Amplifier (OTRA) as the active current mode building block, is presented. Five types of filters have been designed namely Low Pass, High Pass, Band Pass, All pass, and Notch.  The order of the proposed filters is four. The theoretical results are verified with PSPICE simulation using 0.5mm CMOS process parameters provided by MOSIS (AGILENT). Frequency responses for the presented filters are shown in the paper. The proposed filters offer the following important features: use of single operational transresistance amplifier as active element, low sensitivity, cut off frequency can be adjusted by varying the frequency scaling factor. Simulation results agree well with the theoretical values.

Keywords: Analog filters, Fourth Order Voltage Mode Filters, OTRA