Switched-current filter optimization based on evolutionary algorithms

Abstract

This paper describes a way to eliminate the effect of circuit nonidealities on the magnitude frequency response of a circuit utilizing the switched-current technique. The circuit realizes a band-pass filter. The elimination is carried out by optimization based on one of evolutionary algorithms - the differential evolution. The nonidealities are nonzero on-state resistance of the switches and nonzero output conductance of the field-effect transistors implementing the current sources. It is shown that the filter with the current source transconductance values designed according to a common method for ideal components has a significantly different magnitude frequency response when the nonidealities are considered. Hence, the optimization is applied to finding suitable transconductance values so that the difference between the magnitude frequency responses of the ideal and nonideal filter is minimized.