Abstract: In this paper an approximation and realization of multi band elimination active RC filter has been described. Since two Q-factors of the filter are relatively low (less than ten), the fourth order filter with one operational amplifier should be used for cascaded form realization. Sections can be arranged so that the fourth order section is the first. This filter is very suitable for data extraction which are transmitted over power line, because dynamic range is big and the fourth order section more save operational amplifier due to power line tension.
Key words: Active RC filter, multi band filter, sensitivity.