A number of digital signal processing applications use controlled IIR digital recursive filters. The word " controlled " refers to filters whose structure ratios clearly depend on the cut rate or boundary frequencies. Controlled IIR filters can be synthesized using a variety of tools to compute traditional, uncontrolled IIR filters. The article dealt with the synthesis uncontrolled IIR filters and analyzed the suitability of the presentation of the results of synthesis for the construction of controlled IIR filters. The design techniques based on MATLAB (2021a) and the fundamental concepts of IIRButterworth digital filters were described and explained. The composited signal was processed by the analyzed filter to find whether it met the filtering progress criteria. To check the calculated filters, the Simulink prototype was used, as well as FDA tool of signal processing toolbox. Based on the results obtained, a conclusion was made about the applicability of the MAT LAB (2021a) system for the synthesis of controlled digital recursive IIR-Butterworth filters. The analyzed technique was more efficient, faster, decreased the tasks and found the results are satisfying.
