Advanced Digital Power

Advanced Digital Power

DSP IIR Coefficients







DSP IIR Coefficient Calculator

Downloadable Work Files

Mathcad® File


Excel® File


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This webpage and the linked files use different methods for their calculations, each following its own unique computational approach.

Created and Published by Vito D’Erasmo, Copyright © 2025.
Unauthorized copying, in part or in whole, is prohibited without proper citation and referencing.

This tool designs digital signal processing (DSP) filters by calculating DSP coefficients from user-specified frequency characteristics in terms of poles and zeros. It enables users to tailor filter performance precisely to their specifications. The tool outputs the DSP coefficients in the form of bn and an values that can be placed directly into executable code. The code should execute the following equation. The number of coefficients will vary based on the number of poles and zeros.


gn = b0 * fn + b1 * fn-1 + b2 * fn-2 + a1 * gn-1 + a2 * gn-2

Frequency Inputs

Poles

Pole 1 is for an Integrater.
The Frequency in that field is the Integrator Crossover Frequency.
All other poles are breakpoints.

Zeros

The First Line should be Comma Separated Poles.
The Second Line Should be Comma Separated Zeros.

Calculated Coefficients

a1:

a2:

a3:

a4:

a5:

b0: 1

b1:

b2:

b3:

b4:

b5:



The file is formatted as comma separated variables (csv). The first line contains the b coefficients starting from b0. The second line contains the a coefficients starting from a0.
Note that a0 is always 1.