As a rule of thumb, 32-bit coefficients are sufficient for most designs, though more bits may be required to implement very demanding IIR filter designs. The coefficients of an IIR filter design must be represented accurately in order for the filter to have the intended response. Also, the values calculated internally by IIR filters often span a dynamic range that is too wide for common fractional fixed-point formats. The main reason is that IIR filter coefficients cannot be limited to a fractional range, as can FIR filter coefficients. Choice of ArithmeticĪlthough it is possible to implement IIR filters with fixed-point arithmetic, the use of floating-point arithmetic is greatly preferred when implementing IIR filters of any significant order.
AD2181 COEFFICIENTS TO MATLAB B,A CODE
However, in order to implement an IIR filter successfully, it is important to understand how the IIR filter coefficients should integrate with the code that actually implements the intended IIR filter. Implementing an IIR filter may seem difficult, but it really is not complicated.
After that, the user is responsible for actually implementing the filter using the coefficients provided. The job of an IIR filter design program is to transform a filter specification into a corresponding set of IIR filter coefficients.