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  1. #1
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    IIR filter response not infinite

    I just simulated the impulse response in matlab for a first order IIR low pass filter using the command impulse (tf[50],[1 50]). The output seems to be lasting for a finite period. Can anybody clarify?

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    Re: IIR filter response not infinite

    It will asymptotically approach a final value. In real life with finite resolution it will eventually end.



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    Re: IIR filter response not infinite

    Hi,

    A digital system has limited resolution. As long as the variations are within +/-0.5 LSB around the current value you will see no change.
    What else do you expect?

    Btw: Similar with an analog system ... the limit here is "noise".

    Klaus
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    Re: IIR filter response not infinite

    tf([50],[1 50]) is a time continuous transfer function, not a time discrete IIR.



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    Re: IIR filter response not infinite

    Hi FvM

    Thanks for pointing it out. It was a typo. It was actually impulse of (c2d(continuous function)). Just to know more, how far will the response last. In matlab, there isn't any resolution issues.



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