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IIR butterworth BPF

U-SK
Genius 5840 points


Hello,

I wold like to implement following IIR filter to any C2000 devices.

≪Filter≫

Pipes : 8

Types : butter worth band path Filter

Orders : 6

Cutoff frequency : User defined

≪ADC≫

Channels : 3

Sampling Rate : 204.8kSPS

Is it possible to work on one of C2000 devices?

When IIR is difficult, it is acceptable if the FFT of 2048 points is within 100 ms.

Is it possible?

Regards,

U-SK

  • 0
    TI__Mastermind 27200 points
    I will ask someone to respond on the FFT and IIR questions. Can you clarify what is meant by "Pipes" in the above question please?

    An issue I see is generating exactly the sampling frequency you require. Is the frequency a firm requirement or can you accept, say, 200 kSPS?

    Regards,

    Richard
  • 0 in reply to Richard Poley
    TI__Mastermind 27200 points
    Also, please say whether you are looking for a fixed- or floating-point solution, Thanks.
  • 0
    TI__Mastermind 20850 points

    Hi,

    U-SK said:
    Is it possible to work on one of C2000 devices?

    Im not sure what "pipes" mean in this context, but you can do a 6th order IIR filter in the fixed point DSP library. It will be implemented as 3 cascaded biquads - I would suggest using the MATLAB script that comes with the IIR module to design the butterworth filter

    U-SK said:
    When IIR is difficult, it is acceptable if the FFT of 2048 points is within 100 ms.

    A 2048 point fixed point RFFT takes 167163 cpu cycles (bit reversal of input + FFT + output split). Assuming you are running a 200MHz processor, that should take 0.835 ms.