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JordanD's avatar
JordanD
Icon for New Contributor rankNew Contributor
4 years ago

FIR II Decimation Frequency Response

I'm designing a filter with the FIR II IP. Input data rate is 64 MHz and decimation factor is 8. I want the frequency response to be low pass cut off at 3.2 MHz. The confusing thing is whether the ...
CheepinC_altera's avatar
CheepinC_altera
Icon for Regular Contributor rankRegular Contributor
4 years ago

Hi,


Sorry for the delay. For your information, our Engineering has looked into your simulation and responded that the reason the plot appears to show the cut-off frequency at ~25 MHz is because the fir_inspect.m does not account for the decimation for freqsMhz, which is defined as 0 -> Fsinput/2. To use freqsMhz for plotting the output data, use freqsMhz ./ 8.


Hope this information is helpful.


Please let me know if there is any concern. Thank you.



Best regards,

Chee Pin