What is solution for mismatch between ADS129x sampling-rate(SPS) AND HWAFFT's pts on C5515 ??

Ahn min hee

Prodigy 120 points

Hi~.

We development with ADS129x & C5515 for ECG FE solution.

Recently, we find circumstance on above "title".

Example)

A. ADS129x have sample rate setting parameter list: 250SPS or 500SPS or 1000SPS, etc,

B. HWAFFT pts(C5515 built-in) is 256pts or 512pts or 1024pts ...

thus, it is differ(or mismatch) number of data between A & B.

AND its situation is not only problem of data size, but also frequency precision reliability. <- this is more serious problem.

What is solution of this ?

thanks, a lot.

over 13 years ago

0 Mark M over 13 years ago

TI__Mastermind 30140 points

Hello,

Typically, the input to the FFT is windowed, then zero-padded to fit the power-of-2 FFT length. For example, add 6 zeros after the 250 samples and compute a 256-pt FFT.

Zero-padding also has an effect on perceived frequency resolution that may be useful.

What do you mean by frequency precision reliability?

Some useful links: 1, 2, 3

Hope this helps,
Mark

0 Ahn min hee over 13 years ago in reply to Mark M

Prodigy 120 points

Thanks, a lot.

Your mention help to us, really.

We refer your answer to our work.

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What is solution for mismatch between ADS129x sampling-rate(SPS) AND HWAFFT's pts on C5515 ??