FPGA fft problem

liyisong

FPGA fft problem [Copy link]

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I encountered a problem when doing a project. Please help me.

It is required to collect three vibration signals with a frequency range of 5Hz to 5000Hz. It is planned to use an AD multiplexer to collect three channels. The sampling frequency is 60KHz. Then, is the actual sampling frequency of each channel 20KHz? In this way, can the sampling frequency of each channel be 4 times the signal frequency?

Perform FFT processing on the collected signal to get the amplitude value of the specified frequency point. The specified frequency points are concentrated within 200Hz and are accurate to one decimal place. That is to say, the frequency resolution must be 0.1 to distinguish these signals. In this case, the number of FFT points must be 20K*2/0.1, reaching more than 400,000 (I don't know if I calculated it correctly). Then, is it impossible for FPGA to do it? I think the maximum number of points of the FFT IP core of the 7 series FPGA is only 65536.

If I pass the collected data through a digital filter, filter out all signals with frequencies above 200Hz, and then do FFT, is this process feasible?

Or do you have other ideas? Let's discuss it together.

T_T1111

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q1233

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风过不留痕

20k of data required