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ADS5263EVM: TSW1400 SNR Calculation

user5123505
Prodigy 20 points
Part Number: ADS5263EVM

Hello,

I work on the ADS5263EVM and TSW1400 board.

I don't understand why the graphic reading SNR is different from the SNR display on the left column ? How is the SNR calculated (on the left column?

  • 0
    Prodigy 20 points

    I forgot to attach this figure below. From what the 40,7 dBc comes ? I can read about 71dB of SNR, isn't it ? Where is my error ? (with a bandwidth of 4 MHz around the fundamental).

    How could I have directly ths SNR (in dB) within 4 MHz bandwidth around the 12,5 MHz.

  • 0 in reply to user5123505
    TI__Expert 4145 points

    Hi there,

    Please read the following thread to get a better understanding of how the SNR is calculated.

    https://e2e.ti.com/support/applications/medical/f/30/t/624259#pi239031350=2

    The key point is that "The dB level of the "visual noise floor" you see above is dependent on the number of points used in HSDC pro's FFT but the total noise power remains the same as the sampling frequency(and hence Nyquist BW) remains the same. The SNR number is calculated using the total noise power minus some harmonics as stated in the datasheet, not the power level of a single frequency bin."

    Sincerely,

    Olu