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Using AD7401A with SINC4 Filter with Decimation Factor 128?

In order to increase the bandwitdh and the SNR of the acquired data we would like to use a SINC4 Filter with a decimation factor 128 instead of a SINC3 Filter with a decimation factor 256. With these measures we hope to increase the bandwidth to 150 kHz while still retaining a SNR > 80 dB.

Does this make sense with the AD7401A or are we missing something? What SNR would you expect?

Thanks a lot for your help

Bernd

  • The AD7401A was only characterized with the filters shown in Figure 26 in the data sheet, sinc1, sinc2 and sinc3. We don't have any data for a sinc4 filter.

    Looking at the graph, with a sinc3 with a 128 decimation rate the performance is almost 80dB. You should see an improvement with a sinc4 so I expect you will get better than 80dB SNR figure with a sinc4 and a 128 decimation rate.