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ADuCM355 AD5940 ADC -> DFT sub 1 Hz sampling window too short

Hello,

I am running an impedance measurement using the evaluation board ADUCM355QSPZ. I'm interested in sampling low excitation frequencies between 0.016 - 0.5 hz. A 0.016hz cycle takes ~62 seconds. The ADC fills the DFT engine too fast to give a meaningful result per analysis -- can the ADC sampling rate be changed to fill the DFT over 60+ seconds instead?

Relevant hardware registers / settings:

SYSCLKDIV ADCCLKDIV AFEPWR AFEBW amplitude dc_bias hsdac_rate_div HSDACGAIN EXCITBUFGAIN HSTIADIODE HSTIARTIA (Ohm) HSTIACTIA (pF) ADCPGA ADCRATE (Hz) adc_filter ADCSINC2OSR ADCSINC3OSR ADCAVGNUM DFTSRC DFTNUM DFTHANNINGWIN
1 1 HP AUTOSET 1 (2047) 0.8 7 1 2 ON 160K 31 9 800K sinc3+sinc2 22 5 16 SINC2NOTCH 16384 ON

Thank you.



minor changes
[edited by: cosmos at 1:11 AM (GMT -4) on 17 Apr 2021]