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Question on ZC706 + FMCDAQ2 reference design

Question asked by damchanhung on Dec 12, 2016
Latest reply on Feb 22, 2017 by rejeesh


I am using No-OS fw for FMCDAQ2 (2016_R2 branch with ADXCVR driver supported).

This latest NO-OS firmware allows user to select line rates when firmware starts.

I use ZC706 + FMCDAQ2 to transmit signal via AD9144, and Zedboard + FMCOMMS3 running LibIIO software to observe the received signal.


Option 1: ADC 1000 MSPS and DAC 1000 MSPS:


                There seems to be 2 output bands.  @300MHz and @1000MHz.  The 300MHz output is not due to external interference because it disappears when I power down the board.  I don’t know if this is problem caused by using Zedboard + FMCOMMS3 running LibIIO software as spectrum analyzer.


                Then I zoom into 1000MHz band.  There are 2 peaks +/- 5 MHz from 1GHz.  What is the JESD204B line rate?  Is this using Cosine for I and Sine for Q?    I understand AD9144 performs interpolation, what is the sampling rate of  waveform in FPGA? 




Option 4: ADC 750 MSPS and DAC 750 MSPS

                This option also outputs a consistent +/- 5MHz peaks beside center 750MHz.  What is the JESD204B line rate?  FPGA MSPS rate? And interpolation?

                How can we achieve consistent 5MHz deviation from center freq? In my opinion, deviation would be scaled according to decrease in center freq.


Any feed back would be appreciated.