Hello,
I am playing with a DAC38J84 evaluation board mated with an FPGA (Xilinx VC709). The developed system seems good and stable, but a funny thing I find is that the DAC always output the derivative of the original signal which I fed into the FPGA. Say, if I(t) is given to the DAC, then the output O(t) = dI(t)/dt is get.
Figures below show several examples. The left parts are the original waveform stored in the FPGA (only one period shown. FPGA is programmed to repeat it continuously). The DAC's output signals captured on the oscilloscope seem to be the derivative of the input signals.
I doubt there is something in the DAC board that acts as a differentiator, but still have no idea what it is after a close examination of the DAC‘s documentations.
The quick start page of DAC3XJ8X GUI is configured as following while all other tabs are remained as default. I don't think these configurations make any difference, though.
So, could anyone tell me what is the problem? Hopefully this may be a silly issue that can be fixed by a click.
Thank you.
Best regards,
D.X.
