I intend to use the FMCDAQ2 ADC input to measure the voltage levels of a bus signal. By its nature, the bus will hold at "high" and "low" voltage levels for significant periods of time. My initial attempt at this shows these DC levels as exponentially decaying to zero, apparently due to the high-pass filter prior the input to the the ADC. Can someone recommend a modification to the FMCDAQ2 board to allow the ADC to work down to DC?
My initial thought is to remove transformer T100. T101 appears to be doing single-ended to differential conversion, which probably needs to remain intact. Would C108 and C187 need to be replaced with 0-ohms? Am I missing anything?
Any suggestions for this would be appreciated!