Working Voltage Range

The PGIA on NI sbRIO devices operates normally by amplifying signals of interest while rejecting common-mode signals under the following three conditions:
  • The common-mode voltage (Vcm), which is equivalent to subtracting AIGND from AI-, must be less than ±10 V. Vcm is a constant for all range selections.
  • The signal voltage (Vs), which is equivalent to subtracting AI+ from AI-, must be less than or equal to the range selection of the given channel. If Vs is greater than the range selected, the signal clips and information is lost.
  • The total working voltage of the positive input, which is equivalent to (Vcm + Vs), or subtracting AIGND from AI+, must be less than the maximum working voltage specified for that range. Refer to the NI sbRIO-9637 Specifications on ni.com/manuals for the maximum working voltage for each range.

If any of these conditions are exceeded, the input voltage is clamped until the fault condition is removed.