What Does High Impedance Mean in the PXIe-6555/6556 Specifications Manual?

Updated Nov 12, 2019

Reported In

Hardware

  • PXIe-6555
  • PXIe-6556

Issue Details

I'm looking through the PXIe-6555/6556 Specifications Manual for the input impedance for the board, and the spec states the following:
What is the value of High-impedance for my input?

Solution

The spec is listed as High-impedance because it is not a constant value or linear.  However, this board is very low leakage compared to the previous generation of HSDIO boards, and thus will have much higher input impedance.

You can expect an input impedance >100 MOhm at typical operation conditions with the board.  At higher positive voltages, you will have much higher input impedance of around 1 GOhm.  Also, note the high impedance leakage spec we provide in the manual is <5 nA.