NI 654x Termination Summary

NI Digital Waveform Generator/Analyzer

NI 654x Termination Summary

The following table provides a high-level summary of the termination considerations for your NI 654x. Click a title for more information about that type of termination.

Source Transmission Line Termination (Load)
Zs = 50 Ω Zo = 50 Ω Zt = Open (Tristate) or Unterminated
Works for all except most demanding applications
Zt = 50–300 Ω
Recommended for better signal integrity.
Termination Transmission Line Source
Zt = 10 kΩ 50 Ω Zs = 50 Ω
This configuration works well for most applications.
Zs < 50 Ω
This configuration is not recommended because of the mismatch on both ends.
The recommended setup is to increase Zs to 50 Ω by adding series resistance at the source.
Zs > 50 Ω
This configuration is not recommended because of the mismatch on both ends.
Note  You must reduce the operating frequency significantly to allow the signal reflections to settle down. You must reduce the frequency proportional to cable length and impedance mismatch.