Spare pair termination.
Terry, Sterling, Alan, et al.
I have questions concerning high frequency termination, especially the
spare pairs.
How should the spare pairs be terminated in the PD and PSE?
Or more specifically:
What termination is needed for pairs 4&5 and 7&8?
Differential:
Is a differential termination required for these pairs?
Can they be shorted?
Common mode:
Is a common mode termination to ground(?) required?
Pair to pair mode:
Is a pair to pair termination required?
If a PD can accept power from signal pairs and spare pairs, is isolation
required.
If a PSE is designed for Environment A, is isolation required between
ports?
Please excuse my ignorance. If you think this is inappropriate, please
state so.
Dieter Knollman