Dear Team,
Why we have three pins: TPH, TPL and BT but we can't tell which class of PSE is providing power to the PD side?
Or how to know PSE's class at PD side?
Or it is because we can only know PSE type1-4, and we need to decide PD class by ourselves.
Or we won't know PSE's class?
BR
Kevin
Hello Kevin,
I broke apart the table to show the different meanings. First, the red box is .af or .at PSE's. The blue box is .at PSE's only, providing up to 25W (Type 2) power.
The green box is .bt PSE's. This box is further broken down into type 1 power, type 2 power, type 3 power, and type 4 power.
So the signals can help differentiate between which standard the PSE has, ether PoE1 (.af/.at) or PoE2 (.bt). From there the signals can interpret which class is available. So if there is a PoE2 (.bt) PSE providing Class 3 power, there is no way to tell if it is type 3 or type 4. But that does not matter if it is only providing class 3 power.
Does that make sense?
If this post answers your question, please indicate so by marking this thread as resolved. Thank you.
Regards,
Michael P.
Applications Engineer
Texas Instruments
