LTC4266 and POE specs info

Hi,

I am designing a carrier board with 16 POE PSE channels in addition with 4*4 ports marvell 88E1548 phy. For the moment, i don't know if the distant devices will draw more than 12.95W so i considered the LTC4266 POE+ PSE as a start.

I have read some of the specifications about POE, but i still don't get some of the features.

Let's assume that i want to give a certain margin to my PD device and i use a class 4 PD (LT4275B) . My questions are :

  • during the classification stage, does the PSE detects the signature of the PD by sending 25.5W to the device? (if yes, i will need a 400W or more power supply :/ )
  • if my device is not drawing more than 10W (during normal processing), will it still work efficiently?

Sorry for the silly questions, i'm not familiar with POE.

Thank you in advance.

Best regards,

John