TPS2373: From datasheet,may we know what is mean "IEEE 802.3bt (Draft)”?

Hello Bogey. This is a very important development for Power over Ethernet (PoE)!

You can read more about it under FAQs - published here:
e2e.ti.com/.../design_notes

To re-post the main comments:

What’s the difference among IEEE 802.3af, IEEE 802.3at and IEEE 802.3bt standard?
PoE was first introduced in IEEE802.3af in 2003 and the max operating power defined for PSE was 15W. In 2009, IEEE802.3af was replaced by IEEE802.3at and the max power was increased to 30W. In the upcoming release in 2018, IEEE802.3bt will be targeting max power up to 90W. Each new standard release will be backward compatible with prior release(s). The newer standard will embrace and supersede the previous standard(s). For example, the .af standard is now defined as Type 1 (<15W) in the .at standard. And the power range between 15W and 30W are called Type 2. This rule also applies to IEEE802.3bt. There will be Type 3 and Type 4 added to the IEEE802.3bt standard. Everything defined in 802.3af and 802.3at will be covered in 802.3bt.

IEEE802.3at standard (standards.ieee.org/.../802.3at-2009.html)

IEEE802.3bt public space (www.ieee802.org/.../index.html)

I trust this answers your question.

Best Regards,
Thomas Lewis
PoE Applications & Marketing Manager
Power Interface (PI) Product Line
Power Switches, Interface and Lighting (PSIL) Business Unit
Analog Power Products (APP) Division