TPS23752: Is a buck converter available for the TPS23752?

Hi.

I have a question.

I'm going to design the PD(Powered Device) of PoE(Power over Ethernet).

(IEEE 802.3at. / 25W)

I will use TPS23752parts. 

   ** If you have any good parts other than TPS23752, please recommend it

       (I usually buy parts from Mouser, Digikey, and Ti. As I looked it up, other models are out of stock.)

In the TPS23752 component recommendation circuit, a power conversion element is designed as a transformer.

I'm gonna use a buck converter ( DC DC Converter)

There's no problem using the buck converter, right?
I don't need a isolate circuit.

Are there any Application notes for reference? use a buck converter(not transfomer)

Thanks Please.