POE-PD-POWER-REF, LM5072 with 5 Vout, 25W IEEE 802.3at Compliant POE+ PD Power Reference Design

POE-PD-POWER-REF, LM5072 based 5V out 25W POE+ PD power supply reference design was prototyped to be fully compliant with IEEE 802.3at standard. The design converts 48 to 5 VDC. It can deliver up to 25W power as specified by the IEEE 802.3at standard. It has a 2 event detection circuit which can identify the PSE as either Type one or Type two. The 2 event detection circuit is located on the bottom layer of the PC board. In those applications where this 2 event detection feature is not required, the user only needs to populate top layer components. The input current limit is 800 mA. The efficiency of this design is high enough to keep input current under 800mA at 38Vin full load. The input under voltage lock has 7V hysteresis with 38V rise and 31V fall