Below is text from the users guide for this part.It references an application note I can not find.Can you assist in providing this?
This LM5072 based 5V out 25W POE+ PD power supply isfully compliant with IEEE 802.3at standard. This eval boardconverts 48 Vdc to 5 Vdc. It can deliver up to 25W power as specified by the IEEE 802.3at standard. It has a 2 event detectioncircuit which can identify the PSE as either Type one or Type two.
( See National Semiconductor Application note “Fully Compliant IEEE 802.3at Interface Using the LM5072/LM5073” for details )
Ed WalkerTexas Instruments ACAT/DCAT Support
Check the following link.
http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=snvu110&fileType=pdf
Note that the app note was created by the PADC group in National Semiconductor time. I have hard time to track all related documentation and design files.
Thanks,
Youhao Xi, SVA PPD PHX Design Center
The file you recommend is already on the web:LM5072 5V out 25W IEEE 802.3at Compliant POE+ PD Power Ref Design User Guide (PDF File 1.48 MB) SNVU110
SNVU110 is the document that contains the text:
This is the app note we are looking for.
I see what you are looking for. I am going to send your request to some colleagues ever worked at PADC and see if they know whereabout of the referred app note. On the other hand, Figure 3 of SNVU110 seems to be the additional circuit for 802.3at compliance.
I just wanted to make sure it was understood that we have the TPS23754, 754-1, 756, TPS2378, 79, TPS23751, 52 parts that were .at compliant.
We were able to find the original of the app note. It is marked preliminary, I am not entirely sure if it was ever properly published but the board operated correctly and the waveforms are accurate. 1680.LM5072 802.3at POE+_App_Note.pdf