LTC4269-1 start-up problem

Why do I have an unstable output using the LTC4269-1?  What you see in the scope is measured between +12VE and DGND. Refer to my schematic. Other than equivalent component replacements, it matches the DC1335B-C evaluation board. I've also attached my bill of materials.

What is interesting is if I apply heat the problem goes away. What I mean by that is I heat the area around the LTC4269-1 with hot air that would normally be used for soldering and the output spontaneously jumps to 12.1 V and is stable. I can power a 6.5 Ohm load with just 100 mV sag (down to 11.99 V) This is repeatable.


I am using a type 2 class for PSE for the supply. Phihong switching power supply. 802.3at TYPE 2 compliant. Model POE36U-1AT-R

changed file format of the BOM from excel to pdf
[edited by: current view at 4:43 PM (GMT 0) on 24 May 2019]
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