Unclear what is driving P5VREG
from what I understood of one PD board with a wire between LMZ (IC22) UVLO pin and EN_A of IRPS (IC28), we were trying to use the UVLO, but I can seem to find what source is driving the P5VREG.
If my understanding of the schematics is correct, it would mean that the rail is only supplied by "phantom" power from P3V3_PG trough 20K, which would not make it enough for the 4.5 V threshold +/- 150mV of histeresis.
maybe @paul.peronnard can shine a light on this when he's back
cc @lipinskimm