I’ve designed a SMPS with the MP9485. Schematic enclosed.
With a lab power supply @ 48V it works fine, but any kind of lipo, with intergrated bms, or jus t flicking a switch to give the IC instantly 48V will keep the regulator in an limbo, giving out maybe 60% of the voltage it’s trying to regulate to.
VINnom: 48V, range: 42-58V
with a 120 ohm input resistor, the IC will start every time and regulate 5V with no problem
Here is the 5V rail when it has failed to start.