I'm using the LM3150, synchronous buck regulator, in a number of designs. Now it is sorted it works well.
Just been using it on a battery charger and at end of charge I set the voltage to zero. Gotcha. The bottom FET is left turned on and the fuse blows because it shorts out the battery.
I use FETs to protect against a reversed battery and to stop the battery discharging into the electronics when the charger is off so an easy fix.
Had me puzzled as to why the fuse blew though.