3 A fast-blow fuse in a 1206 footprint
The Littelfuse 1206SFF300F/32-2 is a 3 A fast-blow surface-mount fuse from the SFF series, rated for 32 V DC with a 50 A interrupting capacity at that voltage — enough to clear a hard short on a 24 V rail or a 12 V automotive bus without rupturing the 1206 ceramic body. Its 0.22 melting I²t and 0.032 Ohm cold resistance mean it tolerates moderate inrush without nuisance opening — a 3 A fuse with this I²t handles a capacitor bank charging current that peaks at 10 A for a few milliseconds, typical for a DC/DC converter input stage.
Obsolete — sourcing through independent channels
A board-spin to a current-production 1206 fast-blow fuse with matching I²t and DC resistance is the long-term fix.
The fuse carries UL recognition — the approval agency listed in the spec — so it is accepted in UL 248-14 compliant designs for secondary circuit protection in power supplies, battery packs, and control boards.