What the ratings mean for your protection design
The 0603SFS300F/32-2 is a Littelfuse SFS series slow-blow fuse in a 0603 (1608 metric) surface-mount package, rated 3 A at 32 VDC with a 50 A breaking capacity at rated voltage. The slow-blow response time means it tolerates high inrush current pulses without nuisance opening — the 0.87 melting I²t tells you the energy needed to clear it, so you can check whether your circuit's worst-case surge stays below that threshold. The 0.031 ohm DC cold resistance is low enough that self-heating at 3 A is manageable, but you still need to derate for ambient temperature above 25 °C. UL approval means the fuse has passed UL 248-14 testing for branch-circuit protection — a requirement for many North American OEM panels and end-equipment listings.
Littelfuse has marked the 0603SFS300F/32-2 as obsolete. No stock-holding claim is made; availability is verified per inquiry.
The 0603 (1608 metric) footprint is standard — 1.60 mm x 0.80 mm with a 0.80 mm seated height. The tape-and-reel packaging is compatible with standard pick-and-place assembly. The fuse is a two-terminal chip, so layout is straightforward: the pad geometry follows the Littelfuse recommended land pattern in the SFS series datasheet, with a 0.50 mm gap between the two pads.