The Littelfuse 0603SFF250FM/32-2 is a 2.5 A fast-blow surface-mount fuse in the SFF series, rated for 32 V DC with a 35 A breaking capacity at that voltage — meaning it safely interrupts a fault current up to 35 A without rupturing the 0603 ceramic body. The 0.115 melting I²t figure tells you how much energy the fuse element absorbs before opening — a key parameter for coordinating with downstream components and verifying the fuse holds through the inrush pulse of a capacitive input or a DC-DC converter start-up.
Package, mounting, and thermal envelope
Housed in a standard 0603 (1608 metric) footprint, this fuse is intended for reflow soldering onto a PCB — the 0.032 Ohm cold resistance means the voltage drop at 2.5 A is about 80 mV, negligible for most low-voltage rails but worth checking if the load is sensitive to supply droop.
Lifecycle reality and sourcing posture
No pin-compatible drop-in replacement is documented by Littelfuse, so a board spin or a parametric search for a 2.5 A fast-blow 0603 fuse with UL recognition is the practical next step for new designs.