SFP 0603 — 2.5 A fast-acting chip fuse
The Littelfuse 0603SFP250F/32-2 is a 2.5 A, 32 VDC board-mount fuse in the SFP series, housed in the standard 0603 (1608 metric) chip package. It is a surface-mount, fast-acting fuse designed for overcurrent protection on densely populated PCBs where space is at a premium. Rated breaking capacity is 50 A at the rated voltage, meaning it can safely interrupt a fault current up to that level without rupturing or sustaining an arc — a key parameter for secondary-side protection in DC power rails where the available fault current from the bulk capacitor bank can exceed the fuse's interrupt rating.
DC cold resistance is 0.042 Ohms typical. Melting I²t is 0.56 A²s. This is the energy needed to open the fuse element. For a designer, it governs the fuse's ability to ride through inrush current without nuisance opening — a capacitor charging into a 2.5 A rail with a 100 µF bulk cap draws a peak inrush that stays below this I²t threshold for typical soft-start times above 100 µs.
Obsolete — sourcing through independent channels
Littelfuse has marked the 0603SFP250F/32-2 as obsolete. The UL recognition still applies to existing stock; parts carry the original manufacturer's markings and are RoHS-compliant per the original production date code. No pin-compatible drop-in replacement from Littelfuse is documented — any functional substitute will require a PCB respin or parametric revalidation.
0603 footprint and rework profile
Package size is 0.063" x 0.032" x 0.032" (1.60 mm x 0.81 mm x 0.81 mm) — the standard 0603 chip footprint. The nickel-tin plated terminations are compatible with standard SAC305 solder profiles; peak reflow temperature should not exceed 260 °C per JEDEC J-STD-020 for the component body. Operating temperature range is -55 °C to 125 °C, covering the full industrial and automotive under-hood ambient envelope. The fuse element is hermetically sealed in the ceramic body — no moisture sensitivity level (MSL) concern, though standard ESD handling precautions apply during rework.