375 mA fast-blow in 0603 — what the ratings mean for board-level protection
The 0467.375NR is a Littelfuse Series 467 fast-blow fuse rated 375 mA at 32 VAC/DC, in a standard 0603 (1608 metric) surface-mount package. The fast-blow response means it clears on moderate overcurrents quickly — suited for protecting ICs and sensitive circuitry where a temporary overload must not propagate. Breaking capacity is 50 A at the rated voltage — the fuse can safely interrupt a fault current up to 50 A without rupturing or sustaining an arc. For a 375 mA rail, that is over 130× the nominal load, covering most secondary-side faults in a 32 VDC power distribution.
I²t and cold resistance — sizing the fuse into the circuit
Melting I²t is 0.0035 A²s — this is the energy needed to open the element. For a 375 mA fast-blow, the low I²t means it responds to short-duration pulses (inrush, capacitive charging) faster than a time-lag fuse, so the downstream silicon sees less let-through energy. DC cold resistance is 0.3 Ω — at 375 mA the voltage drop is roughly 113 mV.
Active production — sourcing posture for this order code
Approved under CSA and UL — the fuse carries agency recognition for use in equipment destined for North American markets. Operating temperature range is -55 °C to 90 °C, covering most indoor and telecom-grade outdoor enclosures without derating.