12 A fast-blow SMT fuse for board-level protection
The Littelfuse 0451012.MRL is a 12 A fast-blow surface-mount fuse from the NANO² 451 series, rated for 65 V AC and DC circuits. Its 50 A interrupting capacity at rated voltage means it can safely clear a short-circuit fault up to that level without rupturing — essential for protecting downstream silicon on a crowded PCB.
Parametric fit for your rail
Rated 12 A continuous with a cold DC resistance of 0.0049 ohms — the voltage drop at full load is negligible, under 60 mV, so it won't steal headroom from the load. Melting I²t of 47.97 A²s is the energy let-through before the fuse opens. Use this value to coordinate with downstream components: a MOSFET rated for 50 A²s pulsed avalanche energy will survive a fault behind this fuse; a smaller FET may not. Fast-blow response means it clears quickly on high-overcurrent events — typical for protecting sensitive ICs that can't tolerate sustained overcurrent.
Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm. Supplied in Tape & Reel (TR) or Cut Tape (CT) for pick-and-place assembly.