3.15 A fast-blow in a 2-SMD footprint
The 04513.15NRL is a Littelfuse NANO²® 451 series surface-mount fast-blow fuse rated for 3.15 A continuous current at 125 V AC or DC. Its 50 A breaking capacity at rated voltage means it can safely interrupt a short-circuit fault up to that level without rupturing — a critical parameter for secondary-side protection in power supplies and DC-DC converter outputs where the available fault current from the bulk capacitor bank can exceed the fuse's interrupt rating if undersized.
Board-level protection for DC rails
Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm, this fuse occupies minimal PCB real estate and is compatible with standard pick-and-place equipment. The 0.0215 Ohm cold DC resistance keeps voltage drop low — at 3.15 A the I²R loss is roughly 0.21 W, which is manageable for most layouts but should be considered in thermally constrained designs. The melting I²t of 1.92 A²s is the energy required to open the element. For inrush-sensitive loads like capacitive input filters or motors, compare this to the I²t of the transient — if the inrush pulse exceeds the fuse's I²t, the fuse may nuisance-open. The fast-blow response time means it clears quickly on overcurrent, but offers less tolerance to short-duration surges than a time-delay type.
Active production with global approvals
Listed as active in production, the 04513.15NRL carries CSA, PSE, and UL approvals — covering North American and Japanese regulatory acceptance for equipment-level safety.