Obsolete — sourcing the 0451010.MR
The 0451010.MR is listed as Obsolete by Littelfuse, meaning the manufacturer no longer produces this NANO²® 451 series fast-blow SMD fuse.
Ratings and what they mean for your board
Rated 10 A continuous at 125 V AC or DC — the fast-blow response clears overcurrents quickly, protecting downstream components in a 125 V rail. Breaking capacity is 35 A AC and 50 A DC at the rated voltage — this is the maximum fault current the fuse can safely interrupt without rupturing. For a 125 VDC circuit, a 50 A prospective short is the ceiling. Melting I²t of 26.46 A²s characterises the energy to open the element — relevant for coordinating with upstream breaker trip curves in a protection scheme. DC cold resistance of 0.0056 Ohms means the voltage drop at 10 A is about 56 mV — negligible in most low-voltage power paths.
Housed in a 2-SMD square end block measuring 6.10 mm x 2.69 mm x 2.69 mm — the low profile suits dense PCB layouts where height is constrained.
Approvals and compliance
Approved by CSA, PSE, and UL — these marks certify the fuse meets North American and Japanese safety standards for overcurrent protection.