100 mA fast-blow fuse for secondary-side protection
The Littelfuse 0451.100NR is a 100 mA fast-blow surface-mount fuse from the NANO² 451 series, rated for 125 V AC and 125 V DC with a 50 A interrupting capacity at rated voltage. This fuse is designed to protect sensitive downstream circuits from overcurrent faults in low-power DC rails or AC control lines, common in telecom, instrumentation, and industrial control boards.
Package and board-fit considerations for rework
Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm, this fuse is suited for automated pick-and-place assembly and reflow soldering. Supplied in tape and reel packaging, it integrates directly into high-volume SMT lines without manual handling.
Electrical characteristics and application fit
With a melting I²t of 0.00138 and a cold DC resistance of 3.1 ohms, this fuse provides fast clearing for short-circuit events while tolerating brief inrush currents from capacitive loads or relay coils.
Approvals and compliance for global equipment
The 0451.100NR carries CSA and cULus approval agency markings, confirming it meets North American safety standards for overcurrent protection in end-user equipment.
Sourcing this obsolete fuse for existing BOMs
For existing designs that require this exact fuse, we source it through independent distribution channels — quantities and pricing are confirmed at RFQ time, and each reel is verified for authenticity and date code.