SMD fast-blow fuse for secondary-side protection
The 045101.6MRSN is a 1.6 A, 125 VAC fast-blow SMD fuse from Littelfuse's NANO² 451 series. It is designed for board-level overcurrent protection where fast response to short-circuit faults is required. Rated breaking capacity is 50 A at the rated voltage — sufficient for interrupting fault currents in most secondary-side DC/DC converter outputs, point-of-load regulators, and low-power AC circuits without rupturing the package. The melting I²t of 1.06 gives a clear window for inrush coordination: a capacitor bank or motor start drawing a transient above 1.6 A must clear before the fuse element reaches its melting energy threshold.
Package, mounting, and thermal envelope
Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm, the fuse mounts directly onto the PCB footprint with standard reflow soldering. The Tape & Reel packaging supports automated pick-and-place for volume assembly. The cold DC resistance of 0.058 Ω keeps voltage drop and self-heating low at rated current. Approved by CSA and UR — the fuse carries North American safety certification for use in equipment listed to UL 248-14 and CSA C22.2 No. 248.14.
Lifecycle and supply posture
No minimum order quantity restrictions beyond the standard reel increment.