NANO²® 451 — 750 mA fast-blow fuse, now obsolete
The Littelfuse 0451.750MR is a 750 mA fast-blow surface-mount fuse from the NANO²® 451 series, rated for 125 V AC and DC with a 50 A breaking capacity at rated voltage. Its 0.185 melting I²t and 0.245 Ohm cold resistance make it suitable for protecting sensitive board-level circuits where fast opening is required. The part is now classified as obsolete by Littelfuse, meaning no ongoing production — sourcing is through surplus or broker channels.
Housed in a 2-SMD square end block package measuring 0.240" x 0.106" x 0.106" (6.10 mm x 2.69 mm x 2.69 mm), it is a surface-mount fuse designed for reflow soldering onto standard PCB pads.
Compliance and approvals
Approved by CSA and UL, the 0451.750MR carries the typical safety certifications for a board-mount fuse used in North American and Canadian equipment.