{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0451.630NR","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0451.630NR","canonicalUrl":"https://icboms.com/littelfuse-inc/0451.630NR","factsUrl":"https://icboms.com/api/mcp/products/0451.630NR","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 series, 0451.630NR, 630 mA, 125 VAC/VDC, fast blow, 2-SMD square end block, surface mount fuse.","salesMarkdown":"## 630 mA fast blow SMD fuse — the Littelfuse 0451.630NR The 0451.630NR is a 630 mA fast-blow surface-mount fuse from Littelfuse's NANO²® 451 series, housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm. Rated for 125 VAC and 125 VDC, with a breaking capacity of 50 A at rated voltage — sufficient for clearing faults on low-voltage DC rails and AC control circuits without cascading upstream. The 0.1381 melting I²t figure tells you the energy required to open the fuse element — a key parameter for coordinating with downstream semiconductor protection and for sizing the fuse to survive inrush without nuisance opens. ## Obsolete — sourced through independent channels Littelfuse lists the 0451.630NR as obsolete. For existing BOM lines, this part is available through independent distribution — quantities are confirmed at RFQ, and each lot is verified for authenticity and compliance. If you are qualifying a replacement, the NANO²® 451 series shares the same footprint and ratings across current values; a 630 mA fast-blow alternative from a different series would require board-level re-qualification for the I²t and voltage derating. ## Approvals and operating envelope Carries CSA and cULus approval — accepted for North American and Canadian equipment listings where branch-circuit protection is not required.","metaTitle":"0451.630NR Littelfuse NANO² 451 630mA Fast Blow SMD Fuse","metaDescription":"0451.630NR Littelfuse NANO² 451 series, 630mA fast blow SMD fuse. Obsolete. Sourced to order against RFQ via independent distribution.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"Littelfuse Inc.","Color":"-","Series":"NANO²® 451","Package":"Tape & Reel (TR)","Fuse Type":"Board Mount (Cartridge Style Excluded)","Melting I²t":"0.1381","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Obsolete","Approval Agency":"CSA, cULus","lifecycle_stage":"unknown","Size / Dimension":"0.240\\\" L x 0.106\\\" W x 0.106\\\" H (6.10mm x 2.69mm x 2.69mm)","DC Cold Resistance":"0.2022 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"630 mA","Operating Temperature":"-55°C ~ 125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.5926","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/b741f1b0e0a9e21e6a76cce2b8d96e45.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What compliance documentation does Littelfuse provide for the 0451.630NR?","answer":"The fuse carries CSA and cULus approval, indicating it meets North American safety standards for overcurrent protection. RoHS and REACH compliance documentation is typically available from the manufacturer or distributor upon request."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0451.630NR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/0451.630NR when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-20T14:34:45.345Z","lastPublished":"2026-07-20T14:34:45.345Z","indexable":true}}