{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0451001.MR","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0451001.MR","canonicalUrl":"https://icboms.com/littelfuse-inc/0451001.MR","factsUrl":"https://icboms.com/api/mcp/products/0451001.MR","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. NANO²® 451 series, board mount surface mount fuse, 0451001.MR, 1 A, 125 V AC/DC, Fast Blow, 2-SMD square end block package, Tape & Reel.","salesMarkdown":"## 1 A fast-blow SMD fuse — obsolete, last-time-buy sourcing The 0451001.MR is a Littelfuse NANO²® 451 series surface-mount fuse rated 1 A at 125 V AC/DC with a fast-blow response time. The 50 A interrupting capacity at rated voltage means it clears a short-circuit fault up to that level without rupturing the package — adequate for secondary-side protection in low-power AC/DC supplies and DC rails where the available fault current stays under 50 A. Littelfuse lists this part as obsolete. Sourcing runs through independent surplus and broker channels; availability and pricing are confirmed at RFQ against the BOM quantity. Housed in a 2-SMD square end block package measuring 6.10 mm x 2.69 mm x 2.69 mm, the 0451001.MR mounts directly to the PCB footprint for the NANO² 451 series. The 0.153 Ohm DC cold resistance produces an I²R voltage drop of 153 mV at rated current — a factor when the fuse sits in a low-voltage rail where every millivolt of headroom matters. Tape & Reel packaging suits automated pick-and-place assembly. ## Approvals and compliance documentation CSA, PSE, and UL agency approvals are listed — the UL recognition covers the 125 V AC/DC rating and 50 A interrupting capacity for North American panel and equipment builds. PSE certification supports export into the Japanese market. RoHS and REACH compliance documentation is available from the manufacturer's archive for this obsolete part.","metaTitle":"0451001.MR Littelfuse NANO² 451 Fuse, 1A Fast Blow, 125V","metaDescription":"0451001.MR Littelfuse NANO² 451 surface-mount fuse, 1A fast blow, 125V AC/DC, 50A breaking capacity. Obsolete — sourced to order against RFQ.","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":"0.459","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Obsolete","Approval Agency":"CSA, PSE, UL","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":"0.153 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"1 A","Operating Temperature":"-55°C ~ 125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.4600","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/2e33e7b2503f3f5110226be89402b64a.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Where can I buy 0451001.MR and how do I get a price?","answer":"Submit a request with your BOM quantity; current pricing and lot availability are confirmed at quote time."},{"question":"What is the closest pin-compatible alternative to 0451001.MR in this Circuit Protection family?","answer":"A functional replacement requires reviewing the NANO² 451 series parametric range for a 1 A fast-blow SMD fuse with matching footprint and 125 V rating."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0451001.MR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/0451001.MR 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}}