{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"045101.5MRSN","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"045101.5MRSN","canonicalUrl":"https://icboms.com/littelfuse-inc/045101.5MRSN","factsUrl":"https://icboms.com/api/mcp/products/045101.5MRSN","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 Series, Board Mount SMD Fast Blow Fuse, 045101.5MRSN, 1.5 A, 125 VAC, 50 A Breaking Capacity, 2-SMD Square End Block Package, Tape & Reel.","salesMarkdown":"## 1.5 A fast-blow SMD fuse for secondary-side protection The Littelfuse 045101.5MRSN is a 1.5 A, 125 VAC fast-blow fuse in the NANO² 451 series, housed in a 2-SMD square end block package for surface-mount assembly. Rated breaking capacity is 50 A at the rated voltage — sufficient to clear a hard short on a secondary-side DC rail or low-power AC branch without rupturing the package. The 0.853 melting I²t means it tolerates brief inrush pulses from a downstream capacitor bank or a small motor start without nuisance opening, while still blowing fast on a sustained overcurrent. ## What the ratings mean for the BOM line The 125 VAC rating covers most single-phase control-voltage rails (120 VAC nominal) and the DC cold resistance of 0.063 Ohms keeps the voltage drop under 100 mV at rated current. The 2-SMD square end block measures 6.10 mm x 2.69 mm x 2.69 mm — a compact footprint that mates with standard wave-solder or reflow profiles for the NANO² 451 series. Supplied on Tape & Reel (TR), it feeds directly into a pick-and-place machine; the reel quantity matches the standard production batch for a mid-volume BOM line. Carries CSA and UR approvals, meaning it is accepted for use in equipment sold into North American markets under those safety standards.","metaTitle":"045101.5MRSN Littelfuse NANO² 451 SMD Fuse, 1.5 A, 125 V","metaDescription":"045101.5MRSN Littelfuse NANO² 451 fast-blow SMD fuse, 1.5 A, 125 VAC, 50 A breaking capacity. Active production. CSA, UR approved. Order against RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"Littelfuse Inc.","Color":"-","Series":"NANO²® 451","Package":"Tape & Reel (TR)","Fuse Type":"Board Mount (Cartridge Style Excluded)","Melting I²t":"0.853","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Active","Approval Agency":"CSA, UR","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":"0.063 Ohms","Voltage Rating - AC":"125 V","Current Rating (Amps)":"1.5 A","Operating Temperature":"-55°C ~ 125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.4614","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/604a0e4c498aa97d2607992508357d04.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the breaking capacity of the 045101.5MRSN?","answer":"The 045101.5MRSN has a breaking capacity of 50 A at its rated voltage of 125 VAC, which is sufficient to safely interrupt a hard short on a secondary-side circuit."},{"question":"What approvals does the 045101.5MRSN carry?","answer":"The 045101.5MRSN carries CSA and UR approvals, qualifying it for use in equipment sold into North American markets under those safety standards."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/045101.5MRSN","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/045101.5MRSN when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}