{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"045101.5MR","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"045101.5MR","canonicalUrl":"https://icboms.com/littelfuse-inc/045101.5MR","factsUrl":"https://icboms.com/api/mcp/products/045101.5MR","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse NANO²® 451 series, Board Mount (Cartridge Style Excluded) SMD fuse, 045101.5MR, 1.5 A, 125 V AC/DC, Fast Blow, 50 A breaking capacity, 2-SMD square end block package.","salesMarkdown":"## 1.5 A fast-blow — what the ratings mean for fit The 045101.5MR: Rated 1.5 A continuous at both 125 V AC and 125 V DC — the same voltage ceiling on both sides means it handles AC or DC rails without derating the voltage spec. Fast-blow response time: the fuse element opens quickly on overcurrent, protecting sensitive semiconductor loads where a time-delay fuse would let the fault energy pass through. Breaking capacity of 50 A at rated voltage — this is the maximum fault current the fuse can safely interrupt without rupturing. For a 1.5 A rail, 50 A interrupting rating covers most secondary-side faults in low-power supplies. ## Melting I²t and cold resistance Melting I²t of 0.853 A²s — this is the energy needed to melt the fuse element. It tells you whether the fuse holds through inrush from a capacitive input filter or a motor start. For a 1.5 A fast-blow, 0.853 is low; expect it to open on moderate inrush unless the pulse energy stays well below that threshold. ## SMD footprint and approvals 2-SMD square end block package, surface-mount — the 0.240\" x 0.106\" x 0.106\" footprint is common for NANO² fuses and fits standard pick-and-place reflow assembly. Approved by CSA, PSE, and UL — these agency marks cover North American and Japanese safety standards, so the fuse is accepted in equipment sold into those markets without additional component-level certification.","metaTitle":"Littelfuse 045101.5MR NANO² 451 Fuse, 1.5 A, 125 V, Obsolete","metaDescription":"Littelfuse 045101.5MR NANO²® 451 fast-blow SMD fuse, 1.5 A, 125 V AC/DC, 50 A 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":"0.853","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":"0.063 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"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":"$1.4600","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/2e33e7b2503f3f5110226be89402b64a.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the breaking capacity of the 045101.5MR?","answer":"50 A at the rated voltage — the fuse safely interrupts fault currents up to 50 A without rupturing."},{"question":"What approvals does the 045101.5MR carry?","answer":"CSA, PSE, and UL — covering North American and Japanese safety standards for component-level circuit protection."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/045101.5MR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/045101.5MR 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}}