{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"0451.375MRSN","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"0451.375MRSN","canonicalUrl":"https://icboms.com/littelfuse-inc/0451.375MRSN","factsUrl":"https://icboms.com/api/mcp/products/0451.375MRSN","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. NANO²® 451 series, Board Mount Surface Mount Fuse, 375 mA, 125 V AC, Fast Blow, 50 A breaking capacity, 2-SMD Square End Block package, Tape & Reel.","salesMarkdown":"## 375 mA fast-blow for sensitive board-level protection The Littelfuse 0451.375MRSN is a 375 mA, 125 V AC fast-blow surface-mount fuse from the NANO²® 451 series. Its 50 A interrupting rating at rated voltage means it can safely clear a fault up to that current without rupturing the package — critical for protecting downstream silicon in a power supply or control circuit. ## Melting I²t and cold resistance for coordination With a melting I²t of 0.0425, this fuse coordinates with semiconductor junctions and PCB traces that have a lower I²t withstand — the fuse opens before the downstream component exceeds its thermal limit. The 0.61 Ω DC cold resistance means the voltage drop at rated current is about 229 mV, negligible in a 125 V circuit but worth checking in a low-voltage rail. The fast-blow response time suits circuits with inrush-sensitive loads such as relays, solenoids, or capacitive inputs where a time-delay fuse would pass the surge but a fast-blow clears before damage occurs. ## Surface-mount package and environmental range CSA and UR approval agency marks confirm acceptance for North American and Canadian equipment — a requirement for UL 508A industrial control panels and similar listings.","metaTitle":"Littelfuse 0451.375MRSN NANO² 451 Fuse, 375 mA, 125 V","metaDescription":"Littelfuse 0451.375MRSN NANO²® 451 surface-mount fuse, 375 mA, 125 V AC, fast-blow, 50 A breaking capacity. Active production, CSA/UR approved. Request a quote.","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":"0.0425","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":"0.61 Ohms","Voltage Rating - AC":"125 V","Current Rating (Amps)":"375 mA","Operating Temperature":"-55°C~125°C","Breaking Capacity @ Rated Voltage":"50A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.4469","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/604a0e4c498aa97d2607992508357d04.pdf","sourceUrl":null},"ai":{"faq":[{"question":"How can I get pricing and availability for 0451.375MRSN?","answer":"Submit an RFQ through this listing."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/0451.375MRSN","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/0451.375MRSN 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}}