{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"045101.6MRL","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"045101.6MRL","canonicalUrl":"https://icboms.com/littelfuse-inc/045101.6MRL","factsUrl":"https://icboms.com/api/mcp/products/045101.6MRL","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. NANO²® 451 series, Board Mount (Cartridge Style Excluded) fuse, 045101.6MRL, 1.6 A, 125 VAC/VDC, Fast Blow, 50 A breaking capacity, 2-SMD Square End Block package, Tape & Reel.","salesMarkdown":"## Board-level overcurrent protection for 1.6 A rails The Littelfuse 045101.6MRL is a NANO² 451 series surface-mount fuse rated 1.6 A at 125 VAC and 125 VDC, fast-blow response. It protects a 1.6 A load circuit — think a 24 VDC sensor bank, a 5 V logic rail, or a 12 V auxiliary supply on a control board — where the fuse must clear before the downstream regulator or connector exceeds its thermal limit. The 50 A breaking capacity at rated voltage means it safely interrupts a fault current up to that level without rupturing the package or sustaining an arc — sufficient for most secondary-side DC rails and low-power AC branch circuits where the prospective short-circuit current stays under 50 A. ## What the ratings mean for the BOM line The 1.6 A current rating is the continuous current the fuse carries at 25°C ambient without opening. For a 1.6 A load, the fuse operates below its nominal rating with margin; for a 1.5 A load, it sits at 94% of rating — within the typical derating guideline of 75-80% for elevated ambient. The fast-blow characteristic means it opens quickly on a moderate overcurrent, protecting semiconductor junctions that cannot tolerate sustained overload. Melting I²t of 1.06 A²s is the energy required to melt the fuse element. This number governs inrush withstand: a capacitor bank charging through this fuse must stay below 1.06 A²s total energy, or the fuse opens on start-up. It also coordinates with downstream semiconductor fuses or PTCs — the 045101.6MRL should clear before a 2 A fast-blow in series, given the I²t ratio. DC cold resistance of 0.058 Ohms at 25°C produces a voltage drop of 93 mV at rated current — negligible for a 5 V or 12 V rail, but worth checking if the load is a 1.6 A, 1.8 V FPGA core where every millivolt of IR drop matters. The 2-SMD square end block package measures 6.10 mm long by 2.69 mm wide and 2.69 mm tall — a compact footprint for dense PCB layouts. The square end terminals are soldered to pads on both ends; the fuse body sits above the board, so the solder fillet is visible for AOI inspection. Supplied in Tape & Reel (TR) or Cut Tape (CT) — the TR option suits automated pick-and-place for volume production; CT works for prototype or low-volume builds. ## Compliance and sourcing posture The 045101.6MRL carries CSA, PSE, and UL approvals — accepted in North American, Japanese, and many international regulatory frameworks. UL recognition means the fuse is listed to UL 248-14, the standard for supplementary fuses used in equipment not intended for branch-circuit protection.","metaTitle":"Littelfuse 045101.6MRL NANO² 451 Fuse, 1.6 A, 125 V","metaDescription":"Littelfuse 045101.6MRL NANO² 451 surface-mount fuse, 1.6 A, 125 VAC/VDC, fast blow, 50 A breaking capacity. Active production, UL/CSA/PSE approved.","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); Cut Tape (CT)","Fuse Type":"Board Mount (Cartridge Style Excluded)","Melting I²t":"1.06","Mounting Type":"Surface Mount","Response Time":"Fast Blow","Package / Case":"2-SMD, Square End Block","Product Status":"Active","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":"0.058 Ohms","Voltage Rating - AC":"125 V","Voltage Rating - DC":"125 V","Current Rating (Amps)":"1.6 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/604a0e4c498aa97d2607992508357d04.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Where can I buy 045101.6MRL and how is it quoted?","answer":"Submit an RFQ for the specific volume and packaging (Tape & Reel or Cut Tape)."},{"question":"What is the breaking capacity of 045101.6MRL and why does it matter?","answer":"The breaking capacity is 50 A at the rated voltage of 125 VAC/125 VDC. This is the maximum fault current the fuse can safely interrupt without rupturing. For a secondary-side DC rail fed from a 100 W supply, the prospective short-circuit current is typically well below 50 A, so this fuse clears safely. For a higher-capacity bus, verify the available fault current stays under 50 A."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/045101.6MRL","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/045101.6MRL 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}}