{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"1.5KE43-B","brand":"Littelfuse Inc.","brandSlug":"littelfuse-inc","productSlug":"1.5KE43-B","canonicalUrl":"https://icboms.com/littelfuse-inc/1.5KE43-B","factsUrl":"https://icboms.com/api/mcp/products/1.5KE43-B","rawCanonicalId":null},"summary":{"shortDescription":"Littelfuse Inc. 1.5KE Series Zener TVS diode, 1.5KE43-B, 1500W peak pulse, 36.8V reverse standoff, 62.27V clamping, DO-201AA axial, bulk.","salesMarkdown":"## What the 1500W rating means for your rail The 1.5KE43-B is a 1500W (1.5kW) peak pulse power TVS diode in the 1.5KE series from Littelfuse — a Zener-type unidirectional transient suppressor designed to clamp voltage spikes on a DC rail. The 1500W rating is the device's ability to absorb a single 10/1000µs pulse without failing — not continuous power. For repetitive surges, derate per the datasheet's pulse derating curve. The unidirectional channel (1) means it clamps only one polarity; for AC lines or bidirectional protection you need the bidirectional variant in the same family. Through-hole DO-201AA (DO-27 axial) package — the body is 9.1 mm long with 0.96 mm diameter leads, standard for 1.5 kW TVS diodes. The bulk packaging means loose tubes or bag, not tape-and-reel. Lead forming for PCB insertion is straightforward; the axial leads suit point-to-point wiring or through-hole boards with 0.100-inch pitch spacing. The junction temp rating is the absolute limit; derate power above 25°C per the manufacturer's curve. ## Lifecycle reality — obsolete, sourced through surplus For a BOM line that calls out the 1.5KE43-B, the functional replacement is another 1500W unidirectional TVS with 36.8V standoff in DO-201 — but the exact clamping voltage and breakdown tolerance may shift. Pin-compatible alternatives exist within the 1.5KE series (e.g., 1.5KE43A for tighter tolerance), but no direct cross-reference is published. Confirm the protection window against the original design's transient requirements before substituting.","metaTitle":"1.5KE43-B Littelfuse TVS Diode, 1500W, DO-201","metaDescription":"Littelfuse 1.5KE43-B Zener TVS diode, 1500W peak pulse, 36.8V standoff, DO-201 axial. Obsolete — sourced to order via independent distribution. Request RFQ.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"Littelfuse Inc.","Type":"Zener","Series":"1.5KE","Package":"Bulk","Applications":"General Purpose","Mounting Type":"Through Hole","Package / Case":"DO-201AA, DO-27, Axial","Product Status":"Obsolete","lifecycle_stage":"unknown","Power - Peak Pulse":"1500W (1.5kW)","Base Product Number":"1.5KE","Operating Temperature":"-55°C ~ 175°C (TJ)","Power Line Protection":"No","Capacitance @ Frequency":"-","Supplier Device Package":"DO-201","Unidirectional Channels":"1","Voltage - Breakdown (Min)":"38.75V","Voltage - Clamping (Max) @ Ipp":"62.27V","Voltage - Reverse Standoff (Typ)":"36.8V","Current - Peak Pulse (10/1000µs)":"25.6A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/149eca2cbf10498ecc0c7eab912fe9f4.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the closest pin-compatible alternative to 1.5KE43-B in the 1.5KE family?","answer":"The 1.5KE43A (bidirectional) or 1.5KE43CA (bidirectional) share the same DO-201 package and 1500W power rating. The 1.5KE43-B is unidirectional; the A suffix parts have tighter breakdown tolerance (±5% vs ±10%). Verify the polarity and clamping voltage before substituting."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/littelfuse-inc/1.5KE43-B","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/littelfuse-inc/1.5KE43-B 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}}