{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SMBJ40A-TR","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SMBJ40A-TR","canonicalUrl":"https://icboms.com/stmicroelectronics/SMBJ40A-TR","factsUrl":"https://icboms.com/api/mcp/products/SMBJ40A-TR","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SMBJ, TRANSIL™, TVS Zener, Unidirectional, 40V Reverse Standoff, 64.5V Clamping, 600W Peak Pulse Power, DO-214AA SMB, Surface Mount, -55°C to 150°C.","salesMarkdown":"## 40V rail protector in a DO-214AA SMB package Its 40V reverse standoff voltage means the diode stays off below that level, so it won't leak or conduct during normal operation on a 40V bus. When a surge hits, it clamps at a maximum 64.5V — that is the peak voltage the downstream circuitry must survive. The 600W peak pulse power rating (10/1000µs waveform) tells you how much transient energy it can absorb in a single event; for higher-energy surges you step up to the SMCJ or 1.5KE series. ## Clamping voltage and standoff — the two numbers that matter When you spec a TVS for a 40V rail, the standoff voltage is the first check: it must be at or above the maximum DC operating voltage so the diode does not conduct during normal bias. The clamping voltage is the second: every component on that rail must be rated to survive 64.5V for the duration of the transient. If your downstream parts are 60V-rated, this clamp leaves only 4.5V of headroom — consider a lower-clamping TVS or a higher-voltage downstream rating. The 9.7A peak pulse current (10/1000µs) is the current that flows at the clamping voltage; verify your PCB trace width and via count can handle that pulse without fusing. ## Active and available — no LTB pressure","metaTitle":"STMicroelectronics SMBJ40A-TR TVS Diode, 40V Standoff","metaDescription":"STMicroelectronics SMBJ40A-TR TRANSIL™ TVS diode, 40V reverse standoff, 64.5V clamping, 600W peak pulse power, DO-214AA package.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"STMicroelectronics","Type":"Zener","Series":"SMBJ, TRANSIL™","Package":"Tape & Reel (TR) Cut Tape (CT)","Applications":"General Purpose","Mounting Type":"Surface Mount","Package / Case":"DO-214AA, SMB","Product Status":"Active","lifecycle_stage":"eol_hot","Power - Peak Pulse":"600W","Base Product Number":"SMBJ40","Operating Temperature":"-55°C ~ 150°C (TJ)","Power Line Protection":"No","Capacitance @ Frequency":"-","Supplier Device Package":"SMB (DO-214AA)","Unidirectional Channels":"1","Voltage - Breakdown (Min)":"44.4V","Voltage - Clamping (Max) @ Ipp":"64.5V","Voltage - Reverse Standoff (Typ)":"40V","Current - Peak Pulse (10/1000µs)":"9.7A"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.4500","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/28916e022258112f057e7568b7920d5a.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SMBJ40A-TR/alternatives.json"},"ai":{"faq":[],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SMBJ40A-TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SMBJ40A-TR 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}}