{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SM4T50CAY","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SM4T50CAY","canonicalUrl":"https://icboms.com/stmicroelectronics/SM4T50CAY","factsUrl":"https://icboms.com/api/mcp/products/SM4T50CAY","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SM4T50CAY, Automotive AEC-Q101, SM4TY, TRANSIL™, Zener, 400W peak pulse, 43V reverse standoff, 91V clamping, 25A (8/20µs), DO-214AC SMA, -55°C~150°C.","salesMarkdown":"## What the 400W peak pulse rating means for your automotive ECU It clamps transients on 43V nominal rails (reverse standoff) to 91V maximum, absorbing 400W of peak pulse power per the 10/1000µs waveform. The 25A peak pulse current rating (8/20µs) covers ISO 7637-2 pulses common in 24V truck and 12V passenger-car ECUs. ## Breakdown, clamping, and standoff — the three numbers that decide fit Minimum breakdown voltage is 47.8V, so the device starts conducting around 48V. The 43V reverse standoff voltage is the DC rail level the TVS leaves untouched during normal operation — a 48V nominal bus would be too close; this is sized for 24V or 12V systems where the steady-state rail stays well below 43V. Maximum clamping at peak pulse current is 91V, which sets the voltage stress the downstream silicon must survive. For a 24V truck ECU with a 60V-rated input cap, the 91V clamp is within the margin if the TVS is placed directly at the connector. The TRANSIL series designation is ST's own process for planar passivated junctions, giving stable leakage over temperature. The base product number SM4T50 covers unidirectional and bidirectional variants in the same SMA footprint, simplifying alternate-source qualification if needed.","metaTitle":"STMicroelectronics SM4T50CAY TVS Diode, 400W, AEC-Q101","metaDescription":"STMicroelectronics SM4T50CAY bidirectional Zener TVS, 400W peak pulse power, 43V standoff, 91V clamping, AEC-Q101 qualified, -55°C to 150°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"STMicroelectronics","Type":"Zener","Series":"Automotive, AEC-Q101, SM4TY, TRANSIL™","Package":"Tape & Reel (TR); Cut Tape (CT)","Applications":"Automotive","Mounting Type":"Surface Mount","Package / Case":"DO-214AC, SMA","Product Status":"Active","lifecycle_stage":"eol_hot","Power - Peak Pulse":"400W","Base Product Number":"SM4T50","Operating Temperature":"-55°C~150°C(TJ)","Power Line Protection":"No","Bidirectional Channels":"1","Capacitance @ Frequency":"-","Supplier Device Package":"SMA (DO-214AC)","Voltage - Breakdown (Min)":"47.8V","Voltage - Clamping (Max) @ Ipp":"91V","Voltage - Reverse Standoff (Typ)":"43V","Current - Peak Pulse (10/1000µs)":"25A (8/20µs)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.6000","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/45721247f0377ca5ff3983c35eddc2fa.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Does SM4T50CAY meet AEC-Q101 qualification?","answer":"Yes, the SM4T50CAY is part of the Automotive AEC-Q101 qualified SM4TY series, making it suitable for automotive-grade applications."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SM4T50CAY","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SM4T50CAY 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}}