{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SM4T23CAY","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SM4T23CAY","canonicalUrl":"https://icboms.com/stmicroelectronics/SM4T23CAY","factsUrl":"https://icboms.com/api/mcp/products/SM4T23CAY","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SM4T23CAY, Automotive AEC-Q101 TRANSIL™ TVS, 400W peak pulse power, 20V reverse standoff, bidirectional, DO-214AC SMA package.","salesMarkdown":"## 400 W bidirectional TVS for 20 V automotive rails The STMicroelectronics SM4T23CAY is a bidirectional Zener-based transient voltage suppressor from the TRANSIL™ family, purpose-built for automotive electronics. The part clamps at 42.8 V maximum on a 54 A peak pulse current (8/20 µs waveform), which keeps the downstream silicon inside its safe operating area during a 400 W surge event. The reverse standoff voltage is 20 V, so it sits across a nominal 12 V rail without conducting leakage, but begins to break down at 22.2 V minimum — a tight tolerance that leaves margin for the regulator's output. The 20 V reverse standoff voltage is the DC or peak-AC voltage the part can withstand without conducting appreciable current. Below that, it looks like an open circuit. The minimum breakdown voltage of 22.2 V is where avalanche conduction starts — the point at which the TVS begins to shunt current. For a 12 V automotive rail that can transiently rise to 30 V or more during a load dump, the 42.8 V clamp keeps the downstream 40 V-rated MOSFETs or 36 V-rated ICs out of avalanche. The 400 W peak pulse power rating (8/20 µs) is the energy-handling capability for a single pulse; repetitive events need derating per the datasheet's pulse-derating curve. Housed in a DO-214AC (SMA) package, the SM4T23CAY is a surface-mount device with a small footprint — roughly 4.5 mm by 2.8 mm body. The operating junction temperature range is -55°C to 150°C, covering the full automotive temperature envelope from cold-crank at -40°C to under-hood ambient near 125°C. No power line protection (the part is unidirectional in function, but bidirectional in pinout — it clamps both polarities equally). It is AEC-Q101 qualified, which means the part has been through the full automotive qualification flow — high-temperature reverse bias, temperature cycling, and humidity testing. RoHS compliance is standard for ST's TRANSIL™ family; no lead or restricted substances in the termination finish. For volume production, the part can be dual-sourced with other AEC-Q101 SMA-packaged 20 V bidirectional TVS diodes from Littelfuse or Onsemi, though the exact breakdown and clamping limits should be verified against the application's surge profile.","metaTitle":"STMicroelectronics SM4T23CAY TVS Diode, 400W, AEC-Q101, SMA","metaDescription":"STMicroelectronics SM4T23CAY is a 400W bidirectional TVS diode, AEC-Q101 qualified for automotive use. 20V working voltage, 22.2V breakdown, 42.8V clamping.","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":"SM4T23","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)":"22.2V","Voltage - Clamping (Max) @ Ipp":"42.8V","Voltage - Reverse Standoff (Typ)":"20V","Current - Peak Pulse (10/1000µs)":"54A (8/20µs)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9300","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/45721247f0377ca5ff3983c35eddc2fa.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is SM4T23CAY AEC-Q101 qualified?","answer":"Yes, the SM4T23CAY is AEC-Q101 qualified, making it suitable for automotive applications that require the part to pass the stress tests defined by the Automotive Electronics Council."},{"question":"What is the closest equivalent to SM4T23CAY?","answer":"A standard SMAJ23A is a 400 W, 23 V unidirectional TVS in the same DO-214AC package, but it is not AEC-Q101 qualified and is unidirectional. The SM4T23CAY is bidirectional and automotive-grade. For a pin-compatible AEC-Q101 alternative, look at the Littelfuse SMAJ20A-Q or Onsemi SZ1SMA20AT3G — both are 20 V standoff, 400 W, SMA-packaged, and AEC-Q101, though verify the breakdown and clamping limits against your surge requirement."},{"question":"Is SM4T23CAY RoHS compliant?","answer":"Yes, as part of ST's TRANSIL™ family, the SM4T23CAY is RoHS compliant. The termination finish is matte tin, free of lead and other restricted substances."},{"question":"What is the lead time for SM4T23CAY from distributors?","answer":"Lead time is confirmed at quote time based on current factory backlog and independent stock availability. Submit an RFQ for your target quantity and we will provide a firm lead time."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SM4T23CAY","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SM4T23CAY 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}}