{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SM4T28CAY","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SM4T28CAY","canonicalUrl":"https://icboms.com/stmicroelectronics/SM4T28CAY","factsUrl":"https://icboms.com/api/mcp/products/SM4T28CAY","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SM4T28CAY, Automotive Grade Zener TVS Diode, Bidirectional, 400W Peak Pulse Power, 24V Reverse Standoff, 26.7V Breakdown Min, 50V Clamping, DO-214AC (SMA), AEC-Q101 Qualified.","salesMarkdown":"## 26.7V breakdown — the clamp threshold for 24V rails Its 24V reverse standoff voltage matches a nominal 24V supply rail, with a minimum breakdown of 26.7V and a maximum clamping voltage of 50V at the peak pulse current of 46A (8/20µs). The 400W rating means this part can absorb substantial transient energy without failing — relevant for load-dump and inductive-switch-off events in automotive and industrial 24V systems. ## AEC-Q101 — the automotive-grade gate","metaTitle":"STMicroelectronics SM4T28CAY TVS Diode, 400W Bidirectional","metaDescription":"STMicroelectronics SM4T28CAY automotive TVS diode in SMA package. 400W peak pulse power, 24V standoff, 26.7V breakdown, AEC-Q101 qualified.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"STMicroelectronics","Type":"Zener","Grade":"Automotive","Series":"*","Package":"Tape & Reel (TR) Cut Tape (CT)","Applications":"-","Mounting Type":"Surface Mount","Qualification":"AEC-Q101","Package / Case":"DO-214AC, SMA","Product Status":"Active","lifecycle_stage":"eol_hot","Power - Peak Pulse":"400W","Base Product Number":"SM4T28","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)":"26.7V","Voltage - Clamping (Max) @ Ipp":"50V","Voltage - Reverse Standoff (Typ)":"24V","Current - Peak Pulse (10/1000µs)":"46A (8/20µs)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9300","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/45721247f0377ca5ff3983c35eddc2fa.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SM4T28CAY/alternatives.json"},"ai":{"faq":[{"question":"Is SM4T28CAY AEC-Q101 qualified?","answer":"Yes, the SM4T28CAY is AEC-Q101 qualified, which is the automotive-grade stress-test standard for discrete semiconductors. This qualification covers the part for use in automotive ECUs, sensors, and power distribution modules."},{"question":"Can SM4T28CAY replace SM4T28A?","answer":"The SM4T28CAY is the bidirectional variant of the SM4T28A unidirectional part. Both share the same breakdown and clamping voltages, but the CA version clamps both polarities, while the A version protects only one. If the circuit already has a bridge rectifier or the line is DC-only, the unidirectional SM4T28A may be sufficient; for AC or floating lines, the bidirectional SM4T28CAY is the correct choice. The package (SMA) and footprint are identical."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SM4T28CAY","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SM4T28CAY 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}}