{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SM4T56AY","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SM4T56AY","canonicalUrl":"https://icboms.com/stmicroelectronics/SM4T56AY","factsUrl":"https://icboms.com/api/mcp/products/SM4T56AY","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SM4T56AY, Automotive AEC-Q101 Zener TVS, 48V standoff, 53.3V breakdown, 100V clamping, 400W peak pulse power, 1 unidirectional channel, DO-214AC SMA package, -55°C to 150°C.","salesMarkdown":"## 48V rail protection with AEC-Q101 pedigree Its 53.3V minimum breakdown voltage and 100V maximum clamping voltage at the peak pulse current define the protection window for downstream electronics in engine control units, transmission controllers, and body modules. The single unidirectional channel in a DO-214AC (SMA) surface-mount package keeps the bill of materials compact for per-rail clamping. ## What the 400W rating means for your BOM For a 48V system — common in mild-hybrid and 48V auxiliary loads — the 23A peak pulse current (8/20µs waveform) gives enough headroom for load-dump and inductive kickback events typical in automotive environments. If your circuit sees repetitive surges near the rated limit, derate the junction temperature from the -55°C to 150°C operating range; the thermal impedance of the SMA pad on a standard 1 oz copper footprint is what governs real-world dissipation. ## AEC-Q101 qualification — not just a sticker The TRANSIL™ series designation from STMicroelectronics confirms the die construction is optimized for fast clamping response, which matters when the protection must fire before the downstream IC sees the overvoltage. The base product number SM4T56 covers the whole family, so if you need a different voltage variant in the same footprint and qualification, the rest of the SM4TY series is a direct drop-in.","metaTitle":"STMicroelectronics SM4T56AY Zener TVS, 400W, AEC-Q101, SMA","metaDescription":"STMicroelectronics SM4T56AY automotive AEC-Q101 Zener TVS diode. 48V standoff, 53.3V breakdown, 100V clamping, 400W peak pulse power.","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":"SM4T56","Operating Temperature":"-55°C~150°C(TJ)","Power Line Protection":"No","Capacitance @ Frequency":"-","Supplier Device Package":"SMA (DO-214AC)","Unidirectional Channels":"1","Voltage - Breakdown (Min)":"53.3V","Voltage - Clamping (Max) @ Ipp":"100V","Voltage - Reverse Standoff (Typ)":"48V","Current - Peak Pulse (10/1000µs)":"23A (8/20µs)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.9400","stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/45721247f0377ca5ff3983c35eddc2fa.pdf","sourceUrl":null},"ai":{"faq":[{"question":"Is SM4T56AY automotive qualified?","answer":"Yes, the SM4T56AY is AEC-Q101 qualified, part of the Automotive SM4TY series. It is suitable for use in automotive electronics requiring the stress-test validation that qualification provides."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SM4T56AY","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SM4T56AY 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}}