{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SM6T18CAY","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SM6T18CAY","canonicalUrl":"https://icboms.com/stmicroelectronics/SM6T18CAY","factsUrl":"https://icboms.com/api/mcp/products/SM6T18CAY","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SM6T18CAY, Automotive AEC-Q101 TRANSIL™ TVS diode, bidirectional, 600W peak pulse power, 15.3V standoff voltage, 32.5V clamping, DO-214AA SMB package.","salesMarkdown":"## What this TVS diode protects and where it goes The STMicroelectronics SM6T18CAY is a bidirectional Zener-type transient voltage suppression diode from the SM6TY TRANSIL™ series, rated for 600 W peak pulse power (10/1000 µs waveform). It is designed to clamp fast overvoltage transients on 12 V automotive power rails and signal lines, with a reverse standoff voltage of 15.3 V and a maximum clamping voltage of 32.5 V at the peak pulse current. Typical applications include load-dump protection, inductive-load switching suppression, and ESD protection on CAN/LIN bus interfaces in engine control units, body controllers, and infotainment systems. ## 600 W peak pulse — what it takes to kill a transient The 600 W rating is the peak pulse power the device can absorb for a standard 10/1000 µs surge without failing. For an 8/20 µs waveform (the typical ESD or lightning-induced transient), the peak pulse current is rated at 123 A. That means this diode can shunt a substantial surge — enough to protect a 12 V ECU input from a load-dump event or a direct battery-line transient. The 15.3 V standoff voltage means it sits across the rail without conducting during normal operation, even with a 12 V battery charging at 14.4 V. The 17.1 V minimum breakdown voltage gives the headroom to avoid nuisance triggering from ripple or alternator noise. ## AEC-Q101 — the automotive gate The SM6T18CAY carries AEC-Q101 qualification, which is the stress-test and quality baseline for discrete semiconductors used in automotive applications. This means it has passed accelerated life tests including high-temperature reverse bias, temperature cycling, and humidity bias — the kind of validation a non-automotive SM6T18 part has not undergone. For a BOM destined for a production vehicle or a heavy-equipment controller, this qualification is often a non-negotiable requirement. ## Package and footprint — SMB (DO-214AA) The SM6T18CAY is supplied in the DO-214AA (SMB) surface-mount package, a common footprint for 600 W-class TVS diodes. The SMB package has a standard land pattern that matches many other 600 W TVS diodes from different manufacturers, so the PCB layout is straightforward if you need to qualify an alternate source.","metaTitle":"SM6T18CAY Automotive TVS Diode, 600W, 15.3V Standoff","metaDescription":"STMicroelectronics SM6T18CAY bidirectional TVS diode, 600W peak pulse power, 15.3V standoff, 32.5V clamp. AEC-Q101 qualified for automotive systems.","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, SM6TY, TRANSIL™","Package":"Tape & Reel (TR); Cut Tape (CT)","Applications":"Automotive","Mounting Type":"Surface Mount","Package / Case":"DO-214AA, SMB","Product Status":"Active","lifecycle_stage":"eol_hot","Power - Peak Pulse":"600W","Base Product Number":"SM6T18","Operating Temperature":"-55°C~150°C(TJ)","Power Line Protection":"No","Bidirectional Channels":"1","Capacitance @ Frequency":"-","Supplier Device Package":"SMB (DO-214AA)","Voltage - Breakdown (Min)":"17.1V","Voltage - Clamping (Max) @ Ipp":"32.5V","Voltage - Reverse Standoff (Typ)":"15.3V","Current - Peak Pulse (10/1000µs)":"123A (8/20µs)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.1700","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/3a95ac6513bab2f04fd61565540cbe6f.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SM6T18CAY/alternatives.json"},"ai":{"faq":[{"question":"Is SM6T18CAY suitable for 12V automotive systems?","answer":"Yes. The 15.3 V reverse standoff voltage means the diode does not conduct during normal 12 V system operation, even with the battery charging at 14.4 V. The 17.1 V minimum breakdown voltage provides margin above the nominal rail, so it will not trigger on normal ripple or alternator noise. The 32.5 V clamping voltage limits the transient to a level that downstream components rated for 40 V or higher can survive."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SM6T18CAY","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SM6T18CAY 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}}