{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SM15T39CAY","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SM15T39CAY","canonicalUrl":"https://icboms.com/stmicroelectronics/SM15T39CAY","factsUrl":"https://icboms.com/api/mcp/products/SM15T39CAY","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SM15T39CAY, Automotive AEC-Q101 TRANSIL™ TVS diode, Zener type, 1500W peak pulse power, 33.3V standoff, 69.7V clamping, bidirectional, DO-214AB SMC package, -40°C to 150°C.","salesMarkdown":"## Transient protection for 33.3 V automotive rails The STMicroelectronics SM15T39CAY is a bidirectional Zener-type TVS diode from the SM15TY TRANSIL™ series, rated for 1500 W peak pulse power (10/1000 µs waveform). It is designed to clamp transients on a 33.3 V nominal rail, with a breakdown voltage range starting at 37.1 V and a maximum clamping voltage of 69.7 V at a peak pulse current of 143 A (8/20 µs). The single bidirectional channel protects against both positive and negative surges in one package, which simplifies layout and saves board space compared to back-to-back unidirectional diodes. The DO-214AB (SMC) surface-mount package provides a standard footprint for reflow assembly and is compatible with high-volume automotive production lines. ## Clamping voltage and pulse current — sizing the protection For a 33.3 V nominal rail, this clamp provides a comfortable margin above the operating voltage while staying below typical 40 V or 60 V semiconductor breakdown thresholds. The 143 A peak pulse current rating (8/20 µs waveform) indicates the diode can handle high-energy transients from inductive loads or battery disconnection without failing short. Because this is a bidirectional device, it clamps both positive and negative surges symmetrically. That eliminates the need for two unidirectional diodes in opposite orientation, reducing component count and board area on dual-polarity or AC-coupled signal lines. ## AEC-Q101 and the automotive supply chain This qualification is a prerequisite for tier-1 automotive suppliers and is often required for any part that goes into safety-related or powertrain ECUs.","metaTitle":"SM15T39CAY TVS Diode, 1500W Bidirectional, AEC-Q101","metaDescription":"STMicroelectronics SM15T39CAY automotive TVS diode, 1500W peak pulse power, 69.7V clamping, AEC-Q101 qualified, DO-214AB SMC package. Available to order.","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, SM15TY, TRANSIL™","Package":"Tape & Reel (TR); Cut Tape (CT)","Applications":"Automotive","Mounting Type":"Surface Mount","Package / Case":"DO-214AB, SMC","Product Status":"Active","lifecycle_stage":"eol_hot","Power - Peak Pulse":"1500W (1.5kW)","Base Product Number":"SM15T39","Operating Temperature":"-40°C~150°C(TJ)","Power Line Protection":"No","Bidirectional Channels":"1","Capacitance @ Frequency":"-","Supplier Device Package":"SMC","Voltage - Breakdown (Min)":"37.1V","Voltage - Clamping (Max) @ Ipp":"69.7V","Voltage - Reverse Standoff (Typ)":"33.3V","Current - Peak Pulse (10/1000µs)":"143A (8/20µs)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$1.3000","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/d3caa9efa0f4fede168088411f4832fd.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SM15T39CAY/alternatives.json"},"ai":{"faq":[{"question":"Where can I buy SM15T39CAY?","answer":"SM15T39CAY is available to order through independent distribution. Contact us for a current price and lead time for your required quantity."},{"question":"Is SM15T39CAY AEC-Q101 qualified?","answer":"Yes, the SM15T39CAY is AEC-Q101 qualified, which means it meets the automotive-grade reliability standards for discrete semiconductors. It is part of the SM15TY TRANSIL™ series from STMicroelectronics."},{"question":"Is SM15T39CAY bidirectional?","answer":"Yes, the SM15T39CAY is a single bidirectional channel device. It clamps both positive and negative transients symmetrically, which is useful for protecting AC-coupled or dual-polarity signal lines."},{"question":"What is the peak pulse power of SM15T39CAY?","answer":"The SM15T39CAY is rated for 1500 W peak pulse power, tested with a 10/1000 µs waveform. This defines its ability to absorb high-energy transients without damage."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SM15T39CAY","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SM15T39CAY 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}}