{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SM4T56CAY","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SM4T56CAY","canonicalUrl":"https://icboms.com/stmicroelectronics/SM4T56CAY","factsUrl":"https://icboms.com/api/mcp/products/SM4T56CAY","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SM4T56CAY, Automotive Grade, Zener, Bidirectional TVS Diode, 400W Peak Pulse Power, 48V Reverse Standoff, 53.3V Breakdown, 100V Clamping, DO-214AC (SMA), AEC-Q101, -55°C to 150°C.","salesMarkdown":"## What this TVS diode protects and where The STMicroelectronics SM4T56CAY is a bidirectional Zener-type TVS diode in the DO-214AC (SMA) package, AEC-Q101 qualified for automotive applications. The bidirectional configuration means it can clamp both positive and negative transients, which is useful on AC-coupled signal lines or power rails where polarity reversal is a concern. ## 400 W peak pulse — what it buys you For a 48 V rail, a 400 W part can absorb a transient current of roughly 4 A before the clamping voltage hits 100 V, which is typical for load-dump or inductive-load switching in a 12 V or 24 V automotive system that has a DC-DC converter stepping up to 48 V. The 23 A peak pulse current rating (8/20 µs) reflects a faster, higher-current transient like an ESD event. This part is not intended for continuous overvoltage — the power line protection flag is 'No' — so it should be placed after the main fuse and input filter, not as a crowbar. ## AEC-Q101: what the auditor sees For an OEM auditor reviewing a PPAP, the AEC-Q101 report and the 150°C Tj rating are the documentation hooks that confirm this part is qualified for the application, not just 'capable'. The active lifecycle status means there is no imminent EOL notice;. ## DO-214AC (SMA) — footprint and assembly The SM4T56CAY is supplied in the DO-214AC (SMA) package, a standard surface-mount footprint for TVS diodes up to 600 W. The SMA package is small enough for dense PCB layouts yet large enough for manual or automated soldering. The tape-and-reel and cut-tape options accommodate both high-volume pick-and-place and prototype builds. The part is RoHS compliant, which is a standard requirement for automotive builds under EU directives.","metaTitle":"SM4T56CAY STMicroelectronics TVS Diode, 400W Bidirectional","metaDescription":"STMicroelectronics SM4T56CAY automotive-grade bidirectional TVS diode, 400W peak pulse power, 48V standoff, AEC-Q101 qualified. Available to order.","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":"SM4T56","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)":"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":"$0.9300","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/45721247f0377ca5ff3983c35eddc2fa.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SM4T56CAY/alternatives.json"},"ai":{"faq":[{"question":"Is SM4T56CAY bidirectional?","answer":"Yes, it is a single-channel bidirectional TVS diode, meaning it clamps transients of both polarities."},{"question":"Is SM4T56CAY RoHS compliant?","answer":"Yes, the part is RoHS compliant."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SM4T56CAY","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SM4T56CAY 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}}