{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"SMAJ28CA-TR","brand":"STMicroelectronics","brandSlug":"stmicroelectronics","productSlug":"SMAJ28CA-TR","canonicalUrl":"https://icboms.com/stmicroelectronics/SMAJ28CA-TR","factsUrl":"https://icboms.com/api/mcp/products/SMAJ28CA-TR","rawCanonicalId":null},"summary":{"shortDescription":"STMicroelectronics SMAJ28CA-TR, TRANSIL™ series, Bidirectional TVS Diode, 400W peak pulse power, 28V reverse standoff, 31.1V breakdown, 59V clamping, DO-214AC SMA package, -55°C to 150°C.","salesMarkdown":"## What this TVS diode protects and where it goes The STMicroelectronics SMAJ28CA-TR is a bidirectional Zener-type transient voltage suppression diode from the TRANSIL™ SMAJ series, designed to clamp voltage spikes on 28 V nominal rails. The DO-214AC (SMA) surface-mount package suits automated assembly on standard PCB footprints. ## 28 V rail protection — the voltage window The reverse standoff voltage of 28 V means this diode will not conduct at the normal operating rail voltage, so it sits across a 24 V or 28 V supply without leakage issues. Breakdown starts at 31.1 V minimum, and clamping is guaranteed at 59 V maximum at the peak pulse current of 39 A (8/20 µs waveform). That 31 V to 59 V window gives the designer a clear margin: the protected circuit must survive a 59 V pulse, and the rail must never exceed 28 V steady-state. With a single bidirectional channel, the SMAJ28CA-TR clamps positive and negative transients symmetrically. That saves a diode pair on AC signal lines or on DC rails where reverse-polarity events are possible. No power line protection is built in — this is a pure transient clamp, not a crowbar or a filter.","metaTitle":"STMicroelectronics SMAJ28CA-TR TRANSIL TVS Diode, 400W","metaDescription":"STMicroelectronics SMAJ28CA-TR bidirectional TVS diode, 28V reverse standoff, 400W peak pulse power, DO-214AC SMA package, -55°C to 150°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Circuit Protection"],"specifications":{"Mfr":"STMicroelectronics","Type":"Zener","Series":"SMAJ, TRANSIL™","Package":"Tape & Reel (TR); Cut Tape (CT)","Applications":"General Purpose","Mounting Type":"Surface Mount","Package / Case":"DO-214AC, SMA","Product Status":"Active","lifecycle_stage":"eol_hot","Power - Peak Pulse":"400W","Base Product Number":"SMAJ28","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)":"31.1V","Voltage - Clamping (Max) @ Ipp":"59V","Voltage - Reverse Standoff (Typ)":"28V","Current - Peak Pulse (10/1000µs)":"39A (8/20µs)"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.4700","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/cb45a0c551131e855efff64db719fd1e.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/SMAJ28CA-TR/alternatives.json"},"ai":{"faq":[{"question":"Is SMAJ28CA-TR bidirectional?","answer":"Yes, the SMAJ28CA-TR is a single-channel bidirectional TVS diode. It clamps both positive and negative transients symmetrically, so it works on AC signal lines or on DC rails where reverse polarity is a concern."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/stmicroelectronics/SMAJ28CA-TR","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/stmicroelectronics/SMAJ28CA-TR 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}}