component
SM4T28CAY
Public Made by Adomby adom
STMicroelectronics TVS, SMA(DO-214AC). Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
Open in new tab ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.
Symbol & Footprint
Schematic Symbol
Open full view ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
PCB Footprint
Open full view ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
Datasheet
Open in new tab ↗Loads when you scroll to it. Unloads after 5 minutes in the background.
Contents
README
markdownSM4T28CAY
STMicroelectronics · TVS · SMA(DO-214AC)
SM4T28CAY from STMicroelectronics, in a SMA(DO-214AC). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | 1 | passive | Bidirectional (CA) Transil terminal with no cathode band, interchangeable with the other terminal; protects against ISO 7637-2 surges and ISO 10605 ESD (30 kV air and contact), with a 400 W (10/1000 µs) peak pulse rating. |
| 2 | 2 | passive | Bidirectional (CA) Transil terminal with no cathode band, interchangeable with the other terminal; SM4T28CAY has VRM 24 V, VBR 26.7 to 29.5 V at 1 mA, and VCL 38.9 V at 10.3 A (10/1000 µs). |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | STMicroelectronics |
| Package | SMA(DO-214AC) |
| Category | Circuit Protection |
| Pins | 2 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Leakage current at VRM, 25 °C | IRM | 0.2 | µA | @ VRM, 25 °C | 3 | ||
| Leakage current at VRM, 85 °C | IRM | 1 | µA | @ VRM, 85 °C | 3 | ||
| Stand-off voltage | VRM | 24 | V | 3 | |||
| Breakdown voltage | VBR | 26.7 | 28.1 | 29.5 | V | @ IR = 1 mA, pulse test tp < 50 ms, 25 °C | 3 |
| Clamping voltage 10/1000 µs | VCL | 38.9 | V | @ IPP = 10.3 A, 10/1000 µs | 3 | ||
| Dynamic resistance 10/1000 µs | RD | 0.912 | Ω | 10/1000 µs | 3 | ||
| Clamping voltage 8/20 µs | VCL | 50 | V | @ IPP = 46 A, 8/20 µs | 3 | ||
| Dynamic resistance 8/20 µs | RD | 0.446 | Ω | 8/20 µs | 3 | ||
| Voltage temperature coefficient | αT | 9.6 | 10-4/°C | 3 | |||
| Peak pulse voltage ISO 10605 contact discharge | VPP | 30 | kV | C = 150 pF, R = 330 Ω and C = 330 pF, R = 330 Ω | 2 | ||
| Peak pulse voltage ISO 10605 air discharge | VPP | 30 | kV | C = 150 pF, R = 330 Ω and C = 330 pF, R = 330 Ω | 2 | ||
| Peak pulse power dissipation | PPP | 400 | W | Tj initial = Tamb, Tamb = 25 °C | 2 | ||
| Storage temperature range | Tstg | -65 | 150 | °C | 2 | ||
| Operating junction temperature range | Tj | -55 | 150 | °C | 2 | ||
| Maximum lead temperature for soldering | TL | 260 | °C | during 10 s | 2 |
Materials and finish
As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | copper | ambient versus copper surface under each lead | 5 |
CAD (KiCad official)
- Symbol:
SM4T28CAY - Footprint:
Diode_SMD:D_SMA - 3D model: SMA(DO-214AC) (KiCad packages3D, STEP)
- 3D model files:
sm4t28cay-etched.step/sm4t28cay-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);sm4t28cay.step/sm4t28cay.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: STMicroelectronics datasheet (12 pp, sha256
b8d3299b0200f7ea, retrieved 2026-10-22, tier: manufacturer) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-sonnet-5-5(text), consensusclaude-sonnet-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).