component

SM4T21AY

Public Made by Adom

by adom

STMicroelectronics TVS, SMA(DO-214AC). Unpolarised two-terminal part: the datasheet prints no pin numbers, so pins 1 and 2 follow the library convention, KiCad symbol/footprint/3D.

componentcircuit protectionsm4t21ayfactory-2.0.0extractor-text

Verified SM4T21AY

by Ray · last 30 Oct 2026 · 1 record · files match
SymbolFootprint3D modelPins

Verification log 1 record

30 Oct 2026RayPublished by the parts factory: tier mfr, 2 pinsfiles match
SymbolFootprint3D modelPinsfor all variants
  • ✓component-page-verify: PASS
  • ✓cad_props: Datasheet, MPN and distributor properties match page.json
  • ✓component: SM4T21AY · SMA(DO-214AC) · 2 pins
  • ✓copper: 2 copper pads, none touching another net
  • ✓datasheet: all 2 pin names found in the 14-page datasheet
  • ✓distributor: lcsc C1974229, digikey 497-10910-2-ND, mouser 511-SM4T21AY
  • ✓family: D_SMA
  • ✓files: 7 declared files present
  • ✓hero: docs/hero.png 4000x2500
  • ✓lbr: OK: /tmp/cpv-fekrr8j9/x.lbr is a valid EAGLE .lbr with complete deviceset
  • ✓license: CC-BY-SA-4.0
  • ✓models_3d: 2 records
  • ✓package_fit: height and body within the datasheet's package drawing (datasheet p.7)
  • ✓pads: 2 pins = 2 pads
  • ✓pose: 2 STEP(s) Z-up, seated, centred
  • ✓symbol: 2 pins agree
  • ✓visibility: public, source open
Evidencedatasheet
Verified files✓ sm4t21ay.kicad_sym✓ sm4t21ay.kicad_mod✓ sm4t21ay.step
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Made with KiCad 10.0 · needs KiCad 10.0 or later to open · KiCad file format 20260206
Name Last commit message Last updated
docs Publish 0.1.0 · Ray 4h ago
viewers sm4t21ay: viewers · Ray 4h ago
package.json Publish 0.1.0 · Ray 4h ago
page.json Set visibility: public · Ray 4h ago
README.md Publish 0.1.0 · Ray 4h ago
sm4t21ay-etched.glb Publish 0.1.0 · Ray 4h ago
sm4t21ay-etched.step sm4t21ay: factory component page (tier=mfr) · Ray 4h ago
sm4t21ay-hero.glb sm4t21ay: hero GLB from the etched model (keeps the MPN mark) · Ray 4h ago
sm4t21ay-hero.overlay.json Publish 0.1.0 · Ray 4h ago
sm4t21ay.glb Publish 0.1.0 · Ray 4h ago
sm4t21ay.kicad_mod Publish 0.1.0 · Ray 4h ago
sm4t21ay.kicad_sym Publish 0.1.0 · Ray 4h ago
sm4t21ay.lbr Publish 0.1.0 · Ray 4h ago
sm4t21ay.step Publish 0.1.0 · Ray 4h ago
verification.json Verified: Published by the parts factory: tier mfr, 2 pins · Ray 4h ago

SM4T21AY

STMicroelectronics · TVS · SMA(DO-214AC)

SM4T21AY 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 K passive Cathode: the banded/marked end per the datasheet; pad 1 of the KiCad diode footprint.
2 A passive Anode.

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
Reverse leakage current at VRM, 25 °C IRM 0.2 µA at VRM, 25 °C 3
Reverse leakage current at VRM, 85 °C IRM 1 µA at VRM, 85 °C 3
Breakdown voltage VBR 20 21.1 22.2 V at IBR = 1 mA 3
Clamping voltage, 10/1000 µs VCL 29.2 V 10/1000 µs waveform 3
Peak pulse current, 10/1000 µs IPP 13.7 A 10/1000 µs waveform 3
Dynamic resistance, 10/1000 µs RD 0.514 Ω 10/1000 µs waveform 3
Clamping voltage, 8/20 µs VCL 39.3 V 8/20 µs waveform 3
Peak pulse current, 8/20 µs IPP 59 A 8/20 µs waveform 3
Dynamic resistance, 8/20 µs RD 0.291 Ω 8/20 µs waveform 3
Peak pulse voltage, IEC 61000-4-2 contact discharge VPP 30 kV IEC 61000-4-2, C = 150 pF, R = 330 Ω, contact discharge 2
Peak pulse voltage, IEC 61000-4-2 air discharge VPP 30 kV IEC 61000-4-2, C = 150 pF, R = 330 Ω, air discharge 2
Peak pulse voltage, ISO10605 contact discharge VPP 30 kV ISO10605, C = 330 pF, R = 330 Ω, contact discharge 2
Peak pulse voltage, ISO10605 air discharge VPP 30 kV ISO10605, C = 330 pF, R = 330 Ω, air discharge 2
Peak pulse power dissipation PPP 400 W Tj initial = Tamb 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 copper area under each lead 5

CAD (KiCad official)

  • Symbol: SM4T21AY
  • Footprint: Diode_SMD:D_SMA
  • 3D model: SMA(DO-214AC) (KiCad packages3D, STEP)
  • 3D model files: sm4t21ay-etched.step / sm4t21ay-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); sm4t21ay.step / sm4t21ay.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: STMicroelectronics datasheet (14 pp, sha256 84e42de0a72418e4, retrieved 2026-10-30, tier: manufacturer)
  • Extractor: parts-factory 2.0.0 / extract_pins, primary cathode-band convention (convention), consensus off (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).

Datasheet PDF