SM4T21AY

{
  "slug": "sm4t21ay",
  "version": "0.1.0",
  "type": "component",
  "description": "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.",
  "tags": [
    "component",
    "circuit protection",
    "sm4t21ay",
    "factory-2.0.0",
    "extractor-text"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "sm4t21ay.kicad_sym",
    "sm4t21ay.kicad_mod",
    "sm4t21ay.glb",
    "sm4t21ay.step",
    "sm4t21ay.lbr",
    "docs/hero.png",
    "docs/sm4t21ay-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "sm4t21ay-hero.glb",
    "sm4t21ay-hero.overlay.json",
    "sm4t21ay-etched.glb"
  ],
  "component": {
    "mpn": "SM4T21AY",
    "manufacturer": "STMicroelectronics",
    "package": "SMA(DO-214AC)",
    "pin_count": 2,
    "category": "Circuit Protection",
    "subcategory": "TVS",
    "datasheet": "https://www.st.com/resource/en/datasheet/sm4t21ay.pdf",
    "parts": {
      "symbol": "sm4t21ay.kicad_sym",
      "footprint": "sm4t21ay.kicad_mod",
      "model_3d": "sm4t21ay-hero.glb",
      "model_3d_plain": "sm4t21ay-etched.glb",
      "model_3d_step": "sm4t21ay-etched.step",
      "model_3d_step_plain": "sm4t21ay.step",
      "lbr": "sm4t21ay.lbr"
    },
    "distributor_links": {
      "lcsc": "C1974229",
      "digikey": "497-10910-2-ND",
      "mouser": "511-SM4T21AY"
    },
    "distributor_check": {
      "checked_at": "2026-10-30T17:06:39Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": "497-10910-2-ND",
        "status": "found",
        "lifecycle": "Active"
      },
      "mouser": {
        "pn": "511-SM4T21AY",
        "status": "found"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "K",
        "type": "passive",
        "description": "Cathode: the banded/marked end per the datasheet; pad 1 of the KiCad diode footprint."
      },
      {
        "number": "2",
        "name": "A",
        "type": "passive",
        "description": "Anode."
      }
    ],
    "provenance": {
      "extractor": "extract_pins",
      "factory_chain": {
        "factory": "2.0.0",
        "extractor": "extract_pins",
        "primary_model": "cathode-band convention",
        "primary_mode": "convention",
        "consensus_model": null,
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [
          "vision extraction: provenance cannot be text-verified; needs consensus"
        ],
        "pages_sent": 14,
        "cost_usd": 0.0019,
        "at": "2026-10-30T17:06:33"
      },
      "datasheet": {
        "url": "https://www.st.com/resource/en/datasheet/sm4t21ay.pdf",
        "pages": 14,
        "sha256": "84e42de0a72418e4",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 2,
        "described": 2,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "sm4t21ay.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          5.0,
          2.7,
          2.22
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "1cfddd4e3b1bf22b8fc6ee3258c2aade882ed7b85b528e23b9db42437775a1db",
        "checked": "2026-10-30",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "sm4t21ay-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          5.0,
          2.7,
          2.22
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "dcbb18b5a8cd75113bc54d1d5951353902cb0d8222fb7f6ea570f0f6a71a8bf1",
        "checked": "2026-10-30",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ],
    "package_dims": {
      "package_code": "SMA",
      "source_page": 7,
      "D": {
        "nom_mm": 2.575,
        "range_mm": [
          2.25,
          2.9
        ]
      },
      "E1": {
        "nom_mm": 4.275,
        "range_mm": [
          3.95,
          4.6
        ]
      },
      "E": {
        "nom_mm": 5.075,
        "range_mm": [
          4.8,
          5.35
        ]
      },
      "A": {
        "nom_mm": 2.175,
        "range_mm": [
          1.9,
          2.45
        ]
      },
      "source": "datasheet package drawing, every number found on its page (extract_pins --task dims)",
      "model_check": {
        "file": "sm4t21ay.step",
        "verdict": "PASS",
        "reasons": [
          "height and body within the datasheet's package drawing"
        ],
        "by": "factory/package_fit.py"
      }
    }
  }
}