BD438

{
  "schema_version": 1,
  "type": "component",
  "slug": "bd438",
  "title": "BD438",
  "brief": "STMicroelectronics Bipolar (BJT), TO-126-3. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "transistors-thyristors",
    "bd438",
    "factory-2.0.0",
    "extractor-text"
  ],
  "component": {
    "mpn": "BD438",
    "manufacturer": "STMicroelectronics",
    "package": "TO-126-3",
    "pin_count": 3,
    "category": "Transistors/Thyristors",
    "subcategory": "Bipolar (BJT)",
    "datasheet": "https://www.st.com/resource/en/datasheet/bd438.pdf",
    "parts": {
      "symbol": "bd438.kicad_sym",
      "footprint": "bd438.kicad_mod",
      "model_3d": "bd438-etched.glb",
      "model_3d_plain": "bd438.glb",
      "model_3d_step": "bd438-etched.step",
      "model_3d_step_plain": "bd438.step",
      "lbr": "bd438.lbr"
    },
    "distributor_links": {
      "lcsc": "C2832765"
    },
    "pins": [
      {
        "number": "1",
        "name": "Base",
        "type": "input",
        "description": "Control input terminal with maximum base current of 1 A"
      },
      {
        "number": "2",
        "name": "Collector",
        "type": "output",
        "description": "Collector terminal with maximum collector current of 4 A and collector-emitter voltage of 45 V"
      },
      {
        "number": "3",
        "name": "Emitter",
        "type": "output",
        "description": "Emitter terminal with maximum emitter-base voltage of 5 V"
      }
    ],
    "provenance": {
      "extractor": "extract_pins 0.2",
      "factory_chain": {
        "factory": "2.0.0",
        "extractor": "extract_pins 0.2",
        "primary_model": "claude-haiku-4-5-20251001",
        "primary_mode": "text",
        "consensus_model": "claude-sonnet-5",
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [],
        "pages_sent": 4,
        "cost_usd": 0.0731,
        "at": "2026-09-24T08:44:56"
      },
      "datasheet": {
        "url": "https://www.st.com/resource/en/datasheet/bd438.pdf",
        "pages": 4,
        "sha256": "eff0c287adc6d211",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 3,
        "described": 3,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "bd438.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "body on z = 0, through-hole leads below",
        "extents_mm": [
          8.0,
          3.25,
          23.75
        ],
        "zmin_mm": -9.75,
        "centre_offset_mm": 0.375,
        "footprint_binding": "identity",
        "sha256": "6cb4ab2049af821a4bd7162ee7b11b91bdea76f43915d9c1fbb0cb1cdeeaa9c6",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "bd438-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "body on z = 0, through-hole leads below",
        "extents_mm": [
          8.0,
          3.25,
          23.75
        ],
        "zmin_mm": -9.75,
        "centre_offset_mm": 0.375,
        "footprint_binding": "identity",
        "sha256": "992cf8677053efa6b9e4a7098113a3b246ad9562ba5c77d5671d04f9895c8528",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "STMicroelectronics",
      "Package": "TO-126-3",
      "Category": "Transistors/Thyristors",
      "Pins": "3"
    },
    "characteristics": {
      "version": 1,
      "source": "datasheet",
      "datasheet_sha256": "eff0c287adc6d211",
      "rows": [
        {
          "name": "Collector-Base Voltage",
          "symbol": "VCBO",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 45,
          "conditions": "IE = 0; PNP BD438 column (datasheet note: PNP voltage/current values are negative)",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Collector-Emitter Voltage",
          "symbol": "VCES",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 45,
          "conditions": "VBE = 0; PNP BD438 column (datasheet note: PNP voltage/current values are negative)",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Emitter-Base Voltage",
          "symbol": "VEBO",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 5,
          "conditions": "IC = 0",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Collector Current",
          "symbol": "IC",
          "kind": "absolute_maximum",
          "unit": "A",
          "min": null,
          "typ": null,
          "max": 4,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Collector Peak Current",
          "symbol": "ICM",
          "kind": "absolute_maximum",
          "unit": "A",
          "min": null,
          "typ": null,
          "max": 7,
          "conditions": "t ≤ 10 ms",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Base Current",
          "symbol": "IB",
          "kind": "absolute_maximum",
          "unit": "A",
          "min": null,
          "typ": null,
          "max": 1,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Total Dissipation",
          "symbol": "Ptot",
          "kind": "absolute_maximum",
          "unit": "W",
          "min": null,
          "typ": null,
          "max": 36,
          "conditions": "Tc ≤ 25 °C",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Storage Temperature",
          "symbol": "Tstg",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": -65,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Max. Operating Junction Temperature",
          "symbol": "Tj",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": null,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 1,
          "source": "datasheet"
        },
        {
          "name": "Thermal Resistance Junction-case Max",
          "symbol": "Rthj-case",
          "kind": "thermal",
          "unit": "°C/W",
          "min": null,
          "typ": null,
          "max": 3.5,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Thermal Resistance Junction-ambient Max",
          "symbol": "Rthj-amb",
          "kind": "thermal",
          "unit": "°C/W",
          "min": null,
          "typ": null,
          "max": 100,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Collector Cut-off Current (IE = 0)",
          "symbol": "ICBO",
          "kind": "electrical",
          "unit": "µA",
          "min": null,
          "typ": null,
          "max": 100,
          "conditions": "for BD437/438 VCB = 45 V",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Collector Cut-off Current (VBE = 0)",
          "symbol": "ICES",
          "kind": "electrical",
          "unit": "µA",
          "min": null,
          "typ": null,
          "max": 100,
          "conditions": "for BD437/438 VCE = 45 V",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Emitter Cut-off Current (IC = 0)",
          "symbol": "IEBO",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": null,
          "max": 1,
          "conditions": "VEB = 5 V",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Collector-Emitter Sustaining Voltage (IB = 0)",
          "symbol": "VCEO(sus)",
          "kind": "electrical",
          "unit": "V",
          "min": 45,
          "typ": null,
          "max": null,
          "conditions": "IC = 100 mA for BD437/438; pulsed: pulse duration 300 µs, duty cycle 1.5 %",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Collector-Emitter Saturation Voltage",
          "symbol": "VCE(sat)",
          "kind": "electrical",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 0.6,
          "conditions": "IC = 2 A, IB = 0.2 A for BD437/438; pulsed: pulse duration 300 µs, duty cycle 1.5 %",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Base-Emitter Voltage",
          "symbol": "VBE",
          "kind": "electrical",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 0.58,
          "conditions": "IC = 10 mA, VCE = 5 V; pulsed: pulse duration 300 µs, duty cycle 1.5 %",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Base-Emitter Voltage",
          "symbol": "VBE",
          "kind": "electrical",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 1.2,
          "conditions": "IC = 2 A, VCE = 1 V for BD437/438; pulsed: pulse duration 300 µs, duty cycle 1.5 %",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "DC Current Gain",
          "symbol": "hFE",
          "kind": "electrical",
          "unit": "",
          "min": 30,
          "typ": null,
          "max": null,
          "conditions": "IC = 10 mA, VCE = 5 V for BD437/438; pulsed: pulse duration 300 µs, duty cycle 1.5 %",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Matched Pair DC Current Gain Ratio",
          "symbol": "hFE1/hFE2",
          "kind": "electrical",
          "unit": "",
          "min": null,
          "typ": null,
          "max": 1.4,
          "conditions": "IC = 500 mA, VCE = 1 V; pulsed: pulse duration 300 µs, duty cycle 1.5 %",
          "source_page": 2,
          "source": "datasheet"
        }
      ]
    }
  },
  "variants": [],
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "bd438"
  ],
  "discovery_pitch": "BD438 (STMicroelectronics) component page: datasheet pinout, KiCad symbol, footprint and 3D.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "bd438.kicad_sym",
    "bd438.kicad_mod",
    "bd438.glb",
    "bd438.step",
    "bd438.lbr",
    "docs/hero.png",
    "docs/bd438-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html"
  ],
  "visibility": {
    "public": true
  }
}