BD137 NPN Power Transistor

{
  "schema_version": 1,
  "type": "component",
  "slug": "bd137",
  "title": "BD137 NPN Power Transistor",
  "brief": "NPN medium-power transistor, 60 V / 1.5 A, in TO-126 for audio and driver stages.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "transistor",
    "bjt",
    "npn",
    "medium-power",
    "to-126",
    "st"
  ],
  "component": {
    "mpn": "BD137",
    "manufacturer": "STMicroelectronics",
    "package": "TO-126",
    "pin_count": 3,
    "category": "Discrete Semiconductor",
    "subcategory": "Bipolar Transistor (BJT)",
    "datasheet": "https://www.st.com/resource/en/datasheet/bd135.pdf",
    "parts": {
      "symbol": "bd137.kicad_sym",
      "footprint": "bd137.kicad_mod",
      "model_3d": "bd137-etched.glb",
      "model_3d_plain": "bd137.glb",
      "model_3d_step": "bd137-etched.step",
      "model_3d_step_plain": "bd137.step",
      "lbr": "bd137.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "E",
        "type": "passive",
        "description": "Emitter. Typically the low-side reference of the transistor; VCE(sat) ≤ 0.5 V at IC = 0.5 A, IB = 50 mA."
      },
      {
        "number": "2",
        "name": "C",
        "type": "passive",
        "description": "Collector. Also thermally/electrically tied to the metal mounting tab of the SOT-32 (TO-126) package. Rated IC = 1.5 A continuous, ICM = 3 A peak; VCEO ≈ 60 V for BD137."
      },
      {
        "number": "3",
        "name": "B",
        "type": "input",
        "description": "Base. Controls collector current via base drive; VBE ≈ 1 V at IC = 0.5 A. Absolute max IB = 0.5 A, VEBO = 5 V."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://www.st.com/resource/en/datasheet/bd135.pdf",
        "pages": 9,
        "sha256": "9a72cdfa334700b8",
        "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": "bd137.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": "bd137-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": "04ebaa819e16cb4d497a1ddf2178cf069fdb74264769ed7bd767f9ca8fa3e5f8",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Type": "NPN medium-power transistor",
      "Collector-emitter voltage (VCEO)": "60 V",
      "Collector current (IC)": "1.5 A continuous (3 A peak)",
      "DC current gain (hFE)": "40 to 250",
      "Transition frequency (fT)": "190 MHz",
      "Power dissipation": "12.5 W",
      "Operating temperature": "-55 C to 150 C"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "medium-power NPN",
    "audio driver transistor",
    "60V NPN",
    "class-AB driver"
  ],
  "discovery_pitch": "A 60 V, 1.5 A NPN for audio driver and output stages, the mid-voltage member of the BD135/137/139 series.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "bd137.kicad_sym",
    "bd137.kicad_mod",
    "bd137.glb",
    "bd137.step",
    "bd137.lbr",
    "docs/hero.png",
    "docs/bd137-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "bd137-etched.step"
  ]
}