BC857A

{
  "slug": "bc857a",
  "version": "0.1.0",
  "type": "component",
  "description": "Nexperia Bipolar (BJT), SOT-23. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "transistors-thyristors",
    "bc857a",
    "factory-2.0.0",
    "extractor-text"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "bc857a.kicad_sym",
    "bc857a.kicad_mod",
    "bc857a.glb",
    "bc857a.step",
    "bc857a.lbr",
    "docs/hero.png",
    "docs/bc857a-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "bc857a-hero.glb",
    "bc857a-hero.overlay.json"
  ],
  "component": {
    "mpn": "BC857A",
    "manufacturer": "Nexperia",
    "package": "SOT-23",
    "pin_count": 3,
    "category": "Transistors/Thyristors",
    "subcategory": "Bipolar (BJT)",
    "datasheet": "https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586188896933306368",
    "parts": {
      "symbol": "bc857a.kicad_sym",
      "footprint": "bc857a.kicad_mod",
      "model_3d": "bc857a-hero.glb",
      "model_3d_plain": "bc857a.glb",
      "model_3d_step": "bc857a-etched.step",
      "model_3d_step_plain": "bc857a.step",
      "lbr": "bc857a.lbr"
    },
    "distributor_links": {
      "lcsc": "C201757",
      "digikey": "4878-BC857ATR-ND",
      "mouser": "583-BC857A"
    },
    "distributor_check": {
      "checked_at": "2026-10-09T14:48:26Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": "4878-BC857ATR-ND",
        "status": "found",
        "lifecycle": "Active"
      },
      "mouser": {
        "pn": "583-BC857A",
        "status": "found"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "B",
        "type": "input",
        "description": "Base terminal of the PNP transistor; the datasheet limits the emitter-base voltage to -5 V (VEBO) and the peak base current to -200 mA (IBM)."
      },
      {
        "number": "2",
        "name": "E",
        "type": "passive",
        "description": "Emitter terminal of the PNP transistor; the emitter-base breakdown voltage is -5 V minimum at IE = -100 µA, and VEBO is limited to -5 V."
      },
      {
        "number": "3",
        "name": "C",
        "type": "passive",
        "description": "Collector terminal of the PNP transistor; for BC857A the collector-emitter voltage is limited to -45 V (VCEO) and the collector current to -100 mA (IC), with a peak of -200 mA (ICM)."
      }
    ],
    "provenance": {
      "extractor": "extract_pins 0.3",
      "factory_chain": {
        "factory": "2.0.0",
        "extractor": "extract_pins 0.3",
        "primary_model": "claude-haiku-5-5",
        "primary_mode": "text",
        "consensus_model": "claude-sonnet-5-5",
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [
          "extractor flagged: The datasheet's pinning table (Table 3) gives only the pin numbers, symbols B/E/C and the generic na"
        ],
        "pages_sent": 13,
        "cost_usd": 0.0545,
        "at": "2026-10-09T14:46:10"
      },
      "datasheet": {
        "url": "https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8586188896933306368",
        "pages": 13,
        "sha256": "d9a836e40dd8f1e7",
        "source_tier": "lcsc"
      },
      "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": "bc857a.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          2.5,
          3.0,
          1.2
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "dd5d1711204e1d8d26cd11490923bd84340820baa69538c385a4300ec2539bc0",
        "checked": "2026-10-09",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "bc857a-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          2.5,
          3.0,
          1.2
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "87378554b05ae72fd3b02a2fdcd2a91e39d9f98e10910f2cdd11cd80c41dd7ed",
        "checked": "2026-10-09",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  }
}