BC857B-QR

{
  "slug": "bc857b-qr",
  "version": "0.1.1",
  "type": "component",
  "description": "Nexperia Bipolar (BJT), SOT-23. Datasheet-verified pinout, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "transistors-thyristors",
    "bc857b-qr",
    "factory-2.0.0",
    "extractor-text"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
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    "README.md",
    "bc857b-qr.kicad_sym",
    "bc857b-qr.kicad_mod",
    "bc857b-qr.glb",
    "bc857b-qr.step",
    "bc857b-qr.lbr",
    "docs/hero.png",
    "docs/bc857b-qr-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "bc857b-qr-etched.step",
    "bc857b-qr-hero.glb",
    "bc857b-qr-hero.overlay.json"
  ],
  "component": {
    "mpn": "BC857B-QR",
    "manufacturer": "Nexperia",
    "package": "SOT-23",
    "pin_count": 3,
    "category": "Transistors/Thyristors",
    "subcategory": "Bipolar (BJT)",
    "datasheet": "https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590261262237409280",
    "parts": {
      "symbol": "bc857b-qr.kicad_sym",
      "footprint": "bc857b-qr.kicad_mod",
      "model_3d": "bc857b-qr-hero.glb",
      "model_3d_plain": "bc857b-qr.glb",
      "model_3d_step": "bc857b-qr-etched.step",
      "model_3d_step_plain": "bc857b-qr.step",
      "lbr": "bc857b-qr.lbr"
    },
    "distributor_links": {
      "lcsc": "C5121591"
    },
    "pins": [
      {
        "number": "1",
        "name": "B",
        "type": "input",
        "description": "Base terminal for transistor control; DC current gain (hFE) ranges from 220 to 475 at VCE = −5 V and IC = −2 mA."
      },
      {
        "number": "2",
        "name": "E",
        "type": "passive",
        "description": "Emitter terminal; maximum base-emitter voltage (VEBO) is −5 V."
      },
      {
        "number": "3",
        "name": "C",
        "type": "passive",
        "description": "Collector terminal; maximum collector-emitter voltage (VCEO) is −45 V and maximum collector current (IC) is −100 mA."
      }
    ],
    "provenance": {
      "extractor": "extract_pins 0.2",
      "factory_chain": {
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        "primary_model": "claude-haiku-4-5-20251001",
        "primary_mode": "text",
        "consensus_model": "claude-sonnet-4-6",
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [],
        "pages_sent": 13,
        "cost_usd": 0.1196,
        "at": "2026-09-23T16:43:35"
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        "pages": 13,
        "sha256": "51197e747b27e7b9",
        "source_tier": "lcsc"
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      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 3,
        "described": 3,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
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      "footprint": "viewers/footprint.html"
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    "models_3d": [
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        "file": "bc857b-qr.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
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        "centre_offset_mm": 0.0,
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        "checked": "2026-11-13",
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  },
  "title": "BC857B-QR",
  "brief": "Nexperia Bipolar (BJT), SOT-23. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "metadata": {
    "specs": {
      "Manufacturer": "Nexperia",
      "Package": "SOT-23",
      "Category": "Transistors/Thyristors",
      "Pins": "3"
    },
    "characteristics": {
      "version": 1,
      "source": "datasheet",
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      "rows": [
        {
          "name": "collector-base voltage",
          "symbol": "VCBO",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": -50,
          "conditions": "open emitter",
          "source_page": 3,
          "source": "datasheet"
        },
        {
          "name": "collector-emitter voltage",
          "symbol": "VCEO",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": -45,
          "conditions": "open base",
          "source_page": 3,
          "source": "datasheet"
        },
        {
          "name": "emitter-base voltage",
          "symbol": "VEBO",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": -5,
          "conditions": "open collector",
          "source_page": 3,
          "source": "datasheet"
        },
        {
          "name": "collector current",
          "symbol": "IC",
          "kind": "absolute_maximum",
          "unit": "mA",
          "min": null,
          "typ": null,
          "max": -100,
          "conditions": "",
          "source_page": 3,
          "source": "datasheet"
        },
        {
          "name": "peak collector current",
          "symbol": "ICM",
          "kind": "absolute_maximum",
          "unit": "mA",
          "min": null,
          "typ": null,
          "max": -200,
          "conditions": "",
          "source_page": 3,
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        },
        {
          "name": "peak base current",
          "symbol": "IBM",
          "kind": "absolute_maximum",
          "unit": "mA",
          "min": null,
          "typ": null,
          "max": -200,
          "conditions": "",
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        },
        {
          "name": "total power dissipation",
          "symbol": "Ptot",
          "kind": "absolute_maximum",
          "unit": "mW",
          "min": null,
          "typ": null,
          "max": 250,
          "conditions": "Tamb ≤ 25 °C; device mounted on FR4 PCB [1]",
          "source_page": 3,
          "source": "datasheet"
        },
        {
          "name": "junction temperature",
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          "kind": "absolute_maximum",
          "unit": "°C",
          "min": null,
          "typ": null,
          "max": 150,
          "conditions": "",
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        {
          "name": "ambient temperature",
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          "unit": "°C",
          "min": -65,
          "typ": null,
          "max": 150,
          "conditions": "",
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        {
          "name": "storage temperature",
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          "min": -65,
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          "max": 150,
          "conditions": "",
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        {
          "name": "thermal resistance from junction to ambient",
          "symbol": "Rth(j-a)",
          "kind": "thermal",
          "unit": "K/W",
          "min": null,
          "typ": null,
          "max": 500,
          "conditions": "in free air; device mounted on FR4 PCB, single-sided, 35 µm copper [1]",
          "source_page": 4,
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        },
        {
          "name": "collector-base breakdown voltage",
          "symbol": "V(BR)CBO",
          "kind": "electrical",
          "unit": "V",
          "min": -50,
          "typ": null,
          "max": null,
          "conditions": "IC = -100 µA; IE = 0 A",
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          "source": "datasheet"
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        {
          "name": "collector-emitter breakdown voltage",
          "symbol": "V(BR)CEO",
          "kind": "electrical",
          "unit": "V",
          "min": -45,
          "typ": null,
          "max": null,
          "conditions": "IC = -2 mA; IB = 0 A",
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          "source": "datasheet"
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        {
          "name": "emitter-base breakdown voltage",
          "symbol": "V(BR)EBO",
          "kind": "electrical",
          "unit": "V",
          "min": -5,
          "typ": null,
          "max": null,
          "conditions": "IC = 0 A; IE = -100 µA",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "collector-base cut-off current",
          "symbol": "ICBO",
          "kind": "electrical",
          "unit": "nA",
          "min": null,
          "typ": -1,
          "max": -15,
          "conditions": "VCB = -30 V; IE = 0 A",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "collector-base cut-off current",
          "symbol": "ICBO",
          "kind": "electrical",
          "unit": "µA",
          "min": null,
          "typ": null,
          "max": -4,
          "conditions": "VCB = -30 V; IE = 0 A; Tj = 150 °C",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "emitter-base cut-off current",
          "symbol": "IEBO",
          "kind": "electrical",
          "unit": "nA",
          "min": null,
          "typ": null,
          "max": -100,
          "conditions": "VEB = -5 V; IC = 0 A",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "DC current gain",
          "symbol": "hFE",
          "kind": "electrical",
          "unit": "",
          "min": 220,
          "typ": null,
          "max": 475,
          "conditions": "VCE = -5 V; IC = -2 mA",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "collector-emitter saturation voltage",
          "symbol": "VCEsat",
          "kind": "electrical",
          "unit": "mV",
          "min": null,
          "typ": -75,
          "max": -300,
          "conditions": "IC = -10 mA; IB = -0.5 mA",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "collector-emitter saturation voltage",
          "symbol": "VCEsat",
          "kind": "electrical",
          "unit": "mV",
          "min": null,
          "typ": -250,
          "max": -650,
          "conditions": "IC = -100 mA; IB = -5 mA; pulsed; tp ≤ 300 μs; δ ≤ 0.02 [1]",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "base-emitter voltage",
          "symbol": "VBE",
          "kind": "electrical",
          "unit": "mV",
          "min": -600,
          "typ": -650,
          "max": -750,
          "conditions": "VCE = -5 V; IC = -2 mA",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "base-emitter voltage",
          "symbol": "VBE",
          "kind": "electrical",
          "unit": "mV",
          "min": null,
          "typ": null,
          "max": -820,
          "conditions": "VCE = -5 V; IC = -10 mA",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "transition frequency",
          "symbol": "fT",
          "kind": "electrical",
          "unit": "MHz",
          "min": 100,
          "typ": null,
          "max": null,
          "conditions": "VCE = -5 V; IC = -10 mA; f = 100 MHz",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "noise figure",
          "symbol": "NF",
          "kind": "electrical",
          "unit": "dB",
          "min": null,
          "typ": 2,
          "max": 10,
          "conditions": "IC = -200 µA; VCE = -5 V; RS = 2 kΩ; f = 1 kHz; B = 200 Hz",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "base-emitter saturation voltage",
          "symbol": "VBEsat",
          "kind": "electrical",
          "unit": "mV",
          "min": null,
          "typ": -700,
          "max": null,
          "conditions": "IC = -10 mA; IB = -0.5 mA; pulsed; tp ≤ 300 μs; δ ≤ 0.02 [1]",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "base-emitter saturation voltage",
          "symbol": "VBEsat",
          "kind": "electrical",
          "unit": "mV",
          "min": null,
          "typ": -850,
          "max": null,
          "conditions": "IC = -100 mA; IB = -5 mA; pulsed; tp ≤ 300 μs; δ ≤ 0.02 [1]",
          "source_page": 5,
          "source": "datasheet"
        },
        {
          "name": "collector capacitance",
          "symbol": "Cc",
          "kind": "electrical",
          "unit": "pF",
          "min": null,
          "typ": 4.5,
          "max": null,
          "conditions": "VCB = -10 V; IE = ie = 0 A; f = 1 MHz",
          "source_page": 5,
          "source": "datasheet"
        }
      ]
    }
  },
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  "discovery_pitch": "BC857B-QR (Nexperia) component page with datasheet-verified CAD.",
  "visibility": "public"
}