ULN2803A Darlington Array

{
  "schema_version": 1,
  "type": "component",
  "slug": "uln2803a",
  "title": "ULN2803A Darlington Array",
  "brief": "Eight NPN Darlington pairs with 50 V, 500 mA outputs and clamp diodes for inductive loads.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "darlington",
    "driver",
    "relay-driver",
    "transistor-array",
    "ti",
    "soic-18"
  ],
  "component": {
    "mpn": "ULN2803A",
    "manufacturer": "Texas Instruments",
    "package": "SOIC-18",
    "pin_count": 18,
    "category": "Driver",
    "subcategory": "Transistor Array / Driver",
    "datasheet": "https://www.ti.com/lit/ds/symlink/uln2803c.pdf",
    "parts": {
      "symbol": "uln2803a.kicad_sym",
      "footprint": "uln2803a.kicad_mod",
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      "model_3d_plain": "uln2803a.glb",
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      "model_3d_step": "uln2803a-etched.step",
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    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "1B",
        "type": "input",
        "description": "Channel 1 Darlington base input. Drives channel 1 output through 2.7kΩ series base resistor; compatible with TTL/CMOS logic up to VI(max)=30V."
      },
      {
        "number": "2",
        "name": "2B",
        "type": "input",
        "description": "Channel 2 Darlington base input. Drives channel 2 output through 2.7kΩ series base resistor."
      },
      {
        "number": "3",
        "name": "3B",
        "type": "input",
        "description": "Channel 3 Darlington base input. Drives channel 3 output through 2.7kΩ series base resistor."
      },
      {
        "number": "4",
        "name": "4B",
        "type": "input",
        "description": "Channel 4 Darlington base input. Drives channel 4 output through 2.7kΩ series base resistor."
      },
      {
        "number": "5",
        "name": "5B",
        "type": "input",
        "description": "Channel 5 Darlington base input. Drives channel 5 output through 2.7kΩ series base resistor."
      },
      {
        "number": "6",
        "name": "6B",
        "type": "input",
        "description": "Channel 6 Darlington base input. Drives channel 6 output through 2.7kΩ series base resistor."
      },
      {
        "number": "7",
        "name": "7B",
        "type": "input",
        "description": "Channel 7 Darlington base input. Drives channel 7 output through 2.7kΩ series base resistor."
      },
      {
        "number": "8",
        "name": "8B",
        "type": "input",
        "description": "Channel 8 Darlington base input. Drives channel 8 output through 2.7kΩ series base resistor."
      },
      {
        "number": "9",
        "name": "GND",
        "type": "power_in",
        "description": "Common emitter of all eight Darlington pairs. Typically tied to system ground; also serves as the return for the input logic reference."
      },
      {
        "number": "10",
        "name": "COM",
        "type": "power_in",
        "description": "Common cathode of the internal free-wheeling clamp diodes. Tie to the inductive-load supply (VSUP) so kickback energy is clamped when the Darlington turns off; may be left open when driving purely resistive loads."
      },
      {
        "number": "11",
        "name": "8C",
        "type": "output",
        "description": "Channel 8 Darlington open-collector output. Sinks up to 500mA per channel from loads returned to COM/VSUP (≤50V)."
      },
      {
        "number": "12",
        "name": "7C",
        "type": "output",
        "description": "Channel 7 Darlington open-collector output. Sinks up to 500mA per channel."
      },
      {
        "number": "13",
        "name": "6C",
        "type": "output",
        "description": "Channel 6 Darlington open-collector output. Sinks up to 500mA per channel."
      },
      {
        "number": "14",
        "name": "5C",
        "type": "output",
        "description": "Channel 5 Darlington open-collector output. Sinks up to 500mA per channel."
      },
      {
        "number": "15",
        "name": "4C",
        "type": "output",
        "description": "Channel 4 Darlington open-collector output. Sinks up to 500mA per channel."
      },
      {
        "number": "16",
        "name": "3C",
        "type": "output",
        "description": "Channel 3 Darlington open-collector output. Sinks up to 500mA per channel."
      },
      {
        "number": "17",
        "name": "2C",
        "type": "output",
        "description": "Channel 2 Darlington open-collector output. Sinks up to 500mA per channel."
      },
      {
        "number": "18",
        "name": "1C",
        "type": "output",
        "description": "Channel 1 Darlington open-collector output. Sinks up to 500mA per channel."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://www.ti.com/lit/ds/symlink/uln2803c.pdf",
        "pages": 21,
        "sha256": "12d7302794e2a590",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 18,
        "described": 18,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
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    "models_3d": [
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        "file": "uln2803a.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          10.3,
          11.55,
          2.75
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        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "05ad7d4945131c76ec7b9448dd9cbb5376b56adcd564c58d93e50ca7870fab1f",
        "checked": "2026-10-07",
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        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
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  },
  "metadata": {
    "specs": {
      "Type": "8-channel NPN Darlington array (sink)",
      "Output voltage": "50 V max",
      "Output current": "500 mA per channel (peak)",
      "Input": "Logic-level (2.7 V and 5 V compatible)",
      "Clamp diodes": "Integrated common-cathode (COM pin)",
      "Operating temperature": "-40 C to 85 C"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
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  "discovery_triggers": [
    "Darlington array",
    "relay driver",
    "drive 8 loads",
    "stepper unipolar driver",
    "solenoid driver"
  ],
  "discovery_pitch": "Drive eight relays, solenoids, or LED banks from logic pins, with built-in flyback clamp diodes.",
  "author": {
    "name": "Ray"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
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  "files": [
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  "variants": [
    {
      "mpn": "ULN2803ADW",
      "kind": "unknown"
    }
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}