74HC138D

{
  "schema_version": 1,
  "type": "component",
  "slug": "74hc138d",
  "title": "74HC138D",
  "brief": "Nexperia Signal Switches / Encoders & Decoders / Multiplexers, SOIC-16. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.2.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "logic",
    "74hc138d"
  ],
  "component": {
    "mpn": "74HC138D",
    "manufacturer": "Nexperia",
    "package": "SOIC-16",
    "pin_count": 16,
    "category": "Logic",
    "subcategory": "Signal Switches / Encoders & Decoders / Multiplexers",
    "datasheet": "https://assets.nexperia.com/documents/data-sheet/74HC138D.pdf",
    "parts": {
      "symbol": "74hc138d.kicad_sym",
      "footprint": "74hc138d.kicad_mod",
      "model_3d": "74hc138d-etched.glb",
      "model_3d_plain": "74hc138d.glb",
      "model_3d_step": "74hc138d-etched.step",
      "model_3d_step_plain": "74hc138d.step",
      "lbr": "74hc138d.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "A0",
        "type": "input",
        "description": "Address input 0 (LSB). Binary select input for the decoder; combined with A1 and A2 selects which of the eight outputs is asserted LOW when the device is enabled."
      },
      {
        "number": "2",
        "name": "A1",
        "type": "input",
        "description": "Address input 1. Binary select input for the decoder."
      },
      {
        "number": "3",
        "name": "A2",
        "type": "input",
        "description": "Address input 2 (MSB). Binary select input for the decoder."
      },
      {
        "number": "4",
        "name": "E1",
        "type": "input",
        "description": "Enable input 1, active LOW. Must be LOW (together with E2 LOW and E3 HIGH) to enable the selected output; otherwise all outputs are HIGH."
      },
      {
        "number": "5",
        "name": "E2",
        "type": "input",
        "description": "Enable input 2, active LOW. Must be LOW (together with E1 LOW and E3 HIGH) to enable outputs."
      },
      {
        "number": "6",
        "name": "E3",
        "type": "input",
        "description": "Enable input 3, active HIGH. Must be HIGH (together with E1 and E2 LOW) to enable outputs."
      },
      {
        "number": "7",
        "name": "Y7",
        "type": "output",
        "description": "Decoder output 7, active LOW. Asserted LOW when A2=A1=A0=1 and the device is enabled."
      },
      {
        "number": "8",
        "name": "GND",
        "type": "power_in",
        "description": "Ground reference (0 V). Common return for supply and logic signals."
      },
      {
        "number": "9",
        "name": "Y6",
        "type": "output",
        "description": "Decoder output 6, active LOW. Asserted LOW when A2A1A0 = 110 and device is enabled."
      },
      {
        "number": "10",
        "name": "Y5",
        "type": "output",
        "description": "Decoder output 5, active LOW. Asserted LOW when A2A1A0 = 101 and device is enabled."
      },
      {
        "number": "11",
        "name": "Y4",
        "type": "output",
        "description": "Decoder output 4, active LOW. Asserted LOW when A2A1A0 = 100 and device is enabled."
      },
      {
        "number": "12",
        "name": "Y3",
        "type": "output",
        "description": "Decoder output 3, active LOW. Asserted LOW when A2A1A0 = 011 and device is enabled."
      },
      {
        "number": "13",
        "name": "Y2",
        "type": "output",
        "description": "Decoder output 2, active LOW. Asserted LOW when A2A1A0 = 010 and device is enabled."
      },
      {
        "number": "14",
        "name": "Y1",
        "type": "output",
        "description": "Decoder output 1, active LOW. Asserted LOW when A2A1A0 = 001 and device is enabled."
      },
      {
        "number": "15",
        "name": "Y0",
        "type": "output",
        "description": "Decoder output 0, active LOW. Asserted LOW when A2A1A0 = 000 and device is enabled."
      },
      {
        "number": "16",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply voltage, 2.0 V to 6.0 V (recommended). Provides power to the internal logic."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://assets.nexperia.com/documents/data-sheet/74HC138D.pdf",
        "pages": 15,
        "sha256": "645120bc441507e9",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 16,
        "described": 16,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "pin1": {
      "pad": "1",
      "at": [
        -2.475,
        -4.445
      ],
      "corner": "top-left",
      "source": "silk-marker",
      "derived_from": "SOIC-16_3.9x9.9mm_P1.27mm@sha256:f9b5075740f7816c",
      "mark": "drawn"
    },
    "logic": {
      "family_id": "74HC138",
      "logic_family": "74HC",
      "function_code": "138",
      "function_class": "Decoder",
      "function_name": "3-to-8 Line Decoder/Demultiplexer",
      "manufacturer": null,
      "is_specialty": false
    },
    "models_3d": [
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        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
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          1.75
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "d5eeddb4c0b304dc61950919b126fc61d7586abd5f16ab71a2a79759ec6498bf",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "74hc138d-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
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        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "7a232031c04e8ab921ef3261f3fead8b03f26981c504db6bc3a5903fa674638a",
        "checked": "2026-10-19",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "Nexperia",
      "Package": "SOIC-16",
      "Category": "Logic",
      "Pins": "16"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "74hc138d"
  ],
  "discovery_pitch": "74HC138D (Nexperia) component page with datasheet-verified CAD.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "74hc138d.kicad_sym",
    "74hc138d.kicad_mod",
    "74hc138d.glb",
    "74hc138d.step",
    "74hc138d-etched.step",
    "74hc138d.lbr",
    "docs/hero.png",
    "docs/74hc138d-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html"
  ],
  "visibility": {
    "public": true
  },
  "updated_at": "2026-09-24T14:51:30.625Z"
}