SN74AHCT138DR

{
  "slug": "sn74ahct138dr",
  "version": "0.1.0",
  "type": "component",
  "description": "Texas Instruments Signal Switches, Multiplexers, Decoders, SOIC-16. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "logic",
    "sn74ahct138dr",
    "factory-2.0.0",
    "extractor-text"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "sn74ahct138dr.kicad_sym",
    "sn74ahct138dr.kicad_mod",
    "sn74ahct138dr.glb",
    "sn74ahct138dr.step",
    "sn74ahct138dr.lbr",
    "docs/hero.png",
    "docs/sn74ahct138dr-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "sn74ahct138dr-hero.glb",
    "sn74ahct138dr-hero.overlay.json"
  ],
  "component": {
    "mpn": "SN74AHCT138DR",
    "manufacturer": "Texas Instruments",
    "package": "SOIC-16",
    "pin_count": 16,
    "category": "Logic",
    "subcategory": "Signal Switches, Multiplexers, Decoders",
    "datasheet": "https://www.ti.com/lit/ds/symlink/sn74ahct138.pdf",
    "parts": {
      "symbol": "sn74ahct138dr.kicad_sym",
      "footprint": "sn74ahct138dr.kicad_mod",
      "model_3d": "sn74ahct138dr-hero.glb",
      "model_3d_plain": "sn74ahct138dr.glb",
      "model_3d_step": "sn74ahct138dr-etched.step",
      "model_3d_step_plain": "sn74ahct138dr.step",
      "lbr": "sn74ahct138dr.lbr"
    },
    "distributor_links": {
      "lcsc": "C354153",
      "digikey": "296-14701-2-ND",
      "mouser": "595-SN74AHCT138DR"
    },
    "distributor_check": {
      "checked_at": "2026-10-08T03:19:56Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": "296-14701-2-ND",
        "status": "found",
        "lifecycle": "Active"
      },
      "mouser": {
        "pn": "595-SN74AHCT138DR",
        "status": "found"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "A",
        "type": "input",
        "description": "Address input A of the 3-line to 8-line decoder; inputs are TTL-voltage compatible and must not be left floating."
      },
      {
        "number": "2",
        "name": "B",
        "type": "input",
        "description": "Address input B of the 3-line to 8-line decoder; inputs are TTL-voltage compatible and must not be left floating."
      },
      {
        "number": "3",
        "name": "C",
        "type": "input",
        "description": "Address input C of the 3-line to 8-line decoder; inputs are TTL-voltage compatible and must not be left floating."
      },
      {
        "number": "4",
        "name": "G2A",
        "type": "input",
        "description": "Strobe (enable) input 2A, active low, used with G2B and G1 to enable the decoder outputs."
      },
      {
        "number": "5",
        "name": "G2B",
        "type": "input",
        "description": "Strobe (enable) input 2B, active low, used with G2A and G1 to enable the decoder outputs."
      },
      {
        "number": "6",
        "name": "G1",
        "type": "input",
        "description": "Strobe (enable) input G1, used with G2A and G2B to enable the decoder outputs."
      },
      {
        "number": "7",
        "name": "Y7",
        "type": "output",
        "description": "Decoder output 7, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "8",
        "name": "GND",
        "type": "power_in",
        "description": "Ground reference for the device."
      },
      {
        "number": "9",
        "name": "Y6",
        "type": "output",
        "description": "Decoder output 6, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "10",
        "name": "Y5",
        "type": "output",
        "description": "Decoder output 5, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "11",
        "name": "Y4",
        "type": "output",
        "description": "Decoder output 4, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "12",
        "name": "Y3",
        "type": "output",
        "description": "Decoder output 3, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "13",
        "name": "Y2",
        "type": "output",
        "description": "Decoder output 2, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "14",
        "name": "Y1",
        "type": "output",
        "description": "Decoder output 1, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "15",
        "name": "Y0",
        "type": "output",
        "description": "Decoder output 0, driven by the 3-line to 8-line decode of inputs A, B and C when enabled."
      },
      {
        "number": "16",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply; recommended supply range is 1.5 V to 5.5 V and each VCC terminal should have a bypass capacitor (0.1 µF recommended)."
      }
    ],
    "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 pin table (Table 3-1) gives pin numbers for the shared D/DB/DGV/N/NS/PW pinout with no package-s; Output descriptions are generalized from the pin function table, which says only 'Output N'; the dat; VCC type is power_in per KiCad ERC convention for supply pins; the datasheet labels it 'P' (Power). "
        ],
        "pages_sent": 11,
        "cost_usd": 0.0602,
        "at": "2026-10-08T03:19:38"
      },
      "datasheet": {
        "url": "https://www.ti.com/lit/ds/symlink/sn74ahct138.pdf",
        "pages": 40,
        "sha256": "e1c16c1f6e6b2f98",
        "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"
    },
    "models_3d": [
      {
        "file": "sn74ahct138dr.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.0,
          9.9,
          1.75
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "d5eeddb4c0b304dc61950919b126fc61d7586abd5f16ab71a2a79759ec6498bf",
        "checked": "2026-10-08",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "sn74ahct138dr-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.0,
          9.9,
          1.75
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "d6b7a151687ffb73641389afe0fb55b54ae94fa3988831f9b914f67394715f8d",
        "checked": "2026-10-08",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  }
}