74HC257D

{
  "schema_version": 1,
  "type": "component",
  "slug": "74hc257d",
  "title": "74HC257D",
  "brief": "Nexperia Signal Switches / Encoders & Decoders / Multiplexers, SOIC-16. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "logic",
    "74hc257d"
  ],
  "component": {
    "mpn": "74HC257D",
    "manufacturer": "Nexperia",
    "package": "SOIC-16",
    "pin_count": 16,
    "category": "Logic",
    "subcategory": "Signal Switches / Encoders & Decoders / Multiplexers",
    "datasheet": "https://assets.nexperia.com/documents/data-sheet/74HC257D.pdf",
    "parts": {
      "symbol": "74hc257d.kicad_sym",
      "footprint": "74hc257d.kicad_mod",
      "model_3d": "74hc257d-etched.glb",
      "model_3d_plain": "74hc257d.glb",
      "model_3d_step": "74hc257d-etched.step",
      "model_3d_step_plain": "74hc257d.step",
      "lbr": "74hc257d.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "S",
        "type": "input",
        "description": "Common data select input. Selects between the nI0 inputs (S=LOW) and nI1 inputs (S=HIGH) routed to the nY outputs."
      },
      {
        "number": "2",
        "name": "1I0",
        "type": "input",
        "description": "Data input from source 0 for multiplexer channel 1. Routed to 1Y when S=LOW and OE=LOW."
      },
      {
        "number": "3",
        "name": "1I1",
        "type": "input",
        "description": "Data input from source 1 for multiplexer channel 1. Routed to 1Y when S=HIGH and OE=LOW."
      },
      {
        "number": "4",
        "name": "1Y",
        "type": "tri_state",
        "description": "3-state multiplexer output for channel 1. High-impedance when OE=HIGH."
      },
      {
        "number": "5",
        "name": "2I0",
        "type": "input",
        "description": "Data input from source 0 for multiplexer channel 2. Routed to 2Y when S=LOW and OE=LOW."
      },
      {
        "number": "6",
        "name": "2I1",
        "type": "input",
        "description": "Data input from source 1 for multiplexer channel 2. Routed to 2Y when S=HIGH and OE=LOW."
      },
      {
        "number": "7",
        "name": "2Y",
        "type": "tri_state",
        "description": "3-state multiplexer output for channel 2. High-impedance when OE=HIGH."
      },
      {
        "number": "8",
        "name": "GND",
        "type": "power_in",
        "description": "Ground (0 V) reference."
      },
      {
        "number": "9",
        "name": "3Y",
        "type": "tri_state",
        "description": "3-state multiplexer output for channel 3. High-impedance when OE=HIGH."
      },
      {
        "number": "10",
        "name": "3I1",
        "type": "input",
        "description": "Data input from source 1 for multiplexer channel 3. Routed to 3Y when S=HIGH and OE=LOW."
      },
      {
        "number": "11",
        "name": "3I0",
        "type": "input",
        "description": "Data input from source 0 for multiplexer channel 3. Routed to 3Y when S=LOW and OE=LOW."
      },
      {
        "number": "12",
        "name": "4Y",
        "type": "tri_state",
        "description": "3-state multiplexer output for channel 4. High-impedance when OE=HIGH."
      },
      {
        "number": "13",
        "name": "4I1",
        "type": "input",
        "description": "Data input from source 1 for multiplexer channel 4. Routed to 4Y when S=HIGH and OE=LOW."
      },
      {
        "number": "14",
        "name": "4I0",
        "type": "input",
        "description": "Data input from source 0 for multiplexer channel 4. Routed to 4Y when S=LOW and OE=LOW."
      },
      {
        "number": "15",
        "name": "OE",
        "type": "input",
        "description": "3-state output enable input, active LOW. When OE=HIGH, all nY outputs are in the high-impedance OFF-state."
      },
      {
        "number": "16",
        "name": "VCC",
        "type": "power_in",
        "description": "Supply voltage. 2.0 V to 6.0 V for 74HC257; 4.5 V to 5.5 V for 74HCT257."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://assets.nexperia.com/documents/data-sheet/74HC257D.pdf",
        "pages": 15,
        "sha256": "9a5ab16a50053e88",
        "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"
    },
    "logic": {
      "family_id": "74HC257",
      "logic_family": "74HC",
      "function_code": "257",
      "function_class": "Multiplexer",
      "function_name": "Quad 2-Input Multiplexer, 3-State",
      "manufacturer": null,
      "is_specialty": false
    },
    "models_3d": [
      {
        "file": "74hc257d.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": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "74hc257d-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": "b5d0aeb7c5a7d7dbbcca7706947660f5c1392d193eb28edb1910b703d03a3a81",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "Nexperia",
      "Package": "SOIC-16",
      "Category": "Logic",
      "Pins": "16"
    }
  },
  "variants": [
    {
      "mpn": "74HC257DD",
      "kind": "packaging"
    },
    {
      "mpn": "74HC257DPW",
      "kind": "packaging"
    }
  ],
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "74hc257d"
  ],
  "discovery_pitch": "74HC257D (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",
    "74hc257d.kicad_sym",
    "74hc257d.kicad_mod",
    "74hc257d.glb",
    "74hc257d.step",
    "74hc257d.lbr",
    "docs/hero.png",
    "docs/74hc257d-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html"
  ],
  "visibility": {
    "public": true
  },
  "updated_at": "2026-09-24T14:56:57.607Z"
}