SN74HCT138DR

{
  "schema_version": 1,
  "type": "component",
  "slug": "sn74hct138dr",
  "title": "SN74HCT138DR",
  "brief": "Texas Instruments Signal Switches, Multiplexers, Decoders, SOIC-16. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "logic",
    "sn74hct138dr",
    "factory-2.0.0",
    "extractor-text"
  ],
  "component": {
    "mpn": "SN74HCT138DR",
    "manufacturer": "Texas Instruments",
    "package": "SOIC-16",
    "pin_count": 16,
    "category": "Logic",
    "subcategory": "Signal Switches, Multiplexers, Decoders",
    "datasheet": "https://www.ti.com/lit/ds/symlink/sn74hct138.pdf",
    "parts": {
      "symbol": "sn74hct138dr.kicad_sym",
      "footprint": "sn74hct138dr.kicad_mod",
      "model_3d": "sn74hct138dr-etched.glb",
      "model_3d_plain": "sn74hct138dr.glb",
      "model_3d_step": "sn74hct138dr-etched.step",
      "model_3d_step_plain": "sn74hct138dr.step",
      "lbr": "sn74hct138dr.lbr"
    },
    "distributor_links": {
      "lcsc": "C352958"
    },
    "pins": [
      {
        "number": "1",
        "name": "A",
        "type": "input",
        "description": "Binary address select input A (LSB); TTL-compatible with VIH ≥ 2 V and VIL ≤ 0.8 V at VCC = 4.5 V to 5.5 V; selects one of eight outputs in combination with B and C."
      },
      {
        "number": "2",
        "name": "B",
        "type": "input",
        "description": "Binary address select input B (middle bit); TTL-compatible with VIH ≥ 2 V and VIL ≤ 0.8 V at VCC = 4.5 V to 5.5 V."
      },
      {
        "number": "3",
        "name": "C",
        "type": "input",
        "description": "Binary address select input C (MSB); TTL-compatible with VIH ≥ 2 V and VIL ≤ 0.8 V at VCC = 4.5 V to 5.5 V."
      },
      {
        "number": "4",
        "name": "~{G2A}",
        "type": "input",
        "description": "Active-low enable input G2A; all outputs forced high when this pin is high; must be low together with ~G2B and G1 high to enable the decoder; VIH ≥ 2 V, VIL ≤ 0.8 V, IImax = 1 µA."
      },
      {
        "number": "5",
        "name": "~{G2B}",
        "type": "input",
        "description": "Active-low enable input G2B; all outputs forced high when this pin is high; must be low together with ~G2A and G1 high to enable the decoder; VIH ≥ 2 V, VIL ≤ 0.8 V, IImax = 1 µA."
      },
      {
        "number": "6",
        "name": "G1",
        "type": "input",
        "description": "Active-high enable input; all outputs forced high when G1 is low; must be high together with ~G2A and ~G2B both low to enable the decoder; VIH ≥ 2 V, VIL ≤ 0.8 V, IImax = 1 µA."
      },
      {
        "number": "7",
        "name": "Y7",
        "type": "output",
        "description": "Active-low decoded output 7; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=111; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "8",
        "name": "GND",
        "type": "power_in",
        "description": "Ground reference (0 V); continuous current through GND pin must not exceed ±50 mA."
      },
      {
        "number": "9",
        "name": "Y6",
        "type": "output",
        "description": "Active-low decoded output 6; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=110; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "10",
        "name": "Y5",
        "type": "output",
        "description": "Active-low decoded output 5; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=101; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "11",
        "name": "Y4",
        "type": "output",
        "description": "Active-low decoded output 4; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=100; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "12",
        "name": "Y3",
        "type": "output",
        "description": "Active-low decoded output 3; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=011; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "13",
        "name": "Y2",
        "type": "output",
        "description": "Active-low decoded output 2; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=010; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "14",
        "name": "Y1",
        "type": "output",
        "description": "Active-low decoded output 1; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=001; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "15",
        "name": "Y0",
        "type": "output",
        "description": "Active-low decoded output 0; asserted low when G1=H, ~G2A=L, ~G2B=L and CBA=000; VOH ≥ 3.84 V at IOH = -4 mA, VOL ≤ 0.33 V at IOL = 4 mA, tpd ≤ 45 ns at VCC = 4.5 V."
      },
      {
        "number": "16",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply voltage; recommended operating range 4.5 V to 5.5 V; absolute maximum 7 V; each VCC pin should be bypassed with a 0.1 µF capacitor; continuous current ±50 mA max."
      }
    ],
    "provenance": {
      "extractor": "extract_pins 0.2",
      "factory_chain": {
        "factory": "2.0.0",
        "extractor": "extract_pins 0.2",
        "primary_model": "claude-sonnet-4-6",
        "primary_mode": "text+vision",
        "consensus_model": "claude-opus-4-7",
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [
          "vision extraction: provenance cannot be text-verified; needs consensus"
        ],
        "pages_sent": 28,
        "cost_usd": 0.5742,
        "at": "2026-09-18T00:59:58"
      },
      "datasheet": {
        "url": "https://www.ti.com/lit/ds/symlink/sn74hct138.pdf",
        "pages": 28,
        "sha256": "0d754c91dca77706",
        "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": "sn74hct138dr.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": "sn74hct138dr-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": "13a435b553d1c2707b4b4b21decb22981c4edac959b2701486fedab6d02c6754",
        "checked": "2026-10-19",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "Texas Instruments",
      "Package": "SOIC-16",
      "Category": "Logic",
      "Pins": "16"
    }
  },
  "variants": [],
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "sn74hct138dr"
  ],
  "discovery_pitch": "SN74HCT138DR (Texas Instruments) 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",
    "sn74hct138dr.kicad_sym",
    "sn74hct138dr.kicad_mod",
    "sn74hct138dr.glb",
    "sn74hct138dr.step",
    "sn74hct138dr.lbr",
    "docs/hero.png",
    "docs/sn74hct138dr-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html"
  ],
  "visibility": {
    "public": true
  },
  "updated_at": "2026-09-25T07:13:16.756Z"
}