LM317

{
  "schema_version": 1,
  "type": "component",
  "slug": "lm317",
  "title": "LM317",
  "brief": "TI 3-pin adjustable positive linear regulator, TO-220. 1.5 A, 1.25-37 V output. Datasheet-verified.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "regulator",
    "linear",
    "adjustable",
    "to-220",
    "texas-instruments"
  ],
  "component": {
    "mpn": "LM317",
    "manufacturer": "Texas Instruments",
    "package": "TO-220",
    "pin_count": 3,
    "category": "Power Management",
    "subcategory": "Adjustable linear regulator",
    "datasheet": "https://www.ti.com/lit/ds/symlink/lm317.pdf",
    "parts": {
      "symbol": "lm317.kicad_sym",
      "footprint": "lm317.kicad_mod",
      "model_3d": "lm317-etched.glb",
      "model_3d_plain": "lm317.glb",
      "lbr": "lm317.lbr",
      "model_3d_step": "lm317-etched.step",
      "model_3d_step_plain": "lm317.step"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "ADJ",
        "type": "input",
        "description": "Adjustment pin. Ties to the midpoint of the external R1/R2 divider between OUTPUT and GND to program VOUT = 1.25V x (1 + R2/R1) + I_ADJ x R2. Internal reference holds this pin at 1.25V below OUTPUT. Typical adjustment-pin current is 50 μA (100 μA max)."
      },
      {
        "number": "2",
        "name": "OUT",
        "type": "power_out",
        "description": "Regulated output. Delivers up to 1.5A over VOUT = 1.25V to 37V (VIN-VOUT differential 3V to 40V). Also electrically bonded to the package TAB for heatsinking. Optional 1 μF output capacitor improves transient response."
      },
      {
        "number": "3",
        "name": "IN",
        "type": "power_in",
        "description": "Unregulated input supply. Recommended 3V to 40V above VOUT (absolute max input-to-output differential 40V). Add a 0.1 μF input bypass if the device sits more than 6 inches from the input filter capacitors."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://www.ti.com/lit/ds/symlink/lm317.pdf",
        "pages": 44,
        "sha256": "323ec64a58515090",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 3,
        "described": 3,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "lm317.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "body on z = 0, through-hole leads below",
        "extents_mm": [
          10.25,
          4.455,
          28.525
        ],
        "zmin_mm": -9.75,
        "centre_offset_mm": 0.932,
        "footprint_binding": "identity",
        "sha256": "7cb065d935df5771f0ba6e48ddd180863a121af76483dad7f18e667a7b68204a",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "lm317-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "body on z = 0, through-hole leads below",
        "extents_mm": [
          10.25,
          4.455,
          28.525
        ],
        "zmin_mm": -9.75,
        "centre_offset_mm": 0.932,
        "footprint_binding": "identity",
        "sha256": "92dda4651d493bfe96010a516aed1c91c6d1f3e45b28794eea0ee7ce83eb093d",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Type": "Adjustable positive linear regulator",
      "Output voltage": "1.25-37 V (VREF 1.25 V)",
      "Output current": "1.5 A",
      "Input voltage": "up to 40 V (VIN-VOUT <= 40 V)",
      "Dropout": "~2 V typ",
      "Protection": "Current limit + thermal shutdown",
      "Package": "TO-220",
      "Body (L×W×H)": "10.3 × 4.6 × 15.9 mm (TO-220)"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "lm317",
    "adjustable voltage regulator",
    "variable linear regulator",
    "1.25v to 37v regulator"
  ],
  "discovery_pitch": "LM317 3-pin adjustable positive linear voltage regulator (TO-220) with datasheet-verified pinout, KiCad symbol/footprint/3D, and full provenance.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
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    "README.md",
    "lm317.kicad_sym",
    "lm317.kicad_mod",
    "lm317.glb",
    "lm317.lbr",
    "docs/hero.png",
    "docs/lm317-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "lm317-etched.step"
  ],
  "variants": [
    {
      "mpn": "LM317T (TO-220)",
      "kind": "packaging"
    },
    {
      "mpn": "LM317KTTR (TO-263)",
      "kind": "packaging"
    }
  ]
}