L7908 Negative Voltage Regulator

{
  "schema_version": 1,
  "type": "component",
  "slug": "l7908",
  "title": "L7908 Negative Voltage Regulator",
  "brief": "Fixed -8 V negative-voltage linear regulator, up to 1.5 A, in the L79xx series.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "regulator",
    "linear",
    "negative",
    "fixed",
    "pmic",
    "st",
    "to-220"
  ],
  "component": {
    "mpn": "L7908",
    "manufacturer": "STMicroelectronics",
    "package": "TO-220",
    "pin_count": 3,
    "category": "Power Management",
    "subcategory": "Linear Regulator (LDO)",
    "datasheet": "https://www.st.com/resource/en/datasheet/l79.pdf",
    "parts": {
      "symbol": "l7908.kicad_sym",
      "footprint": "l7908.kicad_mod",
      "model_3d": "l7908-etched.glb",
      "model_3d_plain": "l7908.glb",
      "model_3d_step": "l7908-etched.step",
      "model_3d_step_plain": "l7908.step",
      "lbr": "l7908.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "GND",
        "type": "power_in",
        "description": "Common/ground return. For the L79 negative regulator family the ground pin is pin 1 on TO-220 / TO-220FP (this differs from the L78 positive-regulator pinout)."
      },
      {
        "number": "2",
        "name": "IN",
        "type": "power_in",
        "description": "Unregulated negative input voltage. Recommended operating range for the -8 V version is roughly -11 V to -23 V (V_I max abs = -35 V). A 2.2 µF bypass capacitor to GND is required close to this pin."
      },
      {
        "number": "3",
        "name": "OUT",
        "type": "power_out",
        "description": "Regulated -8 V output, up to 1.5 A with adequate heat sinking. Typical dropout 1.1 V at 1 A. A 1 µF output capacitor to GND is required for loop stability."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://www.st.com/resource/en/datasheet/l79.pdf",
        "pages": 29,
        "sha256": "6bdb1e0a1c61a10d",
        "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": "l7908.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": "l7908-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": "b95c1ce4c1b953261c37536675e13a1ea97a2ffa2038bad6e6c41e67cad480b8",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Type": "Fixed negative linear regulator",
      "Output voltage": "-8 V",
      "Output current": "Up to 1.5 A (with heatsink)",
      "Line/load regulation": "Internally set",
      "Package": "TO-220 (3-lead)",
      "Operating temperature": "0 C to 125 C (junction)"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "negative voltage regulator",
    "-8V rail",
    "split supply",
    "dual rail regulator"
  ],
  "discovery_pitch": "A fixed -8 V regulator for the negative rail of a split supply, the negative counterpart to the L7808.",
  "author": {
    "name": "Ray"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
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    "README.md",
    "l7908.kicad_sym",
    "l7908.kicad_mod",
    "l7908.glb",
    "l7908.step",
    "l7908.lbr",
    "docs/hero.png",
    "docs/l7908-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "l7908-etched.step"
  ],
  "variants": [
    {
      "mpn": "L7908CV",
      "kind": "unknown"
    },
    {
      "mpn": "L7908ACV",
      "kind": "unknown"
    },
    {
      "mpn": "L7908CP",
      "kind": "unknown"
    },
    {
      "mpn": "L7908ACP",
      "kind": "unknown"
    },
    {
      "mpn": "L7908CD2T",
      "kind": "unknown"
    },
    {
      "mpn": "L7908ACD2T",
      "kind": "unknown"
    }
  ]
}