A4950

{
  "schema_version": 1,
  "type": "component",
  "slug": "a4950",
  "title": "A4950",
  "brief": "Allegro full-bridge brushed DC motor driver, SOIC-8 with exposed pad. 8-40 V, 3.5 A peak, current limit. Datasheet-verified.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "driver",
    "motor-driver",
    "h-bridge",
    "brushed-dc",
    "soic-8",
    "allegro"
  ],
  "component": {
    "mpn": "A4950",
    "manufacturer": "Allegro MicroSystems",
    "package": "SOIC-8-EP",
    "pin_count": 9,
    "category": "Driver",
    "subcategory": "Brushed DC motor driver",
    "datasheet": "https://www.allegromicro.com/-/media/files/datasheets/a4950-datasheet.pdf",
    "parts": {
      "symbol": "a4950.kicad_sym",
      "footprint": "a4950.kicad_mod",
      "model_3d": "a4950-etched.glb",
      "model_3d_plain": "a4950.glb",
      "model_3d_step": "a4950-etched.step",
      "model_3d_step_plain": "a4950.step",
      "lbr": "a4950.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "GND",
        "type": "power_in",
        "description": "Device ground return. Should tie to the PCB star ground located directly under the exposed thermal pad."
      },
      {
        "number": "2",
        "name": "IN2",
        "type": "input",
        "description": "Logic input 2 for the full bridge. VIN(1) ≥ 2.0 V, VIN(0) ≤ 0.8 V, with internal ~50 kΩ pull-down. Combined with IN1 selects forward, reverse, brake, or coast/standby per the PWM Control Truth Table."
      },
      {
        "number": "3",
        "name": "IN1",
        "type": "input",
        "description": "Logic input 1 for the full bridge. VIN(1) ≥ 2.0 V, VIN(0) ≤ 0.8 V, with internal ~50 kΩ pull-down. Both inputs low for >1 ms enters Low Power Standby mode."
      },
      {
        "number": "4",
        "name": "VREF",
        "type": "input",
        "description": "Analog reference input that sets the PWM current-limit threshold. Valid range 0 to 5 V; peak trip current is ITripMAX = VREF / (10 × RS), where RS is the sense resistor on LSS."
      },
      {
        "number": "5",
        "name": "VBB",
        "type": "power_in",
        "description": "Load supply voltage input, 8 to 40 V operating range (40 V absolute max). Should be decoupled with a bulk electrolytic (~100 µF) in parallel with a ceramic (~0.22 µF) close to the pin."
      },
      {
        "number": "6",
        "name": "OUT1",
        "type": "output",
        "description": "DMOS full-bridge output 1 driving one side of the motor winding. Rated for up to ±3.5 A continuous (6 A transient <500 ns); absolute output voltage range −2 to 42 V."
      },
      {
        "number": "7",
        "name": "LSS",
        "type": "passive",
        "description": "Low-side source / sense-resistor return. External current-sense resistor RS is connected from LSS to ground for PWM current regulation. Sense voltage limit ±500 mV."
      },
      {
        "number": "8",
        "name": "OUT2",
        "type": "output",
        "description": "DMOS full-bridge output 2 driving the other side of the motor winding. Rated for up to ±3.5 A continuous (6 A transient <500 ns); absolute output voltage range −2 to 42 V."
      },
      {
        "number": "9",
        "name": "PAD",
        "type": "passive",
        "description": "Exposed thermal pad on the underside of the package. Solder to the PCB copper ground plane for enhanced thermal dissipation; typically connected to GND at the star ground point."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://www.allegromicro.com/-/media/files/datasheets/a4950-datasheet.pdf",
        "pages": 9,
        "sha256": "9878d992aa310a27",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 9,
        "described": 9,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "a4950.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.9,
          4.9,
          1.65
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "f1718a42c5ea007e8e2dd672ac39a1bb358ee4849bd53c42e21ce83e0e5df7a9",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "a4950-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.9,
          4.9,
          1.65
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "b5d4db3f136b96e086a92a7763cdc15d7b84e676649e054fded3789526548bcf",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Type": "Full-bridge brushed DC motor driver",
      "Supply (VBB)": "8-40 V",
      "Peak current": "3.5 A",
      "Control": "IN1 / IN2 (PWM)",
      "Current limit": "Fixed off-time (VREF + LSS sense)",
      "Protection": "UVLO, OCP, thermal",
      "Package": "SOIC-8 with exposed pad"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "a4950",
    "full bridge motor driver",
    "brushed dc h-bridge",
    "40v motor driver"
  ],
  "discovery_pitch": "Allegro A4950 full-bridge brushed DC motor driver (SOIC-8 EP) 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": [
    "page.json",
    "README.md",
    "a4950.kicad_sym",
    "a4950.kicad_mod",
    "a4950.glb",
    "a4950.step",
    "a4950.lbr",
    "docs/hero.png",
    "docs/a4950-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "a4950-etched.step"
  ]
}