main
Ray Set visibility: public 06d40eb 11d ago
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{
  "schema_version": 1,
  "type": "component",
  "slug": "a4447sljtr-t",
  "title": "A4447SLJTR-T",
  "brief": "Allegro MicroSystems, LLC DC-DC Converters, SOIC-8-EP. 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",
    "power management ics",
    "a4447sljtr-t",
    "factory-2.0.0",
    "extractor-text"
  ],
  "component": {
    "mpn": "A4447SLJTR-T",
    "manufacturer": "Allegro MicroSystems, LLC",
    "package": "SOIC-8-EP",
    "pin_count": 9,
    "category": "Power Management ICs",
    "subcategory": "DC-DC Converters",
    "datasheet": "https://datasheet.lcsc.com/datasheet/pdf/5225d5207997cf67206ffef24ccec1b6.pdf",
    "parts": {
      "symbol": "a4447sljtr-t.kicad_sym",
      "footprint": "a4447sljtr-t.kicad_mod",
      "model_3d": "a4447sljtr-t-hero.glb",
      "model_3d_plain": "a4447sljtr-t-etched.glb",
      "model_3d_step": "a4447sljtr-t-etched.step",
      "model_3d_step_plain": "a4447sljtr-t.step",
      "lbr": "a4447sljtr-t.lbr"
    },
    "distributor_links": {
      "lcsc": "C112017"
    },
    "distributor_check": {
      "checked_at": "2026-10-22T23:01:03Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": null,
        "status": "deferred",
        "error": "shared DigiKey quota guard: 711 calls left today"
      },
      "mouser": {
        "pn": null,
        "status": "quota"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "BOOT",
        "type": "passive",
        "description": "Gate drive boost node, connected to the LX node through an external bootstrap capacitor (CBOOT 0.01 µF in the typical application)."
      },
      {
        "number": "2",
        "name": "ENB",
        "type": "input",
        "description": "On/off control logic input: pulled low (below 1.0 V) to enable the output and start soft start, open circuit (2.0 to 7 V) disables the switcher."
      },
      {
        "number": "3",
        "name": "TSET",
        "type": "passive",
        "description": "Off-time setting pin: a resistor to ground sets the fixed off-time, with RTSET not smaller than 7.65 kΩ ±2%."
      },
      {
        "number": "4",
        "name": "GND",
        "type": "power_in",
        "description": "Ground."
      },
      {
        "number": "5",
        "name": "FB",
        "type": "input",
        "description": "Feedback input for the adjustable regulator, regulated to 0.8 V (±2%) from the output resistor divider."
      },
      {
        "number": "6",
        "name": "VBIAS",
        "type": "power_in",
        "description": "Bias supply input, connected to VOUT when the VOUT target is between 3.3 and 5 V (absolute maximum 7 V), otherwise left open or fed from an external source."
      },
      {
        "number": "7",
        "name": "LX",
        "type": "output",
        "description": "Buck switching node connecting to the external inductor and catch diode."
      },
      {
        "number": "8",
        "name": "VIN",
        "type": "power_in",
        "description": "Supply input, 8 to 50 V operating range with 50 V absolute maximum."
      },
      {
        "number": "9",
        "name": "PAD",
        "type": "passive",
        "description": "Exposed thermal pad on the bottom, to be soldered to a ground copper area with thermal vias for heat dissipation."
      }
    ],
    "provenance": {
      "extractor": "extract_pins 0.3",
      "factory_chain": {
        "factory": "2.0.0",
        "extractor": "extract_pins 0.3",
        "primary_model": "claude-sonnet-5-5",
        "primary_mode": "text",
        "consensus_model": "claude-sonnet-5-5",
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [
          "extractor flagged: The datasheet's terminal list does not number or describe the exposed pad. The pinout diagram only l; The BOOT pin type and its connection are inferred. The datasheet says only 'Gate drive boost node' a; The VBIAS pin type is inferred from its function as a bias supply input. It can also be left open, a"
        ],
        "pages_sent": 12,
        "cost_usd": 0.1042,
        "at": "2026-10-22T23:00:50"
      },
      "datasheet": {
        "url": "https://datasheet.lcsc.com/datasheet/pdf/5225d5207997cf67206ffef24ccec1b6.pdf",
        "pages": 12,
        "sha256": "16a3d24d2c6d99ee",
        "source_tier": "lcsc"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 9,
        "described": 9,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
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        "seat": "z = 0",
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        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "2d6f7e774e8143e3320cbd59eb5be9f3b7864614644e3b072006e1eb05fb7fa6",
        "checked": "2026-10-22",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
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        "footprint_binding": "identity",
        "sha256": "323bcee74fffaaee397cae94ecdb7af6e37e011b0c24a60d81b606c4f43356be",
        "checked": "2026-10-22",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "Allegro MicroSystems, LLC",
      "Package": "SOIC-8-EP",
      "Category": "Power Management ICs",
      "Pins": "9"
    },
    "appearance": {
      "contacts": {
        "quote": "the VOUT node to be located as close as practical to the A4447 (U1). Thermal conduction from the A4447 is enhanced by direct contact of its exposed thermal pad to the smaller ground area under the A44",
        "page": 9,
        "doc": "ds.pdf",
        "material": "copper"
      },
      "version": 1,
      "datasheet_sha256": "16a3d24d2c6d99eece6eeebc1e419eee293387f26578eaa95b23a655609e6281"
    },
    "characteristics": {
      "version": 1,
      "source": "datasheet",
      "datasheet_sha256": "16a3d24d2c6d99eece6eeebc1e419eee293387f26578eaa95b23a655609e6281",
      "rows": [
        {
          "name": "VIN Supply Voltage",
          "symbol": "VIN",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 50,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "VBIAS Input Voltage",
          "symbol": "VBIAS",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": -0.3,
          "typ": null,
          "max": 7,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "SW Switching Voltage",
          "symbol": "VS",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": -1,
          "typ": null,
          "max": null,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "ENB Input Voltage Range",
          "symbol": "VENB",
          "kind": "absolute_maximum",
          "unit": "V",
          "min": -0.3,
          "typ": null,
          "max": 7,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Operating Ambient Temperature Range",
          "symbol": "TA",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": -20,
          "typ": null,
          "max": 85,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Junction Temperature",
          "symbol": "TJ(max)",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": null,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Storage Temperature",
          "symbol": "Tstg",
          "kind": "absolute_maximum",
          "unit": "°C",
          "min": -55,
          "typ": null,
          "max": 150,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Package Thermal Resistance (Junction to Ambient)",
          "symbol": "RθJA",
          "kind": "thermal",
          "unit": "ºC/W",
          "min": null,
          "typ": 35,
          "max": null,
          "conditions": "On 4-layer PCB based on JEDEC standard",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Package Thermal Resistance (Junction to Ambient)",
          "symbol": "RθJA",
          "kind": "thermal",
          "unit": "ºC/W",
          "min": null,
          "typ": 62,
          "max": null,
          "conditions": "On 2-layer generic test PCB with 0.8 in.2 of copper area each side",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "Package Thermal Resistance (Junction to Pad)",
          "symbol": "RθJP",
          "kind": "thermal",
          "unit": "ºC/W",
          "min": null,
          "typ": 2,
          "max": null,
          "conditions": "",
          "source_page": 2,
          "source": "datasheet"
        },
        {
          "name": "VIN Quiescent Current",
          "symbol": "IVIN(Q)",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 0.9,
          "max": 1.35,
          "conditions": "VENB = LOW, IOUT = 0 mA, VIN = 42 V, VBIAS = VOUT",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "VIN Quiescent Current",
          "symbol": "IVIN(Q)",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 4.4,
          "max": 6.35,
          "conditions": "VENB = LOW, IOUT = 0 mA, VIN = 42 V, VBIAS < 3 V",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "VIN Quiescent Current",
          "symbol": "IVIN(Q)",
          "kind": "electrical",
          "unit": "µA",
          "min": null,
          "typ": null,
          "max": 100,
          "conditions": "VENB = HIGH",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "VBIAS Input Current",
          "symbol": "IBIAS",
          "kind": "electrical",
          "unit": "mA",
          "min": null,
          "typ": 3.5,
          "max": 5,
          "conditions": "VBIAS = VOUT",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Fixed Off-Time Proportion",
          "symbol": "toff",
          "kind": "electrical",
          "unit": "%",
          "min": -15,
          "typ": null,
          "max": 15,
          "conditions": "Based on calculated value",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Feedback Voltage",
          "symbol": "VFB",
          "kind": "electrical",
          "unit": "V",
          "min": 0.784,
          "typ": 0.8,
          "max": 0.816,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Output Voltage Regulation",
          "symbol": "VOUT",
          "kind": "electrical",
          "unit": "%",
          "min": -3,
          "typ": null,
          "max": 3,
          "conditions": "IOUT = 0 mA to 2 A",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Feedback Input Bias Current",
          "symbol": "IFB",
          "kind": "electrical",
          "unit": "nA",
          "min": -400,
          "typ": -100,
          "max": 100,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Soft Start Time",
          "symbol": "tss",
          "kind": "timing",
          "unit": "ms",
          "min": 5,
          "typ": 10,
          "max": 15,
          "conditions": "",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Buck Switch Current Limit",
          "symbol": "ICL",
          "kind": "electrical",
          "unit": "A",
          "min": 2.2,
          "typ": null,
          "max": 3,
          "conditions": "VFB > 0.4 V",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Buck Switch Current Limit",
          "symbol": "ICL",
          "kind": "electrical",
          "unit": "A",
          "min": 0.5,
          "typ": null,
          "max": 1.2,
          "conditions": "VFB < 0.4 V",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "ENB Open Circuit Voltage",
          "symbol": "VOC",
          "kind": "electrical",
          "unit": "V",
          "min": 2,
          "typ": null,
          "max": 7,
          "conditions": "Output disabled",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "ENB Input Voltage Threshold",
          "symbol": "VENB(0)",
          "kind": "electrical",
          "unit": "V",
          "min": null,
          "typ": null,
          "max": 1,
          "conditions": "LOW level input (Logic 0), output enabled",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "ENB Input Current",
          "symbol": "IENB(0)",
          "kind": "electrical",
          "unit": "µA",
          "min": -10,
          "typ": null,
          "max": -1,
          "conditions": "VENB = 0 V",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "VIN Undervoltage Threshold",
          "symbol": "VUVLO",
          "kind": "electrical",
          "unit": "V",
          "min": 6.6,
          "typ": 6.9,
          "max": 7.2,
          "conditions": "VIN rising",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "VIN Undervoltage Hysteresis",
          "symbol": "VUVLO(hys)",
          "kind": "electrical",
          "unit": "V",
          "min": 0.7,
          "typ": null,
          "max": 1.1,
          "conditions": "VIN falling",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Buck Switch On Resistance",
          "symbol": "RDS(on)",
          "kind": "electrical",
          "unit": "mΩ",
          "min": null,
          "typ": 450,
          "max": null,
          "conditions": "TA = 25°C, IOUT = 2 A",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Buck Switch On Resistance",
          "symbol": "RDS(on)",
          "kind": "electrical",
          "unit": "mΩ",
          "min": null,
          "typ": 650,
          "max": null,
          "conditions": "TA = 125°C, IOUT = 2 A",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Thermal Shutdown Temperature",
          "symbol": "TJTSD",
          "kind": "electrical",
          "unit": "°C",
          "min": null,
          "typ": 165,
          "max": null,
          "conditions": "Temperature increasing",
          "source_page": 4,
          "source": "datasheet"
        },
        {
          "name": "Thermal Shutdown Hysteresis",
          "symbol": "TJTSD(hys)",
          "kind": "electrical",
          "unit": "°C",
          "min": null,
          "typ": 15,
          "max": null,
          "conditions": "Recovery = TJTSD – TJTSD(hys)",
          "source_page": 4,
          "source": "datasheet"
        }
      ]
    }
  },
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  "discovery_triggers": [
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  "discovery_pitch": "A4447SLJTR-T (Allegro MicroSystems, LLC) component page: datasheet pinout, KiCad symbol, footprint and 3D.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
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