ab1805-t3

{
  "slug": "ab1805-t3",
  "version": "0.1.0",
  "type": "component",
  "description": "Abracon LLC Real-time Clocks (RTC), QFN-16(3x3). Datasheet-verified pinout, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "rtc",
    "ab1805-t3"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "ab1805-t3.kicad_sym",
    "ab1805-t3.kicad_mod",
    "ab1805-t3.glb",
    "ab1805-t3.step",
    "ab1805-t3.lbr",
    "docs/hero.png",
    "docs/ab1805-t3-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "ab1805-t3-etched.step"
  ],
  "visibility": {
    "public": true
  },
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "component": {
    "mpn": "AB1805-T3",
    "manufacturer": "Abracon LLC",
    "package": "QFN-16(3x3)",
    "pin_count": 17,
    "category": "Real-time Clocks (RTC)",
    "parts": {
      "symbol": "ab1805-t3.kicad_sym",
      "footprint": "ab1805-t3.kicad_mod",
      "model_3d": "ab1805-t3-etched.glb",
      "model_3d_plain": "ab1805-t3.glb",
      "model_3d_step": "ab1805-t3-etched.step",
      "model_3d_step_plain": "ab1805-t3.step",
      "lbr": "ab1805-t3.lbr"
    },
    "pins": [
      {
        "number": "1",
        "name": "nRST",
        "type": "output",
        "description": "Active-low external reset output (open-drain). Requires an external pull-up when used; polarity is set by the RSP register bit (defaults to active-low on POR). Can be left floating if unused."
      },
      {
        "number": "2",
        "name": "WDI",
        "type": "input",
        "description": "Watchdog Timer reset input. Can also generate the External 2 interrupt (polarity via EX2P, enabled by EX2E); state readable in the WDIN bit. No internal pull; must be tied to VCC or VSS if unused to avoid extra current."
      },
      {
        "number": "3",
        "name": "nEXTR",
        "type": "input",
        "description": "Active-low external reset input. When low with RS1E set, drives nRST to its asserted state. No internal pull; must be tied to VCC or VSS if unused."
      },
      {
        "number": "4",
        "name": "PSW/nIRQ2",
        "type": "output",
        "description": "Secondary interrupt / power-switch output (open-drain). Selectable via OUT2S: OUTB value, SQW, /IRQ, /AIRQ, TIRQ, or a ~1 Ω power-switch to VSS (~50 mA continuous, 150 mA 1 s pulse) when PWR2 is set. May be left floating if unused."
      },
      {
        "number": "5",
        "name": "VBAT",
        "type": "power_in",
        "description": "Battery-backup power input (1.5-3.6 V). Also feeds the internal analog comparator input. Tie directly to VSS if no backup battery is used."
      },
      {
        "number": "6",
        "name": "SDA",
        "type": "bidirectional",
        "description": "I2C serial data line (up to 400 kHz). Open-drain; requires an external pull-up resistor to VCC."
      },
      {
        "number": "7",
        "name": "SCL",
        "type": "input",
        "description": "I2C serial clock input (up to 400 kHz). Requires an external pull-up resistor to VCC."
      },
      {
        "number": "8",
        "name": "CLKOUT/nIRQ3",
        "type": "output",
        "description": "Push-pull square-wave / clock / interrupt 3 output. Selectable to drive the OUT bit value or the SQW output when SQWE is set."
      },
      {
        "number": "9",
        "name": "VSS",
        "type": "power_in",
        "description": "Ground return. Must be connected together with the thermal pad (pin 17)."
      },
      {
        "number": "10",
        "name": "EXTI",
        "type": "input",
        "description": "External interrupt input. Generates the External 1 interrupt (polarity via EX1P, enabled by EX1E); state readable in the EXIN bit. No internal pull; must be tied to VCC or VSS if unused to avoid extra current."
      },
      {
        "number": "11",
        "name": "FOUT/nIRQ",
        "type": "output",
        "description": "Primary interrupt / function output (open-drain, requires external pull-up). Selectable via OUT1S: OUT bit, inverted combined IRQ, SQW output when SQWE is set, or inverted alarm interrupt AIRQ. Held low on power-up until the AB1805 exits reset and is accessible via the serial interface."
      },
      {
        "number": "12",
        "name": "nTIRQ",
        "type": "output",
        "description": "Active-low timer interrupt output (open-drain, only present on the I2C variant). Requires an external pull-up when used; may be left floating if unused."
      },
      {
        "number": "13",
        "name": "VCC",
        "type": "power_in",
        "description": "Primary system supply input (1.5-3.6 V; absolute max 3.8 V). Must be connected if a single supply is used."
      },
      {
        "number": "14",
        "name": "AF",
        "type": "passive",
        "description": "Autocalibration filter pin. Requires an external 47 pF ceramic capacitor from this pin to VSS for accurate Autocalibration-mode timing."
      },
      {
        "number": "15",
        "name": "XO",
        "type": "output",
        "description": "32.768 kHz crystal oscillator output. Integrated load capacitor and feedback resistor; connect directly to the crystal (no external caps required)."
      },
      {
        "number": "16",
        "name": "XI",
        "type": "input",
        "description": "32.768 kHz crystal oscillator input. Integrated load capacitor and feedback resistor; connect directly to the crystal (no external caps required)."
      },
      {
        "number": "17",
        "name": "VSS",
        "type": "power_in",
        "description": "Exposed thermal / ground pad on the bottom of the QFN-16 package. Must be connected to VSS."
      }
    ],
    "provenance": {
      "rebuilt": "component block rebuilt 2026-10-05 from this page's own README pinout table and .kicad_sym (pins cross-checked), no re-extraction"
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "distributor_links": {
      "lcsc": "C2649355",
      "digikey": "535-11932-2-ND",
      "mouser": "815-AB1805-T3"
    },
    "distributor_check": {
      "checked_at": "2026-10-05T18:51:07Z",
      "source": "Component Ocean /api/assign-pns + lcsc_map",
      "digikey": {
        "pn": "535-11932-2-ND",
        "status": "found"
      },
      "mouser": {
        "pn": "815-AB1805-T3",
        "status": "found"
      }
    },
    "models_3d": [
      {
        "file": "ab1805-t3.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          3.0,
          3.0,
          0.785
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "3eb81ffac423a66cdcfead8efe56401da171edaf1f2257049aad7b2d3900f6c8",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "ab1805-t3-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          3.0,
          3.0,
          0.785
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "9210ed26b544785f5e5e344567bde470a34fd774efbda61f978f3e06dde02724",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  }
}