SI4461-C2A-GMR

{
  "slug": "si4461-c2a-gmr",
  "version": "0.1.0",
  "type": "component",
  "description": "SILICON LABS RF Transceiver ICs, QFN-20-EP(4x4). Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "rf & radio",
    "si4461-c2a-gmr",
    "factory-2.0.0",
    "extractor-text"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "si4461-c2a-gmr.kicad_sym",
    "si4461-c2a-gmr.kicad_mod",
    "si4461-c2a-gmr.glb",
    "si4461-c2a-gmr.step",
    "si4461-c2a-gmr.lbr",
    "docs/hero.png",
    "docs/si4461-c2a-gmr-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "si4461-c2a-gmr-hero.glb",
    "si4461-c2a-gmr-hero.overlay.json",
    "si4461-c2a-gmr-etched.glb"
  ],
  "component": {
    "mpn": "SI4461-C2A-GMR",
    "manufacturer": "SILICON LABS",
    "package": "QFN-20-EP(4x4)",
    "pin_count": 21,
    "category": "RF & Radio",
    "subcategory": "RF Transceiver ICs",
    "datasheet": "https://datasheet.lcsc.com/datasheet/pdf/c9b3d6b38b5500d80adf50c8047d5f16.pdf",
    "parts": {
      "symbol": "si4461-c2a-gmr.kicad_sym",
      "footprint": "si4461-c2a-gmr.kicad_mod",
      "model_3d": "si4461-c2a-gmr-hero.glb",
      "model_3d_plain": "si4461-c2a-gmr-etched.glb",
      "model_3d_step": "si4461-c2a-gmr-etched.step",
      "model_3d_step_plain": "si4461-c2a-gmr.step",
      "lbr": "si4461-c2a-gmr.lbr"
    },
    "distributor_links": {
      "lcsc": "C2151525"
    },
    "distributor_check": {
      "checked_at": "2026-10-22T21:11:21Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": null,
        "status": "quota"
      },
      "mouser": {
        "pn": null,
        "status": "quota"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "SDN",
        "type": "input",
        "description": "Shutdown input, 0-VDD V digital; must be 0 in all modes except Shutdown, and when 1 the chip is completely shut down and register contents are lost."
      },
      {
        "number": "2",
        "name": "RXp",
        "type": "input",
        "description": "Differential RF input of the LNA; see application schematic for example matching network."
      },
      {
        "number": "3",
        "name": "RXn",
        "type": "input",
        "description": "Differential RF input of the LNA; see application schematic for example matching network."
      },
      {
        "number": "4",
        "name": "TX",
        "type": "output",
        "description": "Transmit output; PA output is open-drain so the L-C match must supply VDD (+3.3 VDC nominal) to this pin."
      },
      {
        "number": "5",
        "name": "NC",
        "type": "unconnected",
        "description": "Not connected internally to any circuitry; recommended to connect to GND per the reference design schematic."
      },
      {
        "number": "6",
        "name": "VDD",
        "type": "power_in",
        "description": "+1.8 to +3.8 V supply input to internal regulators; recommended +3.3 V."
      },
      {
        "number": "7",
        "name": "TXRAMP",
        "type": "output",
        "description": "Programmable bias output with ramp capability for external FET PA."
      },
      {
        "number": "8",
        "name": "VDD",
        "type": "power_in",
        "description": "+1.8 to +3.8 V supply input to internal regulators; recommended +3.3 V."
      },
      {
        "number": "9",
        "name": "GPIO0",
        "type": "bidirectional",
        "description": "General purpose digital I/O configurable via registers for functions such as microcontroller clock output, FIFO status, POR, wake-up timer, low battery detect, TRSW and antenna diversity control."
      },
      {
        "number": "10",
        "name": "GPIO1",
        "type": "bidirectional",
        "description": "General purpose digital I/O configurable via registers for functions such as microcontroller clock output, FIFO status, POR, wake-up timer, low battery detect, TRSW and antenna diversity control."
      },
      {
        "number": "11",
        "name": "nIRQ",
        "type": "output",
        "description": "Interrupt status output, set low on any interrupt event; no external pull-up required but may be desirable if multiple interrupt lines are connected."
      },
      {
        "number": "12",
        "name": "SCLK",
        "type": "input",
        "description": "Serial clock input, 0-VDD V digital, for the 4-line serial bus; data is clocked in on positive edge transitions."
      },
      {
        "number": "13",
        "name": "SDO",
        "type": "output",
        "description": "0-VDD V digital output providing serial readback of the internal control registers."
      },
      {
        "number": "14",
        "name": "SDI",
        "type": "input",
        "description": "Serial data input, 0-VDD V digital, for the 4-line serial bus."
      },
      {
        "number": "15",
        "name": "nSEL",
        "type": "input",
        "description": "Serial interface select input, 0-VDD V digital, providing select/enable for the 4-line serial bus."
      },
      {
        "number": "16",
        "name": "XOUT",
        "type": "output",
        "description": "Crystal oscillator output; connect to an external 25 to 32 MHz crystal, or leave floating when driving an external source on XIN."
      },
      {
        "number": "17",
        "name": "XIN",
        "type": "input",
        "description": "Crystal oscillator input; connect to an external 25 to 32 MHz crystal or to an external source."
      },
      {
        "number": "18",
        "name": "GND",
        "type": "power_in",
        "description": "Leave floating when using an XTAL per the reference design; when using a TCXO connect to TCXO GND, separate from the board reference ground plane."
      },
      {
        "number": "19",
        "name": "GPIO2",
        "type": "bidirectional",
        "description": "General purpose digital I/O configurable via registers for functions such as microcontroller clock output, FIFO status, POR, wake-up timer, low battery detect, TRSW and antenna diversity control."
      },
      {
        "number": "20",
        "name": "GPIO3",
        "type": "bidirectional",
        "description": "General purpose digital I/O configurable via registers for functions such as microcontroller clock output, FIFO status, POR, wake-up timer, low battery detect, TRSW and antenna diversity control."
      },
      {
        "number": "21",
        "name": "PADDLE_GND",
        "type": "power_in",
        "description": "Exposed paddle supplying RF and circuit ground for the entire chip; requires a good solder connection to the PCB ground plane."
      }
    ],
    "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 gives no number for the exposed paddle. '21' is an assumed designator for the PKG PADD; Pin 18 is labeled GND, but the description says to leave it floating with a crystal. It connects to ; The ordering table lists Si4461-C2A-GM with an (R) suffix for tape and reel. The package is describe",
          "2/21 pins cited to the wrong page (name found elsewhere): ['17:XIN@p45', '21:PADDLE_GND@p45']"
        ],
        "pages_sent": 12,
        "cost_usd": 0.1346,
        "at": "2026-10-22T21:11:11"
      },
      "datasheet": {
        "url": "https://datasheet.lcsc.com/datasheet/pdf/c9b3d6b38b5500d80adf50c8047d5f16.pdf",
        "pages": 53,
        "sha256": "8882300b5eda9509",
        "source_tier": "lcsc"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 21,
        "described": 21,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "si4461-c2a-gmr.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          4.0,
          4.0,
          0.77
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "c9476a1612023de37f27b4972110ab6ac6dc0eaf5ac48957a2e1c497650082a5",
        "checked": "2026-10-22",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "si4461-c2a-gmr-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          4.0,
          4.0,
          0.77
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "b2a1d78aab7af56fc268e25f8a740fee637abb9e8cf00deb61bb141e2705c297",
        "checked": "2026-10-22",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  }
}