MCP3421 18-Bit I2C ADC

{
  "schema_version": 1,
  "type": "component",
  "slug": "mcp3421",
  "title": "MCP3421 18-Bit I2C ADC",
  "brief": "18-bit delta-sigma ADC with I2C, on-chip reference and PGA, in a tiny SOT-23-6.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "adc",
    "delta-sigma",
    "18-bit",
    "i2c",
    "pga",
    "microchip",
    "sot-23-6"
  ],
  "component": {
    "mpn": "MCP3421",
    "manufacturer": "Microchip",
    "package": "SOT-23-6",
    "pin_count": 6,
    "category": "Analog",
    "subcategory": "Analog-to-Digital Converter",
    "datasheet": "https://ww1.microchip.com/downloads/en/DeviceDoc/22003e.pdf",
    "parts": {
      "symbol": "mcp3421.kicad_sym",
      "footprint": "mcp3421.kicad_mod",
      "model_3d": "mcp3421-etched.glb",
      "model_3d_plain": "mcp3421.glb",
      "model_3d_step": "mcp3421-etched.step",
      "model_3d_step_plain": "mcp3421.step",
      "lbr": "mcp3421.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "VIN+",
        "type": "input",
        "description": "Positive differential analog input. Absolute voltage range VSS-0.3 V to VDD+0.3 V. Differential input range ±2.048 V/PGA; common-mode input impedance ~25 MΩ."
      },
      {
        "number": "2",
        "name": "VSS",
        "type": "power_in",
        "description": "Ground / analog return. Tie to the analog ground plane through a low-impedance connection."
      },
      {
        "number": "3",
        "name": "SCL",
        "type": "input",
        "description": "I2C serial clock input (slave). Accepts standard, Fast, and High-Speed mode clocks; data on SDA is shifted on SCL edges."
      },
      {
        "number": "4",
        "name": "SDA",
        "type": "bidirectional",
        "description": "I2C bidirectional serial data. Open-drain; requires external pull-up. VIH ≥ 0.7·VDD, VIL ≤ 0.3·VDD, VOL ≤ 0.4 V at 3 mA."
      },
      {
        "number": "5",
        "name": "VDD",
        "type": "power_in",
        "description": "Positive supply, 2.7 V to 5.5 V. Bypass with 0.1 µF ceramic (and additional 10 µF tantalum recommended) to VSS."
      },
      {
        "number": "6",
        "name": "VIN-",
        "type": "input",
        "description": "Negative differential analog input. Tie to VSS for single-ended operation. Absolute voltage range VSS-0.3 V to VDD+0.3 V."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://ww1.microchip.com/downloads/en/DeviceDoc/22003e.pdf",
        "pages": 42,
        "sha256": "5249b67ed71256bc",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 6,
        "described": 6,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "mcp3421.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          2.8,
          2.9,
          1.55
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "c9fe686b4d1b56927a41fa84a9bc1efb61d8a45a123a3db43bcaa05c2891d635",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "mcp3421-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          2.8,
          2.9,
          1.55
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "e75824a678ce8fce37ca9639619c25e076f14fdd44e41da12493d61b0bbe8319",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Resolution": "12/14/16/18-bit (selectable)",
      "Architecture": "Delta-sigma",
      "Inputs": "1 differential",
      "Reference": "Internal 2.048 V",
      "PGA gain": "1x, 2x, 4x, 8x",
      "Interface": "I2C",
      "Supply voltage": "2.7 V to 5.5 V",
      "Operating temperature": "-40 C to 125 C"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "18-bit ADC",
    "I2C ADC",
    "precision measurement",
    "single-channel ADC",
    "tiny ADC"
  ],
  "discovery_pitch": "An 18-bit ADC with a built-in reference and PGA over I2C, in a 6-pin package for precision single-channel measurement.",
  "author": {
    "name": "Ray"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "mcp3421.kicad_sym",
    "mcp3421.kicad_mod",
    "mcp3421.glb",
    "mcp3421.step",
    "mcp3421.lbr",
    "docs/hero.png",
    "docs/mcp3421-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "mcp3421-etched.step"
  ],
  "variants": [
    {
      "mpn": "MCP3421A0T",
      "kind": "unknown"
    },
    {
      "mpn": "MCP3421A1T",
      "kind": "unknown"
    },
    {
      "mpn": "MCP3421A2T",
      "kind": "unknown"
    },
    {
      "mpn": "MCP3421A3T",
      "kind": "unknown"
    }
  ]
}