ADS1220 24-Bit ADC

{
  "schema_version": 1,
  "type": "component",
  "slug": "ads1220",
  "title": "ADS1220 24-Bit ADC",
  "brief": "24-bit delta-sigma ADC with PGA, two differential inputs, and an on-chip temperature sensor.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "adc",
    "delta-sigma",
    "24-bit",
    "pga",
    "spi",
    "ti",
    "tssop-16"
  ],
  "component": {
    "mpn": "ADS1220",
    "manufacturer": "Texas Instruments",
    "package": "TSSOP-16",
    "pin_count": 17,
    "category": "Analog",
    "subcategory": "Analog-to-Digital Converter",
    "datasheet": "https://www.ti.com/lit/ds/symlink/ads1220.pdf",
    "parts": {
      "symbol": "ads1220.kicad_sym",
      "footprint": "ads1220.kicad_mod",
      "model_3d": "ads1220-etched.glb",
      "model_3d_plain": "ads1220.glb",
      "lbr": "ads1220.lbr",
      "model_3d_step": "ads1220-etched.step",
      "model_3d_step_plain": "ads1220.step"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "CLK",
        "type": "input",
        "description": "External clock source input. Connect to DGND to select the internal 2% accurate oscillator."
      },
      {
        "number": "2",
        "name": "DGND",
        "type": "power_in",
        "description": "Digital ground return for DVDD (2.3V-5.5V analog+digital operation)."
      },
      {
        "number": "3",
        "name": "AVSS",
        "type": "power_in",
        "description": "Negative analog power supply. Ground for single-supply operation (AVDD - AVSS in the 2.3V-5.5V range)."
      },
      {
        "number": "4",
        "name": "AIN3/REFN1",
        "type": "input",
        "description": "Analog input 3, or negative reference input 1 (REFN1) when the second reference input pair is selected. Internal low-side power switch is connected between AIN3/REFN1 and AVSS for burnout current-source biasing."
      },
      {
        "number": "5",
        "name": "AIN2",
        "type": "input",
        "description": "Analog input 2. Selectable via internal input multiplexer for single-ended or differential ADC conversion."
      },
      {
        "number": "6",
        "name": "REFN0",
        "type": "input",
        "description": "Negative reference input 0 for the external reference input pair (VREF = REFP0 - REFN0)."
      },
      {
        "number": "7",
        "name": "REFP0",
        "type": "input",
        "description": "Positive reference input 0 for the external reference input pair (VREF = REFP0 - REFN0)."
      },
      {
        "number": "8",
        "name": "AIN1",
        "type": "input",
        "description": "Analog input 1. Selectable via internal input multiplexer for single-ended or differential ADC conversion."
      },
      {
        "number": "9",
        "name": "AIN0/REFP1",
        "type": "input",
        "description": "Analog input 0, or positive reference input 1 (REFP1) when the second reference input pair is selected in the VREF register field."
      },
      {
        "number": "10",
        "name": "AVDD",
        "type": "power_in",
        "description": "Positive analog power supply, 2.3V-5.5V referenced to AVSS. Connect a 100 nF (or larger) decoupling capacitor to AVSS."
      },
      {
        "number": "11",
        "name": "DVDD",
        "type": "power_in",
        "description": "Positive digital power supply, 2.3V-5.5V referenced to DGND. Connect a 100 nF (or larger) decoupling capacitor to DGND."
      },
      {
        "number": "12",
        "name": "DRDY",
        "type": "output",
        "description": "Data-ready output, active low. Falls when a new ADC conversion result is available. Leave unconnected or tie to DVDD through a weak pull-up if not used."
      },
      {
        "number": "13",
        "name": "DOUT/DRDY",
        "type": "output",
        "description": "SPI serial data output combined with data-ready indication (active low). Data is shifted out on SCLK edges during a READ command; the pin also pulses low to signal new conversion data."
      },
      {
        "number": "14",
        "name": "DIN",
        "type": "input",
        "description": "SPI serial data input (MOSI). Latches command/register data on SCLK edges into the ADS1220."
      },
      {
        "number": "15",
        "name": "SCLK",
        "type": "input",
        "description": "SPI serial clock input (mode 1: CPOL=0, CPHA=1). Clocks data in on DIN and out on DOUT/DRDY."
      },
      {
        "number": "16",
        "name": "CS",
        "type": "input",
        "description": "SPI chip select input, active low. Enables the serial interface when driven low. Connect to DGND if the device is the only device on the SPI bus and CS is not otherwise used."
      },
      {
        "number": "PAD",
        "name": "PAD",
        "type": "passive",
        "description": "Thermal/exposed pad on the underside of the VQFN package. Do not connect, or connect only to AVSS. Not present on the TSSOP variant."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://www.ti.com/lit/ds/symlink/ads1220.pdf",
        "pages": 80,
        "sha256": "ba264d1644fe9de6",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 17,
        "described": 17,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "ads1220.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.4,
          5.0,
          1.1
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "6ad5e98224d02a427d9a6b929a28dbc158b9925fba5adec12db05079f1016948",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "ads1220-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.4,
          5.0,
          1.1
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "4b25f117c7a01a6379a0e6d7f50afc12ce0316d33f6e10073755390bc0cffe31",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Resolution": "24 bits",
      "Architecture": "Delta-sigma",
      "Data rate": "20 SPS to 2 kSPS",
      "Inputs": "2 differential / 4 single-ended, multiplexed",
      "PGA gain": "1 to 128 V/V",
      "Reference": "Internal 2.048 V, or external",
      "Interface": "SPI-compatible",
      "Supply": "2.3 V to 5.5 V (AVDD), 2.3 V to 5.5 V (DVDD)",
      "Operating temperature": "-40 C to 125 C"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "precision ADC",
    "load cell",
    "RTD measurement",
    "thermocouple front end",
    "bridge sensor"
  ],
  "discovery_pitch": "A small-footprint 24-bit ADC with a built-in PGA and reference for weigh scales, RTDs, and thermocouples over SPI.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "ads1220.kicad_sym",
    "ads1220.kicad_mod",
    "ads1220.glb",
    "ads1220.lbr",
    "docs/hero.png",
    "docs/ads1220-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "ads1220-etched.step"
  ]
}