MCP4921 12-Bit SPI DAC

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  "schema_version": 1,
  "type": "component",
  "slug": "mcp4921",
  "title": "MCP4921 12-Bit SPI DAC",
  "brief": "Single-channel 12-bit voltage-output DAC with SPI and an external reference input.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "dac",
    "12-bit",
    "single",
    "spi",
    "external-reference",
    "microchip",
    "soic-8"
  ],
  "component": {
    "mpn": "MCP4921",
    "manufacturer": "Microchip",
    "package": "SOIC-8",
    "pin_count": 8,
    "category": "Analog",
    "subcategory": "Digital-to-Analog Converter",
    "datasheet": "https://ww1.microchip.com/downloads/en/DeviceDoc/22250A.pdf",
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    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "VDD",
        "type": "power_in",
        "description": "Positive supply voltage input, 2.7V to 5.5V (absolute max 6.5V). Bypass with 0.1 µF to VSS."
      },
      {
        "number": "2",
        "name": "CS",
        "type": "input",
        "description": "SPI chip-select (active low). Enables the serial interface; input register writes latch on rising edge."
      },
      {
        "number": "3",
        "name": "SCK",
        "type": "input",
        "description": "SPI serial clock input, up to 20 MHz. Data on SDI is sampled on the rising edge."
      },
      {
        "number": "4",
        "name": "SDI",
        "type": "input",
        "description": "SPI serial data input. 16-bit command word (config bits + DAC data) shifted in MSB-first."
      },
      {
        "number": "5",
        "name": "LDAC",
        "type": "input",
        "description": "Synchronous DAC latch (active low). Falling edge transfers both DAC input registers to the DAC output registers, updating VOUTA and VOUTB simultaneously. Tie low for asynchronous updates."
      },
      {
        "number": "6",
        "name": "VREF",
        "type": "input",
        "description": "External voltage reference input for DAC A. Unbuffered range 0 to VDD; buffered range 0.040 V to VDD−0.040 V. Input impedance ~165 kΩ (unbuffered)."
      },
      {
        "number": "7",
        "name": "VSS",
        "type": "power_in",
        "description": "Ground return / negative supply. Connect to system analog ground."
      },
      {
        "number": "8",
        "name": "VOUT",
        "type": "output",
        "description": "DAC channel A buffered analog output. Rail-to-rail, output swing 0.01 V to VDD−0.04 V, short-circuit current ~15 mA typ, slew rate 0.55 V/µs."
      }
    ],
    "provenance": {
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        "pages": 48,
        "sha256": "8c507a2bce321888",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 8,
        "described": 8,
        "cites_pages": true,
        "refuses_to_fabricate": true
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        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "07f46cff378d30e6c27dfd5a03092c795323f86d91c71fc7e743f4f418dc553a",
        "checked": "2026-10-07",
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  },
  "metadata": {
    "specs": {
      "Resolution": "12-bit, 1 channel",
      "Output": "Voltage output (buffered, rail-to-rail)",
      "Reference": "External (VREF pin), 1x or 2x gain",
      "Interface": "SPI (up to 20 MHz)",
      "Settling time": "4.5 us typ",
      "Supply voltage": "2.7 V to 5.5 V",
      "Operating temperature": "-40 C to 125 C"
    }
  },
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  "discovery_triggers": [
    "single DAC",
    "SPI DAC",
    "12-bit voltage output",
    "set-point generator"
  ],
  "discovery_pitch": "One 12-bit analog output over SPI with an external reference and selectable gain, the single-channel MCP4922.",
  "author": {
    "name": "Ray"
  },
  "dependencies": {},
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  "variants": [
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