MAX3221

{
  "schema_version": 1,
  "type": "component",
  "slug": "max3221",
  "title": "MAX3221",
  "brief": "ADI (Maxim) 1-driver 1-receiver RS-232 transceiver, SSOP-16. 3-5.5 V, charge-pump, auto-shutdown. Datasheet-verified.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "interface",
    "rs-232",
    "transceiver",
    "charge-pump",
    "ssop-16",
    "analog-devices"
  ],
  "component": {
    "mpn": "MAX3221",
    "manufacturer": "Analog Devices",
    "package": "SSOP-16",
    "pin_count": 16,
    "category": "Interface",
    "subcategory": "RS-232 transceiver",
    "datasheet": "https://www.analog.com/media/en/technical-documentation/data-sheets/MAX3221-MAX3243.pdf",
    "parts": {
      "symbol": "max3221.kicad_sym",
      "footprint": "max3221.kicad_mod",
      "model_3d": "max3221-etched.glb",
      "model_3d_plain": "max3221.glb",
      "model_3d_step": "max3221-etched.step",
      "model_3d_step_plain": "max3221.step",
      "lbr": "max3221.lbr"
    },
    "distributor_links": {},
    "pins": [
      {
        "number": "1",
        "name": "EN",
        "type": "input",
        "description": "Active-low receiver enable. Drive low for normal receiver operation; drive high to force R_OUT into high-Z. Logic threshold VIL=0.8V max, VIH=2.0V (3.3V) / 2.4V (5.0V)."
      },
      {
        "number": "2",
        "name": "C1+",
        "type": "passive",
        "description": "Positive terminal of the voltage-doubler charge-pump flying capacitor (C1). Typ 0.1µF at 3.3V, 0.047µF at 5.0V (Note 2)."
      },
      {
        "number": "3",
        "name": "V+",
        "type": "power_out",
        "description": "+5.5V output generated by the doubling charge pump. Bypass to GND with the reservoir capacitor C3 (0.1µF typ at 3.3V, 0.33µF at 5.0V)."
      },
      {
        "number": "4",
        "name": "C1-",
        "type": "passive",
        "description": "Negative terminal of the voltage-doubler charge-pump flying capacitor (C1)."
      },
      {
        "number": "5",
        "name": "C2+",
        "type": "passive",
        "description": "Positive terminal of the inverting charge-pump flying capacitor (C2). Typ 0.1µF at 3.3V, 0.33µF at 5.0V."
      },
      {
        "number": "6",
        "name": "C2-",
        "type": "passive",
        "description": "Negative terminal of the inverting charge-pump flying capacitor (C2)."
      },
      {
        "number": "7",
        "name": "V-",
        "type": "power_out",
        "description": "-5.5V output generated by the inverting charge pump. Bypass to GND with reservoir capacitor C4."
      },
      {
        "number": "8",
        "name": "R_IN",
        "type": "input",
        "description": "RS-232 receiver input. Accepts ±25V EIA/TIA-232 levels; typical input resistance 5kΩ (3-7kΩ). VIL ≈ 0.6-1.2V, VIH ≈ 1.5-2.4V, 0.3V typical hysteresis."
      },
      {
        "number": "9",
        "name": "R_OUT",
        "type": "tri_state",
        "description": "TTL/CMOS receiver output (inverted from R_IN). Three-state: high-Z in shutdown, when EN is high, or when the part is in AutoShutdown. VOL ≤ 0.4V at 1.6mA; VOH ≥ VCC-0.6V at -1.0mA."
      },
      {
        "number": "10",
        "name": "INVALID",
        "type": "output",
        "description": "Active-low valid-signal detector output. Low (asserted) while all receiver inputs are between -0.3V and +0.3V for ≥30µs (invalid RS-232 present); high when a valid RS-232 level (>+2.7V or <-2.7V) appears. Useful for DTR/RI monitoring."
      },
      {
        "number": "11",
        "name": "T_OUT",
        "type": "output",
        "description": "RS-232 transmitter output. Inverting driver to EIA/TIA-232 levels, ±5.0V typ swing into 3kΩ‖1000pF, short-circuit current ±35mA typ. High-Z in shutdown."
      },
      {
        "number": "12",
        "name": "FORCEON",
        "type": "input",
        "description": "Active-high override that keeps the transmitter and charge pumps on regardless of receiver-input activity (FORCEOFF must be high). See AutoShutdown truth table."
      },
      {
        "number": "13",
        "name": "T_IN",
        "type": "input",
        "description": "TTL/CMOS transmitter input. Drives the inverting RS-232 transmitter. VIL ≤ 0.8V, VIH ≥ 2.0V (3.3V) / 2.4V (5.0V)."
      },
      {
        "number": "14",
        "name": "GND",
        "type": "power_in",
        "description": "Device ground reference for logic and charge-pump return."
      },
      {
        "number": "15",
        "name": "VCC",
        "type": "power_in",
        "description": "+3.0V to +5.5V supply input. Bypass with 0.1µF to GND. Absolute max -0.3V to +6V."
      },
      {
        "number": "16",
        "name": "FORCEOFF",
        "type": "input",
        "description": "Active-low master shutdown. Drive low to disable transmitters and on-board power supply (overrides FORCEON and all AutoShutdown circuitry). Tie high for normal operation; can be tied to FORCEON as a single SHDN-style input."
      }
    ],
    "provenance": {
      "extractor": "ds2sf",
      "datasheet": {
        "url": "https://www.analog.com/media/en/technical-documentation/data-sheets/MAX3221-MAX3243.pdf",
        "pages": 16,
        "sha256": "4b10ea08c7155060",
        "source_tier": "mfr"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 16,
        "described": 16,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "max3221.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          7.8,
          6.2,
          2.1
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "d0e11e46aeca5dbaa5c4bb538f3f4899761267cabdeba6486325ae9e979c03ef",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "max3221-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          7.8,
          6.2,
          2.1
        ],
        "zmin_mm": 0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "6068db4f0fa7467161c7ffe04589501a1704934fb09feb5570061b35fa66364b",
        "checked": "2026-10-07",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Type": "RS-232 transceiver (1 driver, 1 receiver)",
      "Supply": "3-5.5 V",
      "Line levels": "RS-232 via on-chip charge pump",
      "Power control": "Auto-shutdown, FORCEON / FORCEOFF",
      "Status": "INVALID (valid-signal detect)",
      "Data rate": "Up to 250 kbps",
      "Package": "SSOP-16"
    }
  },
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "max3221",
    "rs-232 transceiver",
    "3.3v rs232",
    "single channel rs232"
  ],
  "discovery_pitch": "ADI MAX3221 1-driver 1-receiver RS-232 transceiver (SSOP-16) with datasheet-verified pinout, KiCad symbol/footprint/3D, and full provenance.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "max3221.kicad_sym",
    "max3221.kicad_mod",
    "max3221.glb",
    "max3221.step",
    "max3221.lbr",
    "docs/hero.png",
    "docs/max3221-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "max3221-etched.step"
  ],
  "variants": [
    {
      "mpn": "MAX3221CAE (SSOP-16)",
      "kind": "packaging"
    },
    {
      "mpn": "MAX3221IPWR (TSSOP-16)",
      "kind": "packaging"
    },
    {
      "mpn": "MAX3221EAE (+/-15 kV ESD)",
      "kind": "packaging"
    }
  ]
}