CH318T

{
  "slug": "ch318t",
  "version": "0.1.0",
  "type": "component",
  "description": "WCH(南京沁恒) Isolated USB ICs, TSSOP-20. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "signal isolation devices",
    "ch318t",
    "factory-2.0.0",
    "extractor-text"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "ch318t.kicad_sym",
    "ch318t.kicad_mod",
    "ch318t.glb",
    "ch318t.step",
    "ch318t.lbr",
    "docs/hero.png",
    "docs/ch318t-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "ch318t-hero.glb",
    "ch318t-hero.overlay.json",
    "ch318t-etched.glb"
  ],
  "component": {
    "mpn": "CH318T",
    "manufacturer": "WCH(南京沁恒)",
    "package": "TSSOP-20",
    "pin_count": 20,
    "category": "Signal Isolation Devices",
    "subcategory": "Isolated USB ICs",
    "datasheet": "https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8618867168255483904",
    "parts": {
      "symbol": "ch318t.kicad_sym",
      "footprint": "ch318t.kicad_mod",
      "model_3d": "ch318t-hero.glb",
      "model_3d_plain": "ch318t-etched.glb",
      "model_3d_step": "ch318t-etched.step",
      "model_3d_step_plain": "ch318t.step",
      "lbr": "ch318t.lbr"
    },
    "distributor_links": {
      "lcsc": "C42387966"
    },
    "distributor_check": {
      "checked_at": "2026-10-18T05:02:58Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": null,
        "status": "no match"
      },
      "mouser": {
        "pn": null,
        "status": "no match"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "DMX",
        "type": "passive",
        "description": "Analog differential-pair signal, connected through the isolation capacitor or network transformer directly to the negative end of the differential extension line."
      },
      {
        "number": "2",
        "name": "DPX",
        "type": "passive",
        "description": "Analog differential-pair signal, connected through the isolation capacitor or network transformer directly to the positive end of the differential extension line."
      },
      {
        "number": "3",
        "name": "XO",
        "type": "output",
        "description": "Crystal oscillator inverting output; connects to the other terminal of the external crystal."
      },
      {
        "number": "4",
        "name": "XI",
        "type": "input",
        "description": "Crystal oscillator input; connects to one terminal of the external crystal (an external clock input is also supported per the features list)."
      },
      {
        "number": "5",
        "name": "AVDDK",
        "type": "power_in",
        "description": "Analog core power pin; requires a 1uF decoupling capacitor to ground."
      },
      {
        "number": "6",
        "name": "DMU",
        "type": "bidirectional",
        "description": "USB D- signal: upstream port D- in host (upstream) mode, or downstream port 1 D- in device (downstream) mode."
      },
      {
        "number": "7",
        "name": "DPU",
        "type": "bidirectional",
        "description": "USB D+ signal: upstream port D+ in host (upstream) mode, or downstream port 1 D+ in device (downstream) mode."
      },
      {
        "number": "8",
        "name": "DM2",
        "type": "bidirectional",
        "description": "USB D- signal of downstream port 2 (device-mode chip only, per the function description)."
      },
      {
        "number": "9",
        "name": "DP2",
        "type": "bidirectional",
        "description": "USB D+ signal of downstream port 2 (device-mode chip only, per the function description)."
      },
      {
        "number": "10",
        "name": "IO1",
        "type": "bidirectional",
        "description": "Downstream general-purpose I/O sideband signal with tens-of-milliseconds mapping delay; input in host mode, output in device mode, mirroring the host-side IO1 level to the device side when high or low."
      },
      {
        "number": "11",
        "name": "IO2",
        "type": "bidirectional",
        "description": "Upstream general-purpose I/O sideband signal with tens-of-milliseconds mapping delay; output in host mode and input in device mode, with the device-side level mirrored to the host side."
      },
      {
        "number": "12",
        "name": "IO3",
        "type": "bidirectional",
        "description": "Upstream general-purpose I/O sideband signal with tens-of-milliseconds mapping delay; output in host mode and input in device mode, with the device-side level mirrored to the host side."
      },
      {
        "number": "13",
        "name": "LED/MODE",
        "type": "bidirectional",
        "description": "Dual function: LED output for host/device chip connection status (active low, internal pull-up); during reset it selects mode, floating or pulled up through 5.1K to VDD33 for host mode, pulled down through 5.1K to GND for device mode. Rated 3.3V signal input with 5V tolerance."
      },
      {
        "number": "14",
        "name": "DVDDK",
        "type": "power_in",
        "description": "Digital core power pin; requires a 0.1uF decoupling capacitor to ground."
      },
      {
        "number": "15",
        "name": "GND",
        "type": "power_in",
        "description": "Common ground pin."
      },
      {
        "number": "16",
        "name": "VDD33",
        "type": "power_in",
        "description": "Analog supply input, externally supplied at 3.3V; requires a 1uF decoupling capacitor."
      },
      {
        "number": "17",
        "name": "NC",
        "type": "unconnected",
        "description": "Reserved pin; must not be connected."
      },
      {
        "number": "18",
        "name": "NC",
        "type": "unconnected",
        "description": "Reserved pin; must not be connected."
      },
      {
        "number": "19",
        "name": "NC",
        "type": "unconnected",
        "description": "Reserved pin; must not be connected."
      },
      {
        "number": "20",
        "name": "NC",
        "type": "unconnected",
        "description": "Reserved pin; must not be connected."
      }
    ],
    "provenance": {
      "extractor": "extract_pins 0.3",
      "factory_chain": {
        "factory": "2.0.0",
        "extractor": "extract_pins 0.3",
        "primary_model": "claude-haiku-5-5",
        "primary_mode": "text",
        "consensus_model": "claude-sonnet-5-5",
        "consensus": "agreed",
        "guards": "pin_guards 0.1: passed",
        "guard_notes": [
          "extractor flagged: Datasheet classifies DMX/DPX only as 'analog signal'; mapped to KiCad passive as a judgment call, no; Table lists AVDDK and DVDDK only as 'P' (power or ground) with decoupling values; mapped to power_in; Pin direction depends on mode (host vs. device) and on the reset-time mode configuration of LED/MODE",
          "2/20 pins cited to the wrong page (name found elsewhere): ['3:XO@p2', '4:XI@p2']"
        ],
        "pages_sent": 9,
        "cost_usd": 0.0519,
        "at": "2026-10-18T04:59:30"
      },
      "datasheet": {
        "url": "https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8618867168255483904",
        "pages": 9,
        "sha256": "b2afb37bcc476658",
        "source_tier": "lcsc"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 20,
        "described": 20,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "ch318t.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.4,
          6.5,
          1.2
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "97339947f3a7196470ec2f1d9f9b92bb2fc2ab66ad53be0cf105192585ef3c9a",
        "checked": "2026-10-18",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "ch318t-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          6.4,
          6.5,
          1.2
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "4783d83e9abae007e8357286b3f5dbb649603667d3d237154a91c6d8c7887a93",
        "checked": "2026-10-18",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  }
}