CH344L

{
  "slug": "ch344l",
  "version": "0.1.0",
  "type": "component",
  "description": "WCH Jiangsu Qin Heng USB Converters, LQFP-48(7x7). Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "tags": [
    "component",
    "interface",
    "ch344l",
    "factory-2.0.0",
    "extractor-text"
  ],
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "ch344l.kicad_sym",
    "ch344l.kicad_mod",
    "ch344l.glb",
    "ch344l.step",
    "ch344l.lbr",
    "docs/hero.png",
    "docs/ch344l-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "ch344l-hero.glb",
    "ch344l-hero.overlay.json",
    "ch344l-etched.glb"
  ],
  "component": {
    "mpn": "CH344L",
    "manufacturer": "WCH Jiangsu Qin Heng",
    "package": "LQFP-48(7x7)",
    "pin_count": 48,
    "category": "Interface",
    "subcategory": "USB Converters",
    "datasheet": "https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8618866860662546432",
    "parts": {
      "symbol": "ch344l.kicad_sym",
      "footprint": "ch344l.kicad_mod",
      "model_3d": "ch344l-hero.glb",
      "model_3d_plain": "ch344l-etched.glb",
      "model_3d_step": "ch344l-etched.step",
      "model_3d_step_plain": "ch344l.step",
      "lbr": "ch344l.lbr"
    },
    "distributor_links": {
      "lcsc": "C2887250"
    },
    "distributor_check": {
      "checked_at": "2026-10-19T00:43:34Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": null,
        "status": "no match"
      },
      "mouser": {
        "pn": null,
        "status": "no match"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "2",
        "name": "CFG2",
        "type": "input",
        "description": "CH344L TNOW/DTR function select: high or floating at power-up makes all DTRx/TNOWx pins TNOW, low makes them DTR, and individual ports can be set to TNOW with a 4.7kΩ pull-down on their DTRx/TNOWx pin."
      },
      {
        "number": "3",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "4",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "5",
        "name": "XI",
        "type": "input",
        "description": "Crystal oscillator input; an 8MHz crystal with ~22pF load capacitors to GND is recommended, and CH344L may use its internal clock if the crystal is omitted at the cost of larger baud-rate error."
      },
      {
        "number": "6",
        "name": "XO",
        "type": "output",
        "description": "Crystal oscillator inverting output; connects to the other side of the 8MHz crystal with its ~22pF load capacitor to GND."
      },
      {
        "number": "7",
        "name": "RESET",
        "type": "input",
        "description": "External reset input, active low, with internal pull-up (RPU typ. 40kΩ, range 30-60kΩ)."
      },
      {
        "number": "8",
        "name": "GND",
        "type": "power_in",
        "description": "Common ground; must be connected to the USB bus ground."
      },
      {
        "number": "9",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply input at 3.0-3.6V (3.3V typical), decoupled to GND with a ~0.1µF capacitor."
      },
      {
        "number": "10",
        "name": "CTS1/GPIO2",
        "type": "input",
        "description": "UART1 modem input CTS, active low, also usable as general-purpose GPIO2 and for hardware flow control."
      },
      {
        "number": "11",
        "name": "RTS1/GPIO3",
        "type": "output",
        "description": "UART1 modem output RTS, active low, also general-purpose GPIO3."
      },
      {
        "number": "12",
        "name": "TXD1",
        "type": "output",
        "description": "UART1 serial data output, idle high."
      },
      {
        "number": "13",
        "name": "RXD1",
        "type": "input",
        "description": "UART1 serial data input with internal pull-up."
      },
      {
        "number": "14",
        "name": "ACT",
        "type": "output",
        "description": "USB configuration complete status output, active low."
      },
      {
        "number": "15",
        "name": "TX_S",
        "type": "output",
        "description": "Serial data transmit status output; outputs a 200ms-period pulse while any UART is transmitting."
      },
      {
        "number": "16",
        "name": "RX_S",
        "type": "output",
        "description": "Serial data receive status output; outputs a 200ms-period pulse while any UART is receiving."
      },
      {
        "number": "17",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "18",
        "name": "DTR1/TNOW1/GPIO9",
        "type": "bidirectional",
        "description": "UART1 modem output DTR (active low) or RS485 TNOW1 transmit/receive control, selected at power-up by CFG2; also general-purpose GPIO9."
      },
      {
        "number": "19",
        "name": "DTR2/TNOW2/GPIO10",
        "type": "bidirectional",
        "description": "UART2 modem output DTR (active low) or RS485 TNOW2 transmit/receive control, selected at power-up by CFG2; also general-purpose GPIO10."
      },
      {
        "number": "20",
        "name": "GND",
        "type": "power_in",
        "description": "Common ground; must be connected to the USB bus ground."
      },
      {
        "number": "21",
        "name": "TXD2",
        "type": "output",
        "description": "UART2 serial data output, idle high."
      },
      {
        "number": "22",
        "name": "RXD2",
        "type": "input",
        "description": "UART2 serial data input with internal pull-up."
      },
      {
        "number": "23",
        "name": "GND",
        "type": "power_in",
        "description": "Common ground; must be connected to the USB bus ground."
      },
      {
        "number": "24",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply input at 3.0-3.6V (3.3V typical), decoupled to GND with a ~0.1µF capacitor."
      },
      {
        "number": "25",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "26",
        "name": "CTS2/GPIO4",
        "type": "input",
        "description": "UART2 modem input CTS, active low, also general-purpose GPIO4."
      },
      {
        "number": "27",
        "name": "RTS2/GPIO5",
        "type": "output",
        "description": "UART2 modem output RTS, active low, also general-purpose GPIO5."
      },
      {
        "number": "28",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "29",
        "name": "TXD3",
        "type": "output",
        "description": "UART3 serial data output, idle high."
      },
      {
        "number": "30",
        "name": "TXD0",
        "type": "output",
        "description": "UART0 serial data output, idle high."
      },
      {
        "number": "31",
        "name": "RXD0",
        "type": "input",
        "description": "UART0 serial data input with internal pull-up."
      },
      {
        "number": "32",
        "name": "UD-",
        "type": "bidirectional",
        "description": "USB D- data line, connected directly to the USB bus D- with no series resistor allowed."
      },
      {
        "number": "33",
        "name": "UD+",
        "type": "bidirectional",
        "description": "USB D+ data line, connected directly to the USB bus D+ with no series resistor allowed."
      },
      {
        "number": "34",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "35",
        "name": "GND",
        "type": "power_in",
        "description": "Common ground; must be connected to the USB bus ground."
      },
      {
        "number": "36",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply input at 3.0-3.6V (3.3V typical), decoupled to GND with a ~0.1µF capacitor."
      },
      {
        "number": "37",
        "name": "NC",
        "type": "unconnected",
        "description": "No connect; must be left floating on CH344L."
      },
      {
        "number": "38",
        "name": "CFG",
        "type": "input",
        "description": "Hardware flow control enable, active low, with internal pull-up."
      },
      {
        "number": "39",
        "name": "DTR0/TNOW0/GPIO8",
        "type": "bidirectional",
        "description": "UART0 modem output DTR (active low) or RS485 TNOW0 transmit/receive control, selected at power-up by CFG2; also general-purpose GPIO8."
      },
      {
        "number": "40",
        "name": "RTS0/GPIO1",
        "type": "output",
        "description": "UART0 modem output RTS, active low, also general-purpose GPIO1; if pulled low at power-up, internal EEPROM configuration is disabled and chip default parameters are used."
      },
      {
        "number": "41",
        "name": "CTS0/GPIO0",
        "type": "input",
        "description": "UART0 modem input CTS, active low, also general-purpose GPIO0."
      },
      {
        "number": "42",
        "name": "RXD3",
        "type": "input",
        "description": "UART3 serial data input; requires an external pull-up resistor on CH344L."
      },
      {
        "number": "43",
        "name": "DTR3/TNOW3/GPIO11",
        "type": "bidirectional",
        "description": "UART3 modem output DTR (active low) or RS485 TNOW3 transmit/receive control, selected at power-up by CFG2; also general-purpose GPIO11."
      },
      {
        "number": "44",
        "name": "TEST",
        "type": "input",
        "description": "Internal test pin; connect to GND through a pull-down (typ. 4.7kΩ) or tie directly to GND."
      },
      {
        "number": "45",
        "name": "RTS3/GPIO7",
        "type": "output",
        "description": "UART3 modem output RTS, active low, also general-purpose GPIO7."
      },
      {
        "number": "46",
        "name": "CTS3/GPIO6",
        "type": "input",
        "description": "UART3 modem input CTS, active low, also general-purpose GPIO6."
      },
      {
        "number": "47",
        "name": "GND",
        "type": "power_in",
        "description": "Common ground; must be connected to the USB bus ground."
      },
      {
        "number": "48",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply input at 3.0-3.6V (3.3V typical), decoupled to GND with a ~0.1µF capacitor."
      }
    ],
    "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: Pinout taken from the CH344L column of the pin table (pages 3-5) and cross-checked against the CH344; Pin 14 is labeled ACT/CFG/DCD3 in the shared table, but the CH344L diagram and CH344L text name it A; The table marks several CH344L inputs as 输入(FT), but the datasheet note says FT (5V-tolerant input) ",
          "1/48 pins cited to the wrong page (name found elsewhere): ['5:XI@p3']",
          "1/48 pin names appear NOWHERE in the datasheet text: ['6:XO@p3']"
        ],
        "pages_sent": 8,
        "cost_usd": 0.1039,
        "at": "2026-10-19T00:41:06"
      },
      "datasheet": {
        "url": "https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8618866860662546432",
        "pages": 8,
        "sha256": "9044ddf347f308c1",
        "source_tier": "lcsc"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 48,
        "described": 48,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "ch344l.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          9.0,
          9.0,
          1.5
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "9dea352d93177c2904afd7d7b68ea8855ce1ab691f69f8b3e13655600514b6bf",
        "checked": "2026-10-19",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "ch344l-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          9.0,
          9.0,
          1.5
        ],
        "zmin_mm": -0.0,
        "centre_offset_mm": 0.0,
        "footprint_binding": "identity",
        "sha256": "33013f1cedb2c90b25b863a50133ccbd5c2668eadee1519445ceed4481b851e7",
        "checked": "2026-10-19",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  }
}