CH341A

{
  "schema_version": 1,
  "type": "component",
  "slug": "ch341a",
  "title": "CH341A",
  "brief": "WCH(Jiangsu Qin Heng) USB ICs, SOP-28-300mil. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.",
  "version": "0.1.0",
  "license": "CC-BY-SA-4.0",
  "tags": [
    "component",
    "interface ics",
    "ch341a",
    "factory-2.0.0",
    "extractor-text"
  ],
  "component": {
    "mpn": "CH341A",
    "manufacturer": "WCH(Jiangsu Qin Heng)",
    "package": "SOP-28-300mil",
    "pin_count": 28,
    "category": "Interface ICs",
    "subcategory": "USB ICs",
    "datasheet": "https://datasheet.lcsc.com/datasheet/pdf/1707f009fd730913c0752ada03545060.pdf",
    "parts": {
      "symbol": "ch341a.kicad_sym",
      "footprint": "ch341a.kicad_mod",
      "model_3d": "ch341a-hero.glb",
      "model_3d_plain": "ch341a-etched.glb",
      "model_3d_step": "ch341a-etched.step",
      "model_3d_step_plain": "ch341a.step",
      "lbr": "ch341a.lbr"
    },
    "distributor_links": {
      "lcsc": "C13517"
    },
    "distributor_check": {
      "checked_at": "2026-10-27T01:42:52Z",
      "source": "Component Ocean /api/assign-pns",
      "digikey": {
        "pn": null,
        "status": "no match"
      },
      "mouser": {
        "pn": null,
        "status": "no match"
      }
    },
    "pins": [
      {
        "number": "1",
        "name": "ACT#",
        "type": "output",
        "description": "USB device configuration status output, active low: high while the USB device is unconfigured, low once configured; may drive an LED through a series current-limiting resistor."
      },
      {
        "number": "2",
        "name": "RSTI",
        "type": "input",
        "description": "External reset input, active high with internal pull-down; the chip stays in reset while high and runs about 20 ms of delay after returning low."
      },
      {
        "number": "3",
        "name": "IN7",
        "type": "input",
        "description": "Custom general-purpose input in serial mode; datasheet recommends leaving it unconnected when unused (alternate function AS# in parallel mode)."
      },
      {
        "number": "4",
        "name": "ROV#",
        "type": "tri_state",
        "description": "Serial receive buffer overflow indicator, active low tri-state output; it should stay high in normal operation (alternate functions AFD# and DS# in printer and parallel modes)."
      },
      {
        "number": "5",
        "name": "TXD",
        "type": "output",
        "description": "Serial data output of the asynchronous UART; idles high (alternate functions ERR# in printer and parallel modes)."
      },
      {
        "number": "6",
        "name": "RXD",
        "type": "input",
        "description": "Serial data input of the asynchronous UART with internal pull-up; idles high (alternate function PEMP in printer and parallel modes)."
      },
      {
        "number": "7",
        "name": "INT#",
        "type": "input",
        "description": "Custom interrupt request input, rising-edge active, with internal pull-up."
      },
      {
        "number": "8",
        "name": "IN3",
        "type": "input",
        "description": "Custom general-purpose input in serial mode; datasheet recommends leaving it unconnected when unused (alternate function SLCT in printer and parallel modes)."
      },
      {
        "number": "9",
        "name": "V3",
        "type": "power_in",
        "description": "At 3.3V supply it must be tied to VCC with a 3.0-3.6V input; at 5V supply it needs a 0.01uF to 0.1uF decoupling capacitor."
      },
      {
        "number": "10",
        "name": "UD+",
        "type": "bidirectional",
        "description": "USB D+ data line, connects directly to the USB bus; the chip has the USB pull-up built in."
      },
      {
        "number": "11",
        "name": "UD-",
        "type": "bidirectional",
        "description": "USB D- data line, connects directly to the USB bus."
      },
      {
        "number": "12",
        "name": "GND",
        "type": "power_in",
        "description": "Common ground, connected directly to the USB bus ground."
      },
      {
        "number": "13",
        "name": "XI",
        "type": "input",
        "description": "Crystal oscillator input; CH341A requires an external 12 MHz crystal and load capacitor (or 12 MHz clock input at 11.98-12.02 MHz)."
      },
      {
        "number": "14",
        "name": "XO",
        "type": "output",
        "description": "Inverting crystal oscillator output; requires a 12 MHz crystal and load capacitor to XO and GND."
      },
      {
        "number": "15",
        "name": "CTS#",
        "type": "input",
        "description": "Modem handshake input, clear to send, active low; controlled by the host application, not by the chip."
      },
      {
        "number": "16",
        "name": "DSR#",
        "type": "input",
        "description": "Modem handshake input, data set ready, active low; controlled by the host application."
      },
      {
        "number": "17",
        "name": "RI#",
        "type": "input",
        "description": "Modem handshake input, ring indicator, active low; controlled by the host application."
      },
      {
        "number": "18",
        "name": "DCD#",
        "type": "input",
        "description": "Modem handshake input, carrier detect, active low; controlled by the host application."
      },
      {
        "number": "19",
        "name": "OUT#",
        "type": "tri_state",
        "description": "Custom general-purpose output, active low tri-state; the host application sets its state."
      },
      {
        "number": "20",
        "name": "DTR#",
        "type": "tri_state",
        "description": "Modem handshake output, data terminal ready, active low tri-state; set by the host application."
      },
      {
        "number": "21",
        "name": "RTS#",
        "type": "tri_state",
        "description": "Modem handshake output, request to send, active low tri-state; set by the host application."
      },
      {
        "number": "22",
        "name": "SLP#",
        "type": "tri_state",
        "description": "Sleep state output, active low tri-state (alternate function D7 in parallel and printer modes)."
      },
      {
        "number": "23",
        "name": "SDA",
        "type": "bidirectional",
        "description": "Open-drain configuration data line, with internal pull-up; configures chip function from an external 24Cxx EEPROM or via a direct SCL/SDA strap."
      },
      {
        "number": "24",
        "name": "SCL",
        "type": "output",
        "description": "Open-drain configuration clock output with internal pull-up; connects to the SCL pin of an external serial EEPROM."
      },
      {
        "number": "25",
        "name": "RDY#",
        "type": "output",
        "description": "Serial receive ready output, active low; high means the chip cannot yet receive data (reset, USB not configured, or receive buffer full)."
      },
      {
        "number": "26",
        "name": "TNOW",
        "type": "output",
        "description": "Serial transmit in progress indicator, active high; low again after transmission completes."
      },
      {
        "number": "27",
        "name": "TEN#",
        "type": "input",
        "description": "Serial transmit enable input, active low, with internal pull-up; when high the chip pauses sending, so it must be low or grounded for the chip to transmit."
      },
      {
        "number": "28",
        "name": "VCC",
        "type": "power_in",
        "description": "Positive supply input; 4.0-5.5V with V3 unconnected, or 3.0-3.6V with V3 tied to VCC; requires a 0.1uF decoupling 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: The common-pin table in section 4.2 has multiple columns per row, and the 341B/341A/341F column alig; Pins 3, 4, 5, 6, 7, 8, 15-22, 25 and 27 are multiplexed. Each pin is listed with its asynchronous-se",
          "1/28 pins cited to the wrong page (name found elsewhere): ['14:XO@p3']",
          "1/28 pin names appear NOWHERE in the datasheet text: ['13:XI@p3']"
        ],
        "pages_sent": 12,
        "cost_usd": 0.0382,
        "at": "2026-10-27T01:42:35"
      },
      "datasheet": {
        "url": "https://datasheet.lcsc.com/datasheet/pdf/1707f009fd730913c0752ada03545060.pdf",
        "pages": 12,
        "sha256": "8f76a55cf6fbe6fe",
        "source_tier": "lcsc"
      },
      "cad": "KiCad official (CC-BY-SA 4.0)",
      "pins": {
        "total": 28,
        "described": 28,
        "cites_pages": true,
        "refuses_to_fabricate": true
      }
    },
    "viewers": {
      "symbol": "viewers/symbol.html",
      "footprint": "viewers/footprint.html"
    },
    "models_3d": [
      {
        "file": "ch341a.step",
        "role": "plain",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          11.636,
          18.16,
          2.666
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "ecc34510e8f74b6103a72c2f24133ad80006c738972a56531d1221b277fcecdb",
        "checked": "2026-10-27",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      },
      {
        "file": "ch341a-etched.step",
        "role": "eda",
        "up": "Z",
        "units": "mm",
        "origin": "footprint origin = pad-pattern centre",
        "seat": "z = 0",
        "extents_mm": [
          11.636,
          18.16,
          2.666
        ],
        "zmin_mm": 0,
        "centre_offset_mm": 0,
        "footprint_binding": "identity",
        "sha256": "006934fbcfa5f4e26c321f3def6f14d14acdab5ff59e38d5e500ac2cf3276282",
        "checked": "2026-10-27",
        "checked_by": "factory/step_pose.py (Z-up, origin, seat, binding)"
      }
    ]
  },
  "metadata": {
    "specs": {
      "Manufacturer": "WCH(Jiangsu Qin Heng)",
      "Package": "SOP-28-300mil",
      "Category": "Interface ICs",
      "Pins": "28"
    }
  },
  "variants": [],
  "sections": [
    "hero",
    "viewers",
    "readme",
    "breadcrumbs",
    "info"
  ],
  "discovery_triggers": [
    "ch341a"
  ],
  "discovery_pitch": "CH341A (WCH(Jiangsu Qin Heng)) component page: datasheet pinout, KiCad symbol, footprint and 3D.",
  "author": {
    "name": "Ray",
    "email": "[email protected]"
  },
  "dependencies": {},
  "hero": {
    "type": "image",
    "path": "docs/hero.png"
  },
  "files": [
    "page.json",
    "README.md",
    "ch341a.kicad_sym",
    "ch341a.kicad_mod",
    "ch341a.glb",
    "ch341a.step",
    "ch341a.lbr",
    "docs/hero.png",
    "docs/ch341a-datasheet.pdf",
    "viewers/symbol.html",
    "viewers/footprint.html",
    "ch341a-hero.glb",
    "ch341a-hero.overlay.json",
    "ch341a-etched.glb"
  ],
  "visibility": {
    "public": true
  }
}