CH340G USB to Serial UART Bridge Controller
USB serial converter, UART, SOIC-16
Aliase:CH340, USB Serial Adapter, Arduino Nano USB IC
SOIC-16 Top View
16 Pins
Pinout Table16
| Pin | Signal / Name | Type | Alternative Functions |
|---|---|---|---|
| 1 | GND | Ground | System Ground (0V) |
| 2 | TXD | Digital | UART Transmit Data Output (from USB host to target device) |
| 3 | RXD | Digital | UART Receive Data Input (from target device to USB host) |
| 4 | V3 | Power | Internal 3.3V Regulator Output — connect 100nF bypass cap to GND; do not drive external loads3.3V I/O Supply Input — when operating at 3.3V, connect V3 to VCC and omit the bypass cap |
| 5 | UD+ | Digital | USB Data Positive (D+) — connect directly to USB connector D+ |
| 6 | UD- | Digital | USB Data Negative (D-) — connect directly to USB connector D- |
| 7 | XI | Digital | Crystal Oscillator Input — connect 12MHz crystal; load capacitors (22pF typical) to GND |
| 8 | XO | Digital | Crystal Oscillator Output — connect to crystal only; do not load |
| 9 | CTS | Digital | CTS — Clear to Send Hardware Flow Control Input (Active Low) |
| 10 | DSR | Digital | DSR — Data Set Ready Input (Active Low, RS-232 modem status signal) |
| 11 | RI | Digital | RI — Ring Indicator Input (Active Low, RS-232 modem status signal) |
| 12 | DCD | Digital | DCD — Data Carrier Detect Input (Active Low, RS-232 modem status signal) |
| 13 | DTR | Digital | DTR — Data Terminal Ready Output (Active Low; commonly used to reset Arduino bootloader) |
| 14 | RTS | Digital | RTS — Request to Send Hardware Flow Control Output (Active Low) |
| 15 | R232 | Digital | RS-232 Level Enable — pull HIGH via 100kΩ to enable auxiliary RS-232 charge-pump circuit for ±12V output swing; leave LOW or float for TTL-level operation |
| 16 | VCC | Power | Positive Power Supply (3.3V or 5V; add 100nF bypass cap to GND) |