Overview
The CH340G is a USB-to-serial bridge IC manufactured by WCH (Jiangsu Qinheng Co., Ltd). It has become the de facto standard for cheap serial adapters, replacing the more expensive FTDI chips in budget applications.
Driver Compatibility
Broad Support
CH340 drivers are included in Linux kernel (since 2.6), macOS (since Catalina), and Windows 10/11 automatically installs drivers via Windows Update.
Operating System Support
| OS | Driver Status | Notes |
|---|---|---|
| Windows 11 | Built-in | Auto-installs via WU |
| Windows 10 | Built-in | Auto-installs via WU |
| macOS 14+ | Built-in | Works out of box |
| macOS 10.15-13 | Manual | Download from WCH |
| Linux | Built-in | ch341 module |
| ChromeOS | Built-in | WebSerial API |
Signal Quality Analysis
Testing at various baud rates with 10m cable:
baud_9600:
bit_error_rate: 0
jitter: "<5%"
baud_115200:
bit_error_rate: 0
jitter: "<8%"
baud_921600:
bit_error_rate: 0.001%
jitter: "<12%"
baud_2000000:
bit_error_rate: 0.1%
jitter: "<15%"
note: "Cable length sensitive"Module Variants
Common module configurations:
- Basic (6-pin): TX, RX, GND, 5V, 3.3V, no flow control
- Full (9-pin): Adds DTR, RTS, CTS for auto-reset
- Micro USB: Smaller form factor, same functionality
- Type-C: Modern connector, often includes ESD protection
Comparison with Alternatives
| Feature | CH340G | CP2102 | FT232RL |
|---|---|---|---|
| Price | $0.50 | $1.50 | $4.00 |
| Max Baud | 2Mbps | 1Mbps | 3Mbps |
| Driver | Good | Good | Excellent |
| Reliability | Good | Good | Excellent |
Recommendation
The CH340G offers exceptional value. For development and debugging, it's the obvious choice. Only consider alternatives (FT232RL, CP2102) for production hardware where the small reliability improvement justifies the cost increase.