Loading…
SOP-16 · CH340G
ActiveUSB-to-UART Bridges
CH340G
WCH (Jiangsu Qin Heng) · SOP-16 · USB-to-UART Bridges
Price on Request
Get a competitive quote within 24 hours. Volume discounts available. Shenzhen stock ships in 1-2 business days.
Overview
The CH340G is a low-cost USB-to-UART bridge from WCH (Jiangsu Qin Heng Electronics), the company behind most of the USB-serial circuitry on Arduino-compatible boards manufactured in China. It converts a standard USB 2.0 full-speed connection to an asynchronous serial port with support for baud rates from 50 bps to 2 Mbps, complete with hardware flow-control signals (RTS, DTR, CTS, DSR, RI, DCD) and modem-control emulation.
The chip integrates the required clock circuitry (the CH340G variant uses an external 12 MHz crystal, the CH340C variant integrates the oscillator on-die), reducing external component count to just three capacitors and a USB connector. On Windows, macOS and Linux it enumerates as a virtual COM port using WCH's freely distributed driver, or on modern Windows 10/11 as a CDC-ACM device with no driver installation needed at all.
Two variants dominate: CH340G (SOP-16, needs external 12 MHz crystal) and CH340C (SOP-16, integrated oscillator, simpler BOM). There are also CH340B (adds EEPROM for VID/PID customization), CH340E (compact MSOP-10 for space-constrained designs), and CH340N (SOP-8, integrated oscillator).
Compared with FTDI's FT232RL (~$3), the CH340G (~$0.50) is roughly 6× cheaper, which is why it became the default on Arduino Nano clones, ESP8266 development boards (NodeMCU, Wemos D1 Mini) and dozens of STM32 "Blue Pill" USB adapters. The tradeoff is that Windows drivers on very old systems may need manual installation, and some Linux kernels before 4.0 have quirky behavior at non-standard baud rates.
Our Shenzhen stock of CH340G comes directly from WCH via authorized channel. MOQ 1 reel (1,500 pcs SOP-16) or 100 pcs loose for prototyping.
Key Features
- USB 2.0 full-speed to UART bridge with 50 bps - 2 Mbps baud
- Integrated oscillator (CH340C) or external 12 MHz crystal (CH340G)
- Full modem control signals: RTS, DTR, CTS, DSR, RI, DCD
- Virtual COM port drivers for Windows / macOS / Linux
Typical Applications
- Arduino Nano and Uno clone USB interfaces
- ESP8266 / ESP32 development boards (NodeMCU, Wemos, HiLetgo)
- USB-to-serial debug cables for routers, set-top boxes, IoT devices
- Programming adapters for STM32 / AVR / PIC bootloaders
- Industrial PC-to-PLC communication over RS-232 (with MAX3232)
Specifications
- Interface
- USB to UART
- Max Baud Rate
- 2 Mbps
- Supply Voltage
- 3.3 or 5 V
- USB Version
- USB 2.0 Full-Speed
- Operating Temperature
- -40 to 85 °C
- Mounting Type
- Surface Mount
- Pins
- 16
- RoHS
- Compliant
Procurement Tips
For new designs, prefer CH340C over CH340G — the integrated oscillator eliminates the external crystal, saving board space and $0.03 of BOM cost.
Frequently Asked Questions
What is the difference between CH340G, CH340C, CH340B, CH340E and CH340N?
All are USB-UART bridges with the same protocol. CH340G is the classic SOP-16 with external crystal. CH340C integrates the crystal (SOP-16, drop-in replacement for G with the crystal removed). CH340B adds EEPROM for custom VID/PID. CH340E is MSOP-10 for compact boards. CH340N is SOP-8 with integrated oscillator. Choose based on package and whether you need custom VID/PID.
Why does my CH340G board show "Unknown Device" on Windows 10?
Windows 10 1803+ ships with a generic CH340 driver, but very cheap clones with fake WCH IDs sometimes fail. Download the official driver from WCH (wch.cn/downloads) and install manually. On macOS 10.13+ use the signed CH34xVCPDriver. Linux has native ch341 kernel module since 3.x.
Is CH340 better or worse than FTDI FT232RL?
FTDI is more robust (industrial-grade drivers, better ESD tolerance, native CDC-ACM without driver install on any modern OS) and has configurable EEPROM. CH340 is 6× cheaper and adequate for consumer and hobbyist products. For industrial or medical designs, spec FTDI. For mass-market IoT and Arduino-compatible, CH340 wins on cost.
Can I use CH340G for high-baud applications like 3 Mbps?
No. Max is 2 Mbps, and stable operation is typically up to 921,600 bps. For higher speeds use CP2102N (Silicon Labs, up to 3 Mbps) or FT232H (up to 12 Mbps MPSSE).
How do I detect counterfeit CH340G?
Genuine WCH parts have laser-etched "WCH" logo plus "CH340G" and a date code, matte tin leads, and consistent weight. Fakes often use remarked dies that only work at low baud rates or fail after months. Test at 921,600 bps on a real board — clones typically drop bytes.
MOQ and lead time?
MOQ 1,500 pcs on reel for CH340G, or 100 pcs loose. WCH authorized channel ships in 3-5 days; Shenzhen stock available same-day.
Alternatives & Equivalents
View full cross-reference table →Need CH340G pricing and availability?
Submit an RFQ — we reply within 24 hours with stock, pricing, lead time and packaging options.
Request a Quote →