CH340G USB to Serial Converter IC SOP-16

CH340G USB to Serial Converter IC SOP-16 is a highly cost-effective and essential chip that efficiently implements the conversion from a USB interface to a standard serial UART interface. This component provides a straightforward solution, allowing developers to easily connect their microcontrollers, FPGAs, or other devices with a serial port to a PC via the universal serial bus. The CH340G fully supports the USB 1.1 and USB 2.0 specifications; consequently, it offers broad compatibility across various operating systems, including Windows, Linux, and macOS. Furthermore, its integrated oscillator circuitry eliminates the need for an external crystal, which dramatically reduces the overall component count and saves valuable PCB space. Therefore, designers frequently select this compact SOP-16 chip for mass-production and cost-sensitive embedded projects.

Key Features:

• Integrated Clock Circuit: The CH340G incorporates an internal clock oscillator; thus, it eliminates the need for an external crystal or ceramic resonator, simplifying the circuit design.
• Full-Speed USB Interface: It provides a standard USB 2.0 interface with full-speed operation, supporting 12Mbps data transfer rates.
• Comprehensive Serial Support: The chip fully supports common handshake signals (RTS, DTR, DCD, RI, DSR, CTS), allowing it to emulate a standard serial port on the PC end.
• Wide Baud Rate Range: The serial port supports data rates from 50 bps up to 2 Mbps, accommodating various communication requirements.
• Low Operating Voltage: The CH340G operates efficiently on a 5V supply and its I/O pins are typically 3.3V tolerant or selectable, facilitating seamless integration with modern microcontrollers.

Technical Specifications:

• Interface Protocol: USB 1.1 / USB 2.0 Full-Speed
• Maximum Data Rate: 2 Mbps (Serial UART)
• Baud Rate Range: 50 bps ≤ Rate ≤ 2,000,000 bps
• Working Voltage (V_CC): 5 V (USB supply)
• Supported OS: Windows, Linux, macOS, Android (with appropriate drivers)
• Operating Temperature Range: −40°C to +85°C

Mechanical Specifications:

• Package Type: SOP-16 (Small Outline Package)
• Mounting: Surface Mount Technology (SMT)
• Pin Count: 16 pins
• Humidity Resistance: Meets standard industrial moisture sensitivity levels (MSL).

Dimensions:

• Body Length: ≈ 10.3 mm
• Body Width: ≈ 3.9 mm
• Pin Pitch: 1.27 mm (Standard SOP pitch)
• Lead Material: Tinned Copper
• Weight: < 0.5 g (Extremely lightweight for compact PCBs)

Pinout and Wiring:

• V3: Connect a 0.1 μF capacitor between this pin and GND. This pin generates the internal 3.3V power supply for the chip’s core logic.
• TXD: Serial data transmit output pin; connect this pin to the RXD pin of the target microcontroller.
• RXD: Serial data receive input pin; connect this pin to the TXD pin of the target microcontroller.
• D+ / D−: These pins connect directly to the D+ and D− data lines of the USB port, establishing the communication path.
• RTS, DTR, etc.: These are handshake signal pins, which you can use for automatic programming or flow control, although they are often left unconnected for basic data transfer.

Datasheet Reference:

• Download WCH CH340G Datasheet (English/Chinese)

Commonly Used in:

• Development Boards: Integrated onto popular Arduino clone boards (e.g., Uno, Nano) to provide USB connectivity for programming and debugging.
• Serial Debugging Adapters: Forming the core component of many low-cost USB-to-TTL serial modules.
• IoT Devices: Embedded within custom IoT hardware for initial configuration and firmware updates.

Applications:

• Microcontroller Programming: Uploading code and sketches to devices like AVR and ESP microcontrollers via the bootloader.
• Data Logging: Facilitating the transfer of sensor and telemetry data from an embedded system to a host PC for analysis.
• Firmware Updates: Providing a reliable serial link for updating the firmware of routers, network devices, and custom electronics.

Equivalent Models:

• FTDI FT232R: However, this is the industry-standard USB-to-UART chip, offering similar functionality but typically at a higher cost and often requiring an external crystal.
• CP2102 (Silicon Labs): A functionally comparable, highly integrated USB-to-UART bridge IC, which also eliminates the need for an external crystal.
• PL2303 (Prolific): Another popular, low-cost alternative for USB to serial conversion, used widely in various adapter cables.

Package Includes:

• 1 x CH340G USB to Serial Converter IC SOP-16