[Successful actual measurement] Solution verification board based on CH340C

This project is used to verify the solution verification design of LCSC’s USB chip CH340C ( LCSC No. C84681 )

• CH340 is a USB bus adapter chip that realizes USB to serial port or USB to print port.
• Full-speed USB device interface, compatible with USB V2.0.
• Simulates standard serial ports, used to upgrade original serial port peripherals, or add additional serial ports through USB. Computer side 
• Serial port applications under Windows operating systems are fully compatible and require no modification.
• Hardware full-duplex serial port, built-in transceiver buffer, supports communication baud rate of 50bps~2Mbps.
• Supports commonly used MODEM contact signals RTS, DTR, DCD, RI, DSR, CTS.
• Through external level conversion devices, interfaces such as RS232, RS485, and RS422 are provided.
• The software is compatible with CH341 and you can directly use the CH341 driver.
• Supports 5V power supply voltage and 3.3V power supply voltage and even 3V power supply voltage.
• CH340C has built-in clock and does not require external crystal oscillator
• Available in SOP-16 and SSOP-20 and MSOP-10 lead-free packages, RoHS compliant.

---------copy from datasheet

This solution verification board adds an 8V1.5A self-restoring fuse to the USB input. The main power supply line is 30mil wide and can pass 2A MAX current. This ensures that when a short circuit or overload occurs, the fuse will be blown first. After the problem is eliminated, it can be used directly, which almost avoids the problem of needing to replace the PCB due to burnt lines. This solution verification board defaults to 3V3 Level mode, suitable for 5V/3V3 level microcontroller, no adjustment required. This solution verification board leads to a total of 8 pins CTS/RTS/DTR/RX/TX/GND/5V/3V3

Physical welding diagram: