UART to HID Keyboard Chip CH9328


CH9328 is a serial UART to HID keyboard chip that is identified as a standard USB HID keyboard device on computers. CH9328 supports one-way data transmission, it can receive the serial UART data (such as ASCII code), and according to the HID keyboard device specification, the data is packaged into a standard keyboard code and uploaded to the computer through the USB port. Through the provided Windows software, the user can also configure the chip’s VID, PID, and various string descriptors. The figure below shows the diagram of its general application.


  • Supports 12Mbps full-speed USB device interface, USB 2.0 compatible, built-in crystal oscillator.
  • Default serial communication baud rate is 9600bps, which supports multiple serial communication formats and common baud rate settings.
  • Supports 5V and 3.3V power supply voltages.
  • Supports configuration of VID, PID, and various USB string descriptors of the chip.
  • Supports configuration of default baud rate of the chip.
  • Complies with USB related specifications and HID device related specifications.
  • Multiple operating modes to apply to different requirements, can simulate full keyboard function.
  • RoHS compliant SOP16 lead-free package.


relation files

file name file content
CH9340DS.PDF CH9340 datasheet, USB CDC to single serial port, built-in crystal oscillator, supports built-in CDC driver in operating system.