CH340 Datasheet PDF – USB Convert Printer Port Chip

This is a USB-to-serial chip used for communication between a computer and a microcontroller or other embedded device. It is commonly used in electronics projects and is popular due to its low cost and ease of use.

Part Number: CH340

Function: USB Bus Convert Chip

Package: SSOP-20 type

Manufacturer: Jiangsu QinHeng


CH340 datasheet



The CH340 is a USB bus convert chip and it can realize USB convert to serial interface, USB convert to IrDA infrared or USB convert to printer interface.

In serial interface mode, CH340 supplies common MODEM liaison signal, used to enlarge asynchronous serial interface of computer or upgrade the common serial device to USBbus directly.

More detail about USB convert to printer interface please referring to the second manual CH340DS2. In infrared mode, add infrared transceiver to CH340 can compose USB infrared adapter, realize SIR nfrared communication.


1. Full speed USB device interface, conforms to USB Specification Version 2.0, only needs crystal and
capacitance external.

2. Standard USB print interface, used to upgrade the original parallel printer, compatible with the
relative USB criterion.

3. Compatible with Windows operation system, drive program is not need in Windows 2000 and XP,
the application program is totally compatible.





1. USB 2.0 full-speed device interface, compatible with USB 1.1

2. Supports data transfer rates up to 2 Mbps

3. Supports common serial communication protocols such as UART, SPI, and I2C

4. Widely available and supported by many development environments and programming languages

5. Can be used with a variety of microcontrollers and embedded devices


Other data sheets are available within the file: CH340S, CH340R, CH340T

CH340 Datasheet PDF Download

CH340 pdf