CH341A Datasheet – USB Bus Convert Chip (SOP 28)

This is one of the Convert Chip types.

Part Number : CH341A

Function  : USB Bus Convert Chip

Package : SOP 28 Pin

Manufactures : Jiangsu QinHeng ( )


CH341A USB Bus Convert Chip


CH341 is a USBbus convert chip, providing UART, printerport, parallel and synchronous serial with 2-wire or4-wire through USBbus. In UART mode, CH341 provides alternant rate control signals such as serial transfer enable, serial receive in ready etc. It also supplies common MODEM communication signal in order to expand UART for computer orupgrade common synchronous interface device to USB bus directly.

In printer port mode, CH341 supplies standard USB printerport which compounds USB relevant protocol and Windows operate system used toupgrade ordinary parallel printer to USB bus directly. In parallel mode, CH341 gives out8-bit parallel in EPP or MEM mode. It canbe used to input/output data directly without MCU/DSP.

CH341A Pinout

CH341A datasheet pdf


1. Full speed USB device interface, conforms to USB Specification Version2.0, only needs crystal and capacitance external.

2. Optional:define Vender ID, production ID and listnumber through external low-cost serial EEPROM.

3. Supports5V and3.3Vpower source.

4. Low-cost, directly convert serial peripheral equipment, parallel printer and parallel peripheral

CH341A Datasheet


CH340 Datasheet – USB Convert Printer Port Chip

Part Number : CH340

Function : USB Bus Convert Chip

Package : SSOP-20 type

Manufacturers : Jiangsu QinHeng

Image :

CH340 datasheet


Description :

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.

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

CH340 Datasheet PDF Download

CH340 pdf