The DataSheet of CH341 (the first)

1

USB bus convert chip CH341

English DataSheet

Version:2D

http://wch.cn

http://wch-ic.com

1. Introduction

CH341 is a USB bus convert chip, providing UART, printer port, parallel and synchronous serial with

2-wire or 4-wire through USB bus.

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 or upgrade common synchronous interface device to USB bus directly.

In printer port mode, CH341 supplies standard USB printer port which compounds USB relevant

protocol and Windows operate system used to upgrade ordinary parallel printer to USB bus directly.

In parallel mode, CH341 gives out 8-bit parallel in EPP or MEM mode. It can be used to input/output

data directly without MCU/DSP.

Besides, CH341A also supports some common synchronous serial such as 2-wire (SCL, SDA) and

4-wire (CS, SCK/CLK, MISO/SDI/DIN and MOSI/SDO/DOUT) interface.

D+

D-

2. Features

2.1.Introduction

● Full speed USB device interface, conforms to USB Specification Version 2.0, only needs crystal and

capacitance external.

● Optional: define Vender ID, production ID and list number through external low-cost serial EEPROM.

● Supports 5V and 3.3V power source.

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

equipment.

● SOP-28 and SSOP-20 package lead free, compatible with RoHS.

● Only compatible with application layer because interfaces are diverted via USB.

Computer

and other

USB host

CH341

Convert chip

UART/RS232/RS485/RS422

Parallel printer to USB printer

EPP parallel and MEM parallel

Common 2-wire and 4-wire synchronous serial