CH341
Flexible USB bridge supporting parallel port, SPI, and I2C for legacy device upgrades
Product Overview
Description
CH341 is a versatile USB bridge chip designed for upgrading legacy parallel port devices to USB.
With support for parallel port, SPI, and I2C interfaces, this chip provides a migration path for older equipment.
The chip is widely used in programmers, EPROM emulators, and industrial control interfaces.
Product Series
CH
Primary Application
Legacy printer adapters
Key Features
- USB to parallel port conversion
- SPI master interface
- I2C master interface
- EPP and MEM modes
- 8-bit GPIO
- EEPROM configuration
- Built-in oscillator
- WHQL certified drivers
Specifications
| USB | USB 2.0 Full Speed |
|---|---|
| Parallel | EPP/MEM mode |
| SPI | Up to 5MHz |
| I2C | Standard/Fast mode |
| GPIO | 8-bit parallel |
| IO Voltage | 5V/3.3V |
| Package | SOP-28, SSOP-20, DIP-28 |
| Temperature Range | -40°C to +85°C |
Applications
Legacy printer adapters
Electronic system design
EPROM programmers
Electronic system design
Parallel port emulators
Electronic system design
Industrial control
Industrial automation and control
SPI Flash programmers
Electronic system design
I2C device interfaces
Communication and interface
FAE Expert Insights
"CH341 is the go-to solution for upgrading legacy parallel port devices. I've helped dozens of customers migrate old LPT-based equipment to USB using this chip. The EPP mode support is crucial for many industrial applications. While the SPI speed is limited to 5MHz, it's sufficient for configuration Flash and small EEPROMs. The built-in oscillator keeps the BOM simple. For new designs requiring higher SPI speeds, use CH347 instead. But for parallel port replacement, CH341 is unmatched."
Legacy parallel port upgrade solution
— David Liu, BeiLuo