WCH CH342K

CH342 is a USB bus conversion chip that implements USB to dual asynchronous serial ports. Each serial port supports high-speed full-duplex operation and parity checking, and provides commonly used MODEM handshake signals. It is designed to expand asynchronous serial ports for computers, or to directly upgrade ordinary serial port devices or MCUs to USB bus connectivity.

• Full-speed USB device interface, compatible with USB V2.0
• Built-in firmware emulating standard serial port, for upgrading legacy serial peripherals or adding extra serial ports via USB
• Fully compatible with serial port applications under Windows OS on the host side, no modification required
• Serial port supports 5, 6, 7, or 8 data bits; supports odd, even, space, mark, and no parity
• Supports commonly used MODEM handshaking signals: RTS, DTR, DCD, RI, DSR, CTS
• Supports CTS and RTS hardware automatic flow control
• Supports half-duplex with transmit status output for RS485 switching
• Supports RS232 interface via external level-shifting components
• USB side supports 5V and 3.3V supply voltage
• Serial port I/O with independent power supply, supporting 5V, 3.3V, 2.5V, 1.8V supply voltages
• Built-in power-on reset and built-in clock, no external crystal required
• CH342F features built-in EEPROM for configuring VID, PID, maximum current, manufacturer and product information strings, and other parameters
• Built-in Unique ID (USB Serial Number)
• Available in QFN24 and ESSOP10 lead-free packages, RoHS compliant

• USB to dual 9-wire TTL serial port
• USB to dual 9-wire RS232 serial port
• USB to dual RS485
• Connects to dual MCU serial ports with independent power supply