WCH CH9434M

CH9434 is an SPI-to-quad-UART bridge chip that provides four full-duplex 9-wire asynchronous serial ports for expanding the asynchronous serial interfaces of MCUs or embedded systems. The chip integrates four 16C550-compatible asynchronous UARTs, supporting baud rates up to 4Mbps. It offers up to 25 GPIO pins and includes a TNOW pin for automatic TX/RX switching in half-duplex communication.

• Operating voltage: 3.3V
• Programmable baud rate settings from 1200 bps to 4000000 bps
• Independent FIFO buffers per UART direction: 1536-byte TX buffer and 2048-byte RX buffer
• Four fully independent async UARTs, 16C550-compatible with enhanced features
• Supports 5, 6, 7, 8 data bits and 1 or 2 stop bits
• Supports odd, even, none, space (0), and mark (1) parity modes
• Supports common modem control signals: RTS, DTR, DCD, RI, DSR, and CTS
• TX/RX enable control pins for half-duplex RS485 communication
• SPI interface up to 32 Mbit/s
• Low-power sleep mode with SPI wake-up support
• Programmable GPIO
• Requires external 32 MHz crystal as clock source
• QFN48 lead-free package, RoHS compliant

• Microcontroller/DSP/Embedded Systems
• Industrial Automation RS-485 Communication
• Serial Device Servers & Multi-port Serial Cards
• Wireless Data Transmission with Bluetooth, 4G, Wi-Fi Serial Modules