Dual UART chip CH432


The CH432 is a dual UART chip that includes two 16C550-compatible asynchronous serial ports, supports half-duplex transceiver automatic switching and IrDA infrared codec, and supports communication baud rates up to 4Mbps, it can be used for RS232 serial port expansion of MCU/embedded system, high-speed serial port with automatic hardware rate control, RS485 communication, IrDA communication, etc. The figure below is a block diagram of its general application.


  • Two asynchronous serial ports that are completely independent, compatible with 16C450, 16C550 and 16C552 and enhanced.
  • Supports 5, 6, 7 or 8 data bits and 1 or 2 stop bits.
  • Supports odd verification, even verification, no verification, blank 0, flag 1 and other verification methods.
  • Programmable communication baud rate, support 115200bps and communication baud rate up to 4Mbps.
  • Built-in 16-byte FIFO fist in fist out buffer, Support for 4 FIFO trigger stages.
  • Support MODEM modem signals CTS, DSR, RI, DCD, DTR, RTS, can be converted to RS232 level by 75232 chip.
  • Supports hardware flow control signals CTS and RTS automatic handshake and automatic transmission rate control, compatible with TL16C550C.
  • Supports serial frame error detection and supports Break line interval detection.
  • Support full-duplex and half-duplex serial communication, provide RTS serial port sending status signal to support RS485 transceiver automatic switching.
  • Built-in SIR infrared codec, supports IrDA infrared communication from 2400bps to 115200bps baud rate.
  • Built-in clock oscillator, supports crystals with a frequency range of 0.9216MHz to 32MHz,the default is 22.1184MHz crystal.
  • Two microcontroller interfaces are available: 8-bit passive parallel interface at 10MB speed and SPI serial interface at 3MB/24MHz speed.
  • The parallel interface consists of an 8-bit data bus, 4-bit address, 3-wire control: chip select input, write operation, and optional read operation.
  • The SPI serial interface includes SPI chip select, serial clock, serial input and output, and the SPI output can be connected in parallel with the input.
  • The interrupt output pin is an optional connection, active low, can be replaced by the interrupt flag bit in the Query Register.
  • Support 5V or 3.3V power supply voltage, support serial low-power sleep mode.
  • Available in QFP-44 and SSOP-20 lead-free packages, compatible with RoHS.

relation files

file name file content
CH423DS1.PDF CH423 datasheet. A remote I/O expander with 2-wire serial interface, used for 16 digital tube display or I/O expansion applications through two wires. The input terminal is a two-wire interface compatible with I2C, and the output terminal is an 8-bit bidirectional input/output port and a 16-bit high-current output port.
CH341DS1.PDF CH341 datasheet, USB bus converter chip with multiple communication interfaces, such as USB to serial port/parallel port/printer port/I2C interface etc. Drivers support for Windows/Linux/Android/Mac, etc. The datasheet is the description of USB to serial port and printer port.
CH340DS1.PDF CH340 datasheet, USB bus converter chip which converts USB to serial port, printer port, IrDA SIR etc. Integrated clock, supports various operating systems, chip information can be customized, this datasheet is about USB to serial port and USB to Infrared Adapter SIR.
CH438DS1.PDF CH438 datasheet. CH438 is an 8-UART extension chip. Each UART receive/transmit has independent 128-byte FIFO. The maximum baud rate is 4Mbps. It supports hardware flow control, compatible with 16C550/16C750. It provides 8-bit parallel interface, used for MCU 8-UART extension.