THVD4431A is a highly integrated and robust Multiprotocol transceiver supporting RS-232, RS-422 and RS-485 physical layers. The device has three transmitters and five receivers to enable 3T5R RS-232 port. The device also integrates one transmitter and one receiver to enable half and full duplex RS-485 port. MODE selection pins enable shared bus and logic pins for the protocols to share a common single connector. Integrated termination for RS-485 bus pins and for RS-232 receiver inputs need no external components to realize a fully-functional communication port. The device has a slew rate select feature that enables the device for use at two maximum speeds based on the SLR pin setting.

The device features integrated Level 4 IEC ESD protection, eliminating the need for external system-level protection components. Diagnostic loopback mode for both RS-232 and RS-485 is provided to check for logic to bus and bus to logic path functional integrity and check for cable and connector shorts. In addition, the RS-485 receiver fail-safe feature drives logic high on received logic output when the bus inputs are open or shorted together or when the bus is idle. Shutdown mode consumes ultra-low current (10µA typical), which is good for power-sensitive applications. The device needs 3 to 5.5V supply that powers the charge pump for RS-232 and the drivers or receivers for both RS-232 and RS-485. A separate logic supply VIO (1.65V to 5.5V) enables interface with low level microcontrollers.