An RS-485 bus consists of multiple transceivers connecting in parallel to a bus cable. To eliminate line reflections, each cable end is terminated with a termination resistor, R_T, whose value matches the characteristic impedance, Z₀, of the cable. This method, known as parallel termination, generally allows for higher data rates over longer cable length.

Figure 8-1 Typical RS-485 Network With Half-Duplex Transceivers

Figure 8-2 Typical RS-485 Network With Full-Duplex Transceivers

THVD4431 can be used in both networks (half and full duplex) and at all nodes (end node or middle nodes) since device has the configurability based on MODE2, MODE1, MODE0 pins and TERM_TX, TERM_RX pins.

THVD4431 also consists of three line drivers, five line receivers and dual charge pump circuit to enable RS-232 point-to-point serial communication. Full duplex transmission with hardware flow control is feasible with this device. This device provides the electrical interface between an asynchronous communication controller and the serial-port connector.

Figure 8-3 RS-232 serial communication