STR485ELVQT is a low power differential line transceiver for data transmission for standard RS485 applications in half-duplex mode. The data that enables signals which are compatible with 1.8V or 3.3V supplies. Two speeds are selectable through SLR pin which has fast data rate upto 20Mbps or slow data rate for extended cable running to 250kbps. The excessive power dissipation caused by bus contention or faults is prevented by thermal shutdown circuit that forces the driver outputs into a high impedance state. The receiver has a fail-safe feature, which guarantees a high output state when the inputs are left open, shorted or idle.