The STR485 is a low power differential line transceiver for data transmission standard RS485 applications in half-duplex mode. Data and enable signals are compatible with 1.8 V or 3.3 V supplies. Two speeds are selectable through SLR pin: fast data rate up to 20 Mbps or slow data rate for extended cable running to 250 kbps. 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.