The LTC1690 is a low power receiver/driver pair that is compatible with the requirements of RS485 and RS422. The receiver offers a fail-safe feature that guarantees a high receiver output state when the inputs are left open, shorted together or terminated with no signal present. No external components are required to ensure the high receiver output state. Separate driver output and receiver input pins allow full duplex operation. Excessive power dissipation caused by bus contention or faults is prevented by a thermal shut- down circuit which forces the driver outputs into a high impedance state. The LTC1690 is fully specified over the commercial and industrial temperature ranges. The LTC1690 is available in 8-Pin SO, MSOP and PDIP packages.