ST485A/490A: Very High Speed,
Low Power RS-485/422 Transceiver

ST485A Product Page
ST490A Product Page

These new devices are low-power, high-speed transceivers for RS-485 and RS-422 communication. Each part contains one driver and one receiver. These transceivers draw 3mA (typ.) of supply current when unloaded or fully loaded with disabled drivers. They operate from a single 5V supply. The driver is short-circuit current limited and is protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuited.