Description

The ADM1490E / ADM1491E are RS-485/RS-422 transceivers with ±8 kV ESD protection and are suitable for high speed, full-duplex communication on multipoint transmission lines. In particular, the ADM1490E/ADM1491E are designed for use in motor control applications requiring communications at data rates up to 16 Mbps.The ADM1490E / ADM1491E are designed for balanced transmission lines and comply with TIA/EIA-485-A-98. The devices each have a 12 kΩ receiver input impedance for unit load RS-485 operation, allowing up to 32 nodes on the bus.The differential transmitter outputs and receiver inputs feature electrostatic discharge circuitry that provides protection to ±8 kV using the human body model (HBM).The ADM1490E / ADM1491E operate from a single 5 V power supply. Excessive power dissipation caused by bus contention or output shorting is prevented by short-circuit protection and thermal circuitry. Short-circuit protection circuits limit the maximum output current to ±250 mA during fault conditions. A thermal shutdown circuit senses if the die temperature rises above 150°C and forces the driver outputs into a high impedance state under this condition.The receiver of the ADM1490E / ADM1491E contains a fail-safe feature that results in a logic high output state if the inputs are unconnected (floating).The ADM1490E / ADM1491E feature extremely fast and closely matched switching times. Minimal driver propagation delays permit transmission at data rates up to 16 Mbps, and low skew minimizes EMI interference.The ADM1490E/ADM1491E are fully specified over the commercial and industrial temperature ranges. The ADM1490E is available in two packages: a narrow body, 8-lead SOIC and an 8-lead MSOP. The ADM1491E is also available in two packages: a narrow body, 14-lead SOIC and a 10-lead MSOP.APPLICATIONS RS-485/RS-422 interfaces Industrial field networks High data rate motor control Multipoint data transmission systems Single-ended-to-differential signal conversion