STMicro transceivers also function as level translators

STMicroelectronics has introduced a pair of low-power, high-speed transceivers for RS-485 and RS-422 communications in multi-point transmission networks and in LANs in control system, and are also suitable as level translators and transceivers in EMI-sensitive applications.

Intended for data rates of up to 25Mbps, the ST490A full-duplex and ST485A half-duplex transceivers contain one driver and one receiver. This setup allows them to draw a typical current of 5mA when unloaded or full loaded with disabled drivers.

Each driver is short circuit current limited and is protected against excessive power dissipation by thermal shutdown circuitry that puts the driver outputs into a high-impedance state. The driver can also maintain high impedance when tri-stated or when the power is off. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit.

The ICs operate from a single 5V supply and feature a common-mode input voltage range of -7V to 12V with a typical input hysteresis of 70mV. They are available in 8-pin DIP or SO08 packages and are protected from static discharges of up to 4kV.