Rugged RS485/RS422 transceivers operate as fast as 20 megabytes per second with low EMI

Linear Technology Corp. in Milpitas, Calif., is offering the LTC2856/LTC2857/LTC2858 low-power RS485/422 transceivers, operating on 5-volt supplies. The LTC2856-1, LTC2857-1, and LTC2858-1 operate at maximum data rates of 20 megabytes per second, while the LTC2856-2, LTC2857-2, and LTC2858-2 feature 250-kilobits-per-second slew-rate-limited driver outputs to control high-frequency emission from equipment and data cables. Enhanced electrostatic discharge protection on the transceiver interface pins enables the integrated circuits to withstand plus-or-minus 15 kilovolts for ESD strikes (human body model) without latchup or damage. The receiver fail-safe feature further enhances the devices’ operation by guaranteeing a high output state under conditions of floating or shorted inputs. The receivers of the LTC2856/LTC2857/LTC2858 have a one-eighth unit load, supporting up to 256 devices on the bus, while the drivers of all ICs maintain a high output impedance over the entire common mode range when disabled or when the supply is removed. Excessive power dissipation caused by bus contention or a fault is prevented by current limiting all outputs and by thermal shutdown. For more information contact Linear Technology online at www.linear.com.