Single Transmitter/Receiver RS-422/RS-485 14-Pin SOIC

The ISL3156E ESD protected, 5V powered transceiver that meet the RS-485 and RS-422 standards for balanced communication. Driver outputs and receiver inputs are protected against ±16.5kV ESD strikes without latch-up. Transmitters in this family deliver exceptional differential output voltages (2.4V min), into the RS-485 required 54O load, for better noise immunity, or to allow up to eight 120O terminations in “star” topologies. These devices have very low bus currents so they present a true “1/8 unit load” to the RS-485 bus. This allows up to 256 transceivers on the network without using repeaters. Receiver (Rx) inputs feature a “Full Fail-Safe” design, which ensures a logic high Rx output if Rx inputs are floating, shorted, or on a terminated but undriven bus. Rx outputs feature high drive levels - typically 28mA @ VOL = 1V (to ease the design of optocoupled isolated interfaces). Half duplex (Rx inputs and Tx outputs multiplexed together) and full duplex pinouts are available. See Table 1 on page 2 for key features and configurations by device number.

• High Driver VOD 2.4V (Min) @ RD = 54O Better Noise Immunity, or Drive Up to 8 Terminations
• ±16.5kV IEC61000 ESD Protection on I/O Bus Pins
• High Transient Overvoltage Tolerance ±100V
• Full Fail-safe (Open, Short, Terminated) Receivers
• High Rx IOL for Opto-Couplers in Isolated Designs
• Hot Plug Circuitry - Tx and Rx Outputs Remain Three-State During Power-up/Power-down
• True 1/8 Unit Load for up to 256 Devices on the Bus
• High Data Rates up to 20Mbps
• Low Quiescent Supply Current 600µA Ultra Low Shutdown Supply Current 70nA