The ISL3158AE is a BiCMOS, IEC61000 ESD protected, 5V powered, single transceiver that meets both the RS-485 and RS-422 standards for balanced communication. Each driver output and receiver input is protected against ±16. 5kV ESD strikes without latch-up. The ISL3158AE transmitter delivers exceptional differential output voltages (2. 4V min), into the RS-485 required 54Ω load, for better noise immunity or to allow up to eight 120Ω terminations in "star" or other non-standard bus topologies. This device has very low bus currents (+125µA/-75µA), so it presents a true "1/8 unit load" to the RS-485 bus. This allows up to 256 transceivers on the network without violating the RS-485 specification’s 32 unit load maximum, and 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). Hot Plug circuitry ensures that the Tx and Rx outputs remain in a high impedance state until the power supply has stabilized, and the Tx outputs are fully short circuit protected. The ISL3158AE is a half duplex version. It multiplexes the Rx inputs and Tx outputs to allow transceivers with output disable functions in an 8 Ld package.