ISL3179E/ISL3180E RS-485/RS-422 Transceivers Renesas ISL3179E/ISL3180E High ESD Protected RS-485/RS-422 Transceivers are 3.3V powered, single transceivers that meet both the RS-485 and RS-422 standards for balanced communication. Each of the Transcievers has low bus currents (+220μA/-150μA), so they present a “1/5 unit load” to the RS-485 bus. This allows up to 160 transceivers on the network without violating the RS-485 specification’s 32 unit load maximum, and without using repeaters.