Intersil’s ISL3179E and ISL3180E are high ESD Protected (see Table 1 below), 3.3V powered, single transceivers that meet both the RS-485 and RS-422 standards for balanced communication. Each device has low bus currents (+220μA/-150μA), so it presents 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.

Receiver (Rx) inputs feature a “Full Fail-Safe” design, which ensures a logic high Rx output if Rx inputs are floating, shorted, or terminated but undriven.

The ISL3180E is configured for full duplex applications. The ISL3179E half duplex version multiplexes the Rx inputs and Tx outputs to allow a transceiver with an output disable function in 8 Ld packages.

Hot Plug circuitry ensures that the Tx and Rx outputs remain in a high impedance state while the power supply stabilizes.

• High ESD Protection on RS-485 I/O Pins
  • ISL3179E ±16.5kV IEC61000
  • ISL3180E ±12kV HBM
  • Class 3 HBM ESD Level on all Other Pins >9kV
• Specified for +125°C Operation
• High Data Rates up to 40Mbps
• 5V Tolerant Logic Inputs
• 1/5 Unit Load Allows up to 160 Devices on the Bus
• Full Fail-Safe (Open, Shorted, Terminated/Undriven) Receiver
• Hot Plug - Tx and Rx Outputs Remain Three-State During Power-Up
• Low Quiescent Current 4mA (Max)
• Low Current Shutdown Mode 1μA (Max)
• -7V to +12V Common Mode Input Voltage Range
• Three-State Rx and Tx Outputs
• 16/16.5ns (Max) Tx/Rx Propagation Delays; 1.5ns (Max) Skew
• Operates from a Single +3.3V Supply (10% Tolerance)
• Current Limiting and Thermal Shutdown for driver Overload Protection
• Pb-Free (RoHS Compliant)

• Motor Controller/Position Encoder Systems
• Factory Automation
• Field Bus Networks
• Security Networks
• Building Environmental Control Systems
• Industrial/Process Control Networks