Intersil’s ISL3179E and ISL3180E are high ESD Protected (see
Table 2), 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.

Features
• High ESD protection on RS-485 I/O pins
- ISL3179E. . . . . . . . . . . . . . . . . . . . . . . . . ±16.5kV IEC61000
- ISL3180E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±12kV HBM
- Class 3 HBM level on all other pins (ISL3179E) . . . . . >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)

Applications
• Motor controller/position encoder systems
• Factory automation
• Field bus networks
• Security networks
• Building environmental control systems
• Industrial/process control networks