Intersil’s ISL3159E is a ±15kV IEC61000 ESD protected, 5V
powered, single transceiver that meets both the RS-485 and
RS-422 standards for balanced communication. It also
features the larger output voltage and higher data rate - up to
40Mbps - required by high speed PROFIBUS applications, and
is offered in industrial and extended Industrial (-40°C to
+125°C) temperature ranges. The low bus currents
(+220µA/-150µA) 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 load limit and without
using repeaters.
This transceiver requires a 5V ±10% tolerance supply, and
delivers at least a 2.1V differential output voltage over this
supply range. This translates into better noise immunity (data
integrity), longer reach, or the ability to drive up to six 120Ω
terminations in “star” or other nonstandard bus topologies, at
the exceptional 40Mbps data rate.
SCSI applications benefit from the ISL3159’s low receiver and
transmitter part-to-part skews, which make it perfect for high
speed parallel applications where large numbers of bits must
be simultaneously captured. The low bit-to-bit skew eases the
timing constraints on the data latching signal.
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. Rx outputs feature high
drive levels (typically >30mA at VOL = 1V) to ease the design of
optically isolated interfaces.
Hot plug circuitry ensures that the Tx and Rx outputs remain in
a high impedance state while the power supply stabilizes.
Driver (Tx) outputs are short-circuit protected, even for voltages
exceeding the power supply voltage. Additionally, on-chip
thermal shutdown circuitry disables the Tx outputs to prevent
damage if power dissipation becomes excessive.

Features
• IEC61000 ESD protection on RS-485 I/O Pins . . . . . . ±15kV
- Class 3 HBM ESD level on all other pins . . . . . . . . . . . >9kV
• Large differential VOUT . . . . . . . . . . . . . . . . . . . 2.8V into 54Ω
Better noise immunity, or drive up to 6 terminations
• High data rates. . . . . . . . . . . . . . . . . . . . . . . . . . up to 40Mbps
• Specified for +125°C operation
• 11/13ns (max) Tx/Rx propagation delays; 1.5ns (max) skew
• 1/5 unit load allows up to 160 devices on the bus
• Full fail-safe (open, shorted, terminated/undriven) receiver
• High Rx IOL to drive optocouplers for isolated applications
• Hot plug - Tx and Rx outputs remain three-state during
power-up
• Low quiescent supply current. . . . . . . . . . . . . . . . . . . . . . 4mA
• Low current shutdown mode . . . . . . . . . . . . . . . . . . . . . . . 1µA
• -7V to +12V common-mode input voltage range
• Three-state Rx and Tx outputs
• Operates from a single +5V supply (10% tolerance)
• Current limiting and thermal shutdown for driver overload
protection
• Pb-free (RoHS compliant)

Applications
• PROFIBUS DP and FMS networks
• SCSI “fast 40” drivers and receivers
• Motor controller/position encoder systems
• Factory automation
• Field bus networks
• Security networks
• Building environmental control systems
• Industrial/process control networks