DATASHEET
ISL81334, ISL41334
±15kV ESD Protected, Two Port, Dual Protocol Transceivers
FN6202
Rev.4.00
Mar 24, 2017
The ISL81334 and ISL41334 are two-port interface ICs in
Features
which each port can be independently configured as a single
RS-485, RS-422 transceiver, or as a dual (2 Tx, 2 Rx) RS-232
transceiver. With both ports set to the same mode, two
RS-485, RS-422 transceivers, or four RS-232 transceivers are
available.
• ±15kV (HBM) ESD protected bus pins (RS-232 or RS-485)
• Two independent ports, each user selectable for RS-232
(2 transceivers) or RS-485, RS-422 (1 transceiver)
• Single 5V (10% tolerance) supply
• Flow-through pinouts simplify board layouts
• Pb-Free (RoHS compliant)
If either port is in RS-232 mode, the onboard charge pump
generates RS-232 compliant ±5V Tx output levels from a
single V supply as low as 4.5V. Four small 0.1µF capacitors
CC
are required for the charge pump. The transceivers are RS-232
compliant, with the Rx inputs handling up to ±25V, and the Tx
outputs handling ±12V.
• Large (2.7V) differential V
OUT
in RS-485, RS-422 networks
for improved noise immunity
• Full fail-safe (open/short) Rx in RS-485, RS-422 mode
• Loopback mode facilitates board self-test functions
In RS-485 mode, the transceivers support both the RS-485
and RS-422 differential communication standards. The
receivers feature “full fail-safe” operation, so the Rx outputs
remain in a high state if the inputs are open or shorted
together. The transmitters support up to three data rates, two
of which are slew rate limited for problem-free
• User selectable RS-485 data rates (ISL41334 only)
- Fast speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Mbps
- Slew rate limited . . . . . . . . . . . . . . . . . . . . . . . . . . . 460kbps
- Slew rate limited . . . . . . . . . . . . . . . . . . . . . . . . . . . 115kbps
communications. The charge pump disables when both ports
are in RS-485 mode, thereby saving power, minimizing noise,
and eliminating the charge pump capacitors.
• Fast RS-232 data rate . . . . . . . . . . . . . . . . . . . . up to 650kbps
• Low current Shutdown mode . . . . . . . . . . . . . . . . . . . . . . 42µA
• QFN package saves board space (ISL41334 only)
Both RS-232 and RS-485 modes feature loopback and
shutdown functions. Loopback internally connects the Tx
outputs to the corresponding Rx input, to facilitate board level
self-test implementation. The outputs remain connected to the
loads during loopback, so connection problems (such as
shorted connectors or cables) can be detected. Shutdown
mode disables the Tx and Rx outputs, disables the charge
pumps, and places the IC in a low current (µA) mode.
• Logic supply pin (V ) eases operation in mixed supply
L
systems (ISL41334 only)
Applications
• Gaming applications (such as, slot machines)
• Single board computers
• Factory automation
The ISL41334 is a QFN packaged device that includes two
additional user selectable, lower speed, and edge rate options
for EMI-sensitive designs, or to allow longer bus lengths. It also
• Security networks
• Industrial/process control networks
• Level translators, such as RS-232 to RS-422
• Point of sale equipment
features a logic supply pin (V ) that sets the V level of logic
L
OH
outputs, and the switching points of logic inputs, to be
compatible with another supply voltage in mixed voltage
systems. The QFN also adds active low Rx enable pins to
increase design flexibility, allowing Tx/Rx direction control,
through a single signal per port, by connecting the
corresponding DE and RXEN pins together.
• Dual channel RS-485 interfaces
Related Literature
• For a full list of related documents, visit our website
- ISL81334, ISL41334 product pages
For a single port version of these devices, please see the
ISL81387, ISL41387 datasheet.
FN6202 Rev.4.00
Mar 24, 2017
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