Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com
XR33032/35/38
WIDE SUPPLY 18V TOLERANT RS-485/RS-422 TRANSCEIVERS
FEBRUARY 2014 REV. 1.0.0
GENERAL DESCRIPTION
The XR33032/35/38 family of high performance half
duplex RS-485 transceivers are optimized to operate
over a wide range of supply voltage, from +2.8V to
+5.5V. The analog bus pins can withstand direct shorts
up to ±18V, and are protected against ESD events up
to ±15kV.
In an isolated application it may be more efficient to
use a remote power supply rather than generating an
isolated supply at every node. The XR33032/35/38
transceivers can operate with more than 2V IR drop in
the cable when utilizing a remote 5V power supply.
The transceivers draw less than 600µA, and typically
only 300µA when idling with the receivers active.
The receivers include full fail-safe circuitry, guarantee-
ing a logic-high receiver output when the receiver
inputs are open, shorted, or undriven. The receiver
input impedance is 96k (1/8 unit load), allowing up to
256 devices on the bus while preserving the full signal
margin.
The drivers are protected by short circuit detection as
well as thermal shutdown, and maintain high imped
-
ance in shutdown or when powered off. The XR33032
and XR33035 drivers are slew limited for reduced EMI
and error-free communication over long or untermi
-
nated data cables.
The DE and RE pins include hot swap circuitry to pre-
vent false transitions on the bus during power-up or
live insertion, and can enter a low current shutdown
mode (40nA typically) for extreme power savings.
FEATURES
+2.8V to +5.5V Operating Range
±18V Fault Tolerance on Analog Bus pins
Robust ESD (ElectroStatic Discharge) Protection:
■ ±15kV IEC 61000-4-2 Air Gap Discharge
■ ± 8kV IEC 61000-4-2 Contact Discharge
■ ±15kV Human Body Model
■ ± 4kV Human Body Model on non-bus pins
300µA Idle Current, 40nA Shutdown Current
Enhanced Receiver Fail-Safe Protection for Open,
Shorted, or Terminated but Idle Data Lines
Hot-Swap Glitch Protection on DE and RE Pins
Driver Short Circuit Current Limit and Thermal
Shutdown for Overload Protection
1/8
th
Unit Load Allows up to 256 Devices on Bus
Industry Standard 8 NSOIC Half Duplex Package
TYPICAL APPLICATIONS
Isolated Multipoint RS-485 Data Buses
Remote Nodes Powered by the Host
Building Automation and HVAC
Industrial Process Control Networks
Remote Utility Meter Reading
Energy Monitoring and Control
V
CC
B/Z
A/Y
GND
RO
RE
DE
DI
1
2
3
4
R
D
8
7
6
5
