SP4082E
5V RS-485/RS-422 Transceivers
1/8th Unit Load, Slew-Rate Limited, ±15kV ESD-Protected
FEATURES
• 5.0V single supply operation
• Receiver failsafe on open or shorted lines
• /8th Unit Load, 256 transceivers on bus
• Robust ESD protection for RS-485 pins
±5kV Human Body Model
• Controlled driver slew rates
5kbps, Low EMI
•Driver short circuit current limit and
thermal shutdown for overload protection
•Industry standard package footprints
RO
1
RE
2
DE
3
DI
4
8 PIN NSOIC
SP4082E
Half Duplex
8
Vcc
7
B
6
A
5
GND
APPLICATIONS
• Motor Control
• Building Automation
• Security Systems
• Remote Meter Reading
• Long or un-terminated transmission lines
The SP4082E is designed for reliable, bidirectional communication on multipoint bus transmission
lines. The device contains one differential driver and one differential receiver. It is a half-duplex de-
vice. The device complys with TIA/EIA-485 and TIA/EIA-422 standards. Lead-free and RoHS compli-
ant packages are available.
This device is ruggedized for use in harsh operating conditions over the entire common-mode volt-
age range from -7V to +2V. Receivers are specially designed to fail-safe to a logic high output state
if the inputs are un-driven or shorted. All RS-485 bus-pins are protected against severe ESD events
up to ±15kV (Human Body Model). Drivers are protected from excess current flow caused by bus
contention or output short-circuits by both an internal current limit and a thermal-overload shutdown.
Devices are rated for industrial (-40 to +85ºC) operating temperatures. Receivers have exceptionally
high input impedance, which places only /8th the standard load on a shared bus. Up to 256 trans-
ceivers may coexist while preserving full signal margin.
The device operates from a single 5.0V power supply and draws negligible quiescent power. The
device has an independent enable and disable for the driver and receiver and will enter a low power
shutdown mode if both driver and receiver are disabled. All outputs maintain high impedance during
shutdown or when powered-off.
DESCRIPTION
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (50)6687000 • Fax (50)668-707 • www.exar.com
SP4082E_00_22007
EXAR [ EXAR CORPORATION ]
