a
15 kV ESD Protected, EMC Compliant
Slew Rate Limited, EIA RS-485 Transceiver
ADM483E
FUNCTIONAL BLOCK DIAGRAM
ADM483E
FEATURES
Robust RS-485 Transceiver
15 kV ESD Protection Using HBM
2 kV EFT Protection Meets IEC1000-4-4
High EM Immunity Meets IEC1000-4-3
Reduced Slew Rate for Low EM Interference
250 kbps Data Rate
Single +5 V 10% Supply
–7 V to +12 V Bus Common-Mode Range
12 k Input Impedance
Short Circuit Protection
Excellent Noise Immunity
36 A Supply Current
0.1 A Shutdown Current
APPLICATIONS
Low Power RS-485 Systems
Electrically Harsh Environments
EMI Sensitive Applications
DTE-DCE Interface
Packet Switching
Local Area Networks
RO
RE
DE
R
B
A
D
DI
GENERAL DESCRIPTION
The ADM483E is a robust, low power differential line trans-
ceiver suitable for communication on multipoint bus transmis-
sion lines. Internal protection against electrostatic discharge
(ESD), electrical fast transient (EFT) and electromagnetic
immunity (EMI) allows operation in electrically harsh environ-
ments. ESD protection on the I-O lines meets
±
15 kV when
tested using the Human Body Model. EFT protection meets
±
2 kV in accordance with IEC1000-4-4, while EMI immunity is
in excess of 10 V/m meeting IEC1000-4-3.
The level of unwanted emissions is also carefully controlled
using slew limiting on the driver outputs. This reduces reflec-
tions with improperly terminated cables and also minimizes
electromagnetic interference. The controlled slew rate limits the
data rate to 250 kbps.
The ADM483E is intended for balanced data transmission and
complies with both EIA Standards RS-485 and RS-422. It
contains a differential line driver and a differential line receiver
and is suitable for half duplex data transmission, as the driver
and receiver share the same differential pins.
The input impedance on the ADM483E is 12 kΩ, allowing up
to 32 transceivers on the bus.
The ADM483E operates from a single +5 V
±
10% power sup-
ply. Excessive power dissipation caused by bus contention or by
output shorting is prevented by a thermal shutdown circuit. This
feature forces the driver output into a high impedance state if,
during fault conditions, a significant temperature increase is
detected in the internal driver circuitry.
The receiver contains a fail-safe feature that results in a logic
high output state if the inputs are unconnected (floating).
The ADM483E is fabricated on BiCMOS, an advanced mixed
technology process combining low power CMOS with robust
bipolar technology.
It is fully specified over the industrial temperature range and is
available in 8-lead DIP and SOIC packages.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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Tel: 617/329-4700
World Wide Web Site: http://www.analog.com
Fax: 617/326-8703
© Analog Devices, Inc., 1997
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