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ADM488/ADM489
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 World Wide Web Site: http://www.analog.com
Fax: 617/326-8703 © Analog Devices, Inc., 1997
Full-Duplex, Low Power,
Slew Rate Limited, EIA RS-485 Transceivers
FUNCTIONAL BLOCK DIAGRAMS
FEATURES
Meets EIA RS-485 Standard
250 kbps Data Rate
Single +5 V 6 10% Supply
–7 V to +12 V Bus Common-Mode Range
12 kV Input Impedance
2 kV EFT Protection Meets IEC1000-4-4
High EM Immunity Meets IEC1000-4-3
Reduced Slew Rate for Low EM Interference
Short Circuit Protection
Excellent Noise Immunity
30 mA Supply Current
APPLICATIONS
Low Power RS-485 Systems
DTE-DCE Interface
Packet Switching
Local Area Networks
Data Concentration
Data Multiplexers
Integrated Services Digital Network (ISDN)
GENERAL DESCRIPTION
The ADM488 and ADM489 are low power differential line
transceiver suitable for communication on multipoint bus trans-
mission lines.
They are intended for balanced data transmission and comply
with both EIA Standards RS-485 and RS-422. Both products
contains a single differential line driver and a single differential
line receiver making them suitable for full duplex data transfer.
The ADM489 contains an additional receiver and driver enable
control.
The input impedance is 12 kΩ, allowing 32 transceivers to be
connected on the bus.
The ADM488/ADM489 operates from a single +5 V ± 10%
power supply. Excessive power dissipation caused by bus con-
tention or by output shorting is prevented by a thermal shut-
down circuit. This feature forces the driver output into a high
impedance state if during fault conditions a significant tempera-
ture 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 ADM488/ADM489 is fabricated on BiCMOS, an ad-
vanced mixed technology process combining low power CMOS
with fast switching bipolar technology.
The ADM488/ADM489 is fully specified over the industrial
temperature range and is available in DIP, SOIC and TSSOP
packages.
ADM488
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ADM489
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