
500 kbps, ESD Protected, Half-/Full-Duplex,
iCoupler, Isolated RS-485 Transceiver
Data Sheet
Rev. D
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FEATURES
Isolated, RS-485/RS-422 transceiver, configurable as half- or
full-duplex
±15 kV ESD protection on RS-485 input/output pins
500 kbps data rate
Complies with ANSI TIA/EIA RS-485-A-1998 and
ISO 8482: 1987(E)
Suitable for 5 V or 3.3 V operation (VDD1)
High common-mode transient immunity: >25 kV/μs
True fail-safe receiver inputs
256 nodes on the bus
Thermal shutdown protection
Safety and regulatory approvals
UL recognition
5000 V rms isolation voltage for 1 minute per UL1577
VDE certificate of conformity
DIN V VDE V 0884-10 (VDE V 0884-10): 2006-12
Reinforced insulation, VIORM = 849 VPEAK
CSA Component Acceptance Notice #5A
IEC 60950-1: 380 V rms (reinforced)
Operating temperature range: 40°C to +85°C
Wide body, 16-lead SOIC package
APPLICATIONS
Isolated RS-485/RS-422 interfaces
Industrial field networks
INTERBUS
Multipoint data transmission systems
FUNCTIONAL BLOCK DIAGRAM
ADM2484E
G
A
L
V
ANI
C
I
S
O
L
A
T
IO
N
VDD1
GND1
VDD2
GND2
Y
Z
TxD
DE
A
B
RxD
RE
06
98
4-
0
01
Figure 1.
GENERAL DESCRIPTION
ESD protection suitable for high speed, half- or full-duplex
communication on multipoint transmission lines. For half-
duplex operation, the transmitter outputs and receiver inputs
share the same transmission line. Transmitter Output Pin Y
links externally to Receiver Input Pin A, and Transmitter
Output Pin Z links externally to Receiver Input Pin B.
Designed for balanced transmission lines, the
ADM2484Ecomplies with ANSI TIA/EIA RS-485-A-1998 and ISO 8482:
1987(E). The device employs Analog Devices, Inc., iCoupler
technology to combine a 3-channel isolator, a three-state
differential line driver, and a differential input receiver into a
single package.
The differential transmitter outputs and receiver inputs feature
electrostatic discharge circuitry that provides protection up to
±15 kV using the human body model (HBM). The logic side of
the device can be powered with either a 5 V or a 3.3 V supply,
whereas the bus side requires an isolated 3.3 V supply.
The device has current-limiting and thermal shutdown features
to protect against output short circuits and situations where bus
contention causes excessive power dissipation.