5 kV rms Signal and Power Isolated
RS-485 Transceiver with ± ±5 kV ꢀSꢁ
AꢁM2682ꢀ/AꢁM2687ꢀ
FEATURES
FUNCTIONAL BLOCK DIAGRAM
V
V
ISOOUT
CC
5 kV rms isolated RS-485/RS-422 transceiver, configurable as
half or full duplex
isoPower DC-TO-DC CONVERTER
isoPower integrated isolated dc-to-dc converter
15 kV ESD protection on RS-485 input/output pins
Complies with ANSI/TIA/EIA-485-A-98 and ISO 8482:1987(E)
Data rate: 16 Mbps (ADM2682E), 500 kbps (ADM2687E)
5 V or 3.3 V operation
OSCILLATOR
RECTIFIER
V
ISOIN
REGULATOR
Connect up to 256 nodes on one bus
Open- and short-circuit, fail-safe receiver inputs
High common-mode transient immunity: >25 kV/μs
Thermal shutdown protection
TRANSCEIVER
D
DIGITAL ISOLATION iCoupler
Y
Z
ENCODE
DECODE
DECODE
ENCODE
TxD
DE
Safety and regulatory approvals
UL recognition (pending)
5000 V rms for 1 minute per UL 1577
ENCODE
DECODE
CSA Component Acceptance Notice #5A (pending)
IEC 60601-1: 400 V rms (basic), 250 V rms (reinforced)
IEC 60950-1: 600 V rms (basic), 380 V rms (reinforced)
VDE Certificates of Conformity (pending)
DIN EN 60747-5-2 (VDE 0884 Part 2): 2003-01
A
B
RxD
R
RE
ADM2682E/ADM2687E
V
IORM = 846 V peak
Operating temperature range: −40°C to +85°C
16-lead wide-body SOIC with >8 mm creepage and clearance
GND
GND
2
1
ISOLATION
BARRIER
Figure 1.
APPLICATIONS
Isolated RS-485/RS-422 interfaces
Industrial field networks
Multipoint data transmission systems
GENERAL DESCRIPTION
The ADM2682E/ADM2687E are fully integrated 5 kV rms
signal and power isolated data transceivers with ±±5 kV EꢀD
protection and are suitable for high speed communication on
multipoint transmission lines. The ADM2682E/ADM2687E
include an integrated 5 kV rms isolated dc-to-dc power supply
that eliminates the need for an external dc-to-dc isolation block.
The ADM2682E/ADM2687E drivers have an active high enable.
An active low receiver enable is also provided, which causes the
receiver output to enter a high impedance state when disabled.
The devices have current limiting and thermal shutdown
features to protect against output short circuits and situations
where bus contention may cause excessive power dissipation.
The parts are fully specified over the industrial temperature
range and are available in a highly integrated, ±6-lead, wide-
body ꢀOIC package with >8 mm creepage and clearance.
They are designed for balanced transmission lines and comply
with ANꢀI/TIA/EIA-485-A-98 and IꢀO 8482:±987(E).
The devices integrate Analog Devices, Inc., iCoupler® technology to
combine a 3-channel isolator, a three-state differential line driver, a
differential input receiver, and Analog Devices isoPower® dc-to-dc
converter into a single package. The devices are powered by a
single 5 V or 3.3 V supply, realizing a fully integrated signal and
power isolated Rꢀ-485 solution.
The ADM2682E/ADM2687E contain isoPower technology that
uses high frequency switching elements to transfer power through
the transformer. ꢀpecial care must be taken during printed circuit
board (PCB) layout to meet emissions standards. Refer to
AN-097± Application Note, Recommendations for Control of
Radiated Emissions with isoPower Devices, for details on board
layout considerations.
Rev. 0
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