5 kV rms Signal and Power Isolated

RS-485 Transceiver with ±15 kV ESD

ADM2682E/ADM2687E

Rev. 0

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibilityis assumedbyAnalogDevicesforitsuse,norforanyinfringementsof patentsorother

rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

www.analog.com

Fax: 781.461.3113

©2011 Analog Devices, Inc. All rights reserved.

FEATURES

5 kV rms isolated RS-485/RS-422 transceiver, configurable as

half or full duplex

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

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

Safety and regulatory approvals

UL recognition (pending)

5000 V rms for 1 minute per UL 1577

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

Operating temperature range: −40°C to +85°C

16-lead wide-body SOIC with >8 mm creepage and clearance

APPLICATIONS

Isolated RS-485/RS-422 interfaces

Industrial field networks

Multipoint data transmission systems

FUNCTIONAL BLOCK DIAGRAM

ADM2682E/ADM2687E

TxD

A

B

Y

Z

DE

RxD

RE

DECODE

D

R

DECODE

ENCODE

OSCILLATOR

RECTIFIER

REGULATOR

isoPower DC-TO-DC CONVERTER

DIGITAL ISOLATION iCoupler

ENCODE

ENCODE

DECODE

TRANSCEIVER

ISOLATION

BARRIER

Figure 1.

GENERAL DESCRIPTION

The ADM2682E/ADM2687E are fully integrated 5 kV rms

signal and power isolated data transceivers with ±15 kV ESD

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.

They are designed for balanced transmission lines and comply

with ANSI/TIA/EIA-485-A-98 and ISO 8482:1987(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 RS-485 solution.

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, 16-lead, wide-

body SOIC package with >8 mm creepage and clearance.

The ADM2682E/ADM2687E contain isoPower technology that

uses high frequency switching elements to transfer power through

the transformer. Special care must be taken during printed circuit

board (PCB) layout to meet emissions standards. Refer to

AN-0971 Application Note, Recommendations for Control of

Radiated Emissions with isoPower Devices, for details on board

layout considerations.