_

+

+

_

OSC

+

PWM

BIAS

POR

ISO722

Only

Filter

PulseWidth

Demodulation

CarrierDetect

_

+

_

+

Input

+

Filter

DataMUX

ACDetect

3-State

OutputBuffer

IN

EN

IsolationBarrier

DCChannel

ACChannel

FUNCTION DIAGRAM

OUT

POR

ISO721, ISO721M

ISO722, ISO722M

www.ti.com

SLLS629I – JANUARY 2006 – REVISED FEBRUARY 2010

3.3-V / 5-V HIGH-SPEED DIGITAL ISOLATORS

Check for Samples: ISO721, ISO721M, ISO722, ISO722M

1

FEATURES

DESCRIPTION

23

•

–

UL 1577, IEC 60747-5-2 (VDE 0884, Rev. 2)

The ISO721, ISO721M, ISO722, and ISO722M are

digital isolators with a logic input and output buffer

IEC 61010-1, IEC 60950-1 and CSA

Approved

barrier. This barrier provides galvanic isolation of up

–

50 kV/µs Transient Immunity Typical

to 4000 V. Used in conjunction with isolated power

•

Signaling Rate 0 Mbps to 150 Mbps

supplies, these devices prevent noise currents on a

data bus or other circuits from entering the local

–

Low Propagation Delay

ground, and interfering with or damaging sensitive

–

Low Pulse Skew (Pulse-Width Distortion)

circuitry.

•

Low-Power Sleep Mode

A binary input signal is conditioned, translated to a

•

High Electromagnetic Immunity

balanced signal, then differentiated by the capacitive

•

Low Input-Current Requirement

isolation barrier. Across the isolation barrier, a

differential comparator receives the logic transition

•

Failsafe Output

information, then sets or resets a flip-flop and the

•

Drop-In Replacement for Most Opto and

output circuit accordingly. A periodic update pulse is

Magnetic Isolators

sent across the barrier to ensure the proper dc level

of the output. If this dc-refresh pulse is not received

APPLICATIONS

for more than 4 ms, the input is assumed to be

•

Industrial Fieldbus

unpowered or not being actively driven, and the

failsafe circuit drives the output to a logic high state.

–

Modbus

–

Profibus

–

DeviceNet™ Data Buses

–

Smart Distributed Systems ( SDS™)

•

Computer Peripheral Interface

•

Servo Control Interface

•

Data Acquisition

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

SDS is a trademark of Honeywell.

3

DeviceNet is a trademark of Open Devicenet Vendors Association, Inc.

PRODUCTION DATA information is current as of publication date.

Copyright © 2006–2010, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.