1FEATURES

23· Controlled Baseline

– One Assembly Site

– One Test Site

– One Fabrication Site

· Extended Temperature Performance of

–55°C to 125°C

· Enhanced Diminishing Manufacturing Sources

(DMS) Support

· Enhanced Product-Change Notification

· Qualification Pedigree (1)

· 4000-V(peak) Isolation

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

IEC 61010-1

– 50-kV/ms Transient Immunity Typical

· Signaling Rate 0 Mbps to 150 Mbps

– Low Propagation Delay

– Low Pulse Skew (Pulse-Width Distortion)

· Low-Power Sleep Mode

· High Electromagnetic Immunity

· Low Input Current Requirement

· Failsafe Output

· Drop-In Replacement for Most Opto and

Magnetic Isolators

APPLICATIONS

· Industrial Fieldbus

– Modbus

– Profibus

– DeviceNet™ Data Buses

– Smart Distributed Systems (SDS™)

· Computer Peripheral Interface

· Servo Control Interface

· Data Acquisition

DESCRIPTION/ORDER INFORMATION

The ISO721, ISO721M, ISO722, and ISO722M are digital isolators with a logic input and output buffer separated

by a silicon oxide (SiO2) insulation barrier. This barrier provides galvanic isolation of up to 4000 V. Used in

conjunction with isolated power supplies, these devices prevent noise currents on a data bus or other circuits

from entering the local ground, and interfering with or damaging sensitive circuitry.

A binary input signal is conditioned, translated to a balanced signal, then differentiated by the capacitive isolation

barrier. Across the isolation barrier, a differential comparator receives the logic transition information, then sets or

resets a flip-flop and the output circuit accordingly. A periodic update pulse is sent across the barrier to ensure

the proper dc level of the output. If this dc-refresh pulse is not received for more than 4 ms, the input is assumed

to be unpowered or not being actively driven, and the failsafe circuit drives the output to a logic high state.