IL3285/IL3222

IsoLoop

® is a registered trademark of NVE Corporation.

*U.S. Patent numbers 5,831,426; 6,300,617 and others.

REV. S

NVE Corporation

11409 Valley View Road, Eden Prairie, MN 55344-3617

(952) 829-9217

www.nve.com

YouTube.com/NveCorporation

iso-apps@nve.com

Fractional Load Passive Input RS-485 and RS-422 Isolated Transceivers

Functional Diagrams

IL3285 Truth Table

VID (A-B)

DE

RE

R

D

Mode

Notes

≥ 200 mV

L

L

H

X

Receive

≤−200mV

L

L

L

X

Open

L

L

H

X

A/B failsafe

≥ 1.5 V

H

L

H

H

Drive

R reads back

D information

≤−1.5 V

H

L

L

L

≥ 1.5 V

H

H

Z

H

R tri-state

(no output)

≤−1.5 V

H

H

Z

L

X

L

H

Z

X

Disabled

R tri-state;

A/B failsafe

Z = High Impedance

X = Irrelevant

* “H”=no coil-current flowing; “L”=coil current.

IL3222 Receiver

RE

R

V(A-B)

H

Z

X

L

H

≥ 200 mV

L

L

≤−200 mV

L

H

Open

IL3222 Driver

DE

D

V(Y-Z)

L

X

Z

H

H

≥ 2 V

H

L

≤−2 V

Features

•

3 V to 5 V power supplies

•

5 Mbps data rate

•

⅛ unit load

•

15 kV bus ESD protection

•

20 kV/µs typical common mode rejection

•

No carrier or clock for low EMI emissions and susceptibility

•

−40 °C to +85 °C temperature range

•

Thermal shutdown protection

•

2500 VRMS isolation

•

IEC 60747-17 (VDE 0884-17):2021-10; UL 1577

•

0.15" or 0.3" True 8™ mm 16-pin SOIC packages

Applications

•

High node-count networks

•

Security networks

•

Building environmental controls

•

Industrial control networks

•

Gaming systems

Description

The IL3285 and IL3222 are galvanically isolated,

differential bus transceivers designed for bidirectional data

communication over balanced transmission lines. The

devices use NVE’s patented* IsoLoop spintronic Giant

Magnetoresistance (GMR) technology. The IL3285 delivers

at least 1.5 V into a 54 Ω load, and the IL3222 at least 2 V

into a 100 Ω load for excellent data integrity over long

cables. These devices are also compatible with 3.3 V input

supplies, allowing interface to standard microcontrollers

without additional level shifting.

A unique ceramic/polymer composite barrier provides

excellent isolation and virtually unlimited barrier life.

Both the IL3285 and IL3222 have current limiting and

thermal shutdown features to protect against output short

circuits and bus contentions that may cause excessive power

dissipation. The receivers also incorporate a “fail-safe if

open” design, ensuring a logic high on R if the bus lines are

disconnected or “floating.”

Receiver input resistance of 96 kΩ is eight times the

RS-485 “Unit Load” (UL) minimum of 12 kΩ. Thus these

products are known as “one-eighth UL” transceivers. There

can be up to 256 on a network while still complying with

the RS-485 loading specification.

Selection Table

Model

Full/Half

Duplex

No. of Devices

Allowed on Bus

Data Rate

Mbps

Fail-Safe

IL3285

half

256

5

yes

IL3222

full

256

5

yes

R

RE

A

B

Z

R

RE

Y

IL3222

IL3285

A

B

V

COIL2

V

COIL1

V

COIL1

V

COIL2

DE

D

DE

D