LTM2881

1

2881fe

TYPICAL APPLICATION

DESCRIPTION

Complete Isolated

RS485/RS422 µModule

Transceiver + Power

components are required. A single supply powers both

sides of the interface through an integrated, isolated, low

noise, efficient 5V output DC/DC converter.

Coupled inductors and an isolation power transformer

and the logic interface. This device is ideal for systems

where the ground loop is broken allowing for large com-

mon mode voltage variation. Uninterrupted communica-

tion is guaranteed for common mode transients greater

than 30kV/μs.

Maximum data rates are 20Mbps or 250kbps in slew

limited mode. Transmit data, DI and receive data, RO, are

implemented with event driven low jitter processing. The

receiver has a one-eighth unit load supporting up to 256

nodes per bus. A logic supply pin allows easy interfacing

with different logic levels from 1.62V to 5.5V, independent

of the main supply.

Enhanced ESD protection allows this part to withstand up

to ±15kV (human body model) on the transceiver interface

pins to isolated supplies and ±10kV through the isolation

barrier to logic supplies without latch-up or damage.

L, LT, LTC, LTM, Linear Technology, the Linear logo and μModule are registered trademarks of

Linear Technology Corporation. All other trademarks are the property of their respective owners.

Isolated Half-Duplex RS485 μModule Transceiver

FEATURES

APPLICATIONS

UL Recognized

®

File #E151738

× 11.25mm)

Surface Mount BGA and LGA Packages

LTM2881 Operating Through 35kV/μs CM Transients

2881 TA01

TWISTED-PAIR

CABLE

AVAILABLE CURRENT:

150mA (LTM2881-5)

100mA (LTM2881-3)

A

5V

RO

TE

RE

DE

DI

GND

GND2

3.3V (LTM2881-3)

5V (LTM2881-5)

LTM2881

B

Y

Z

PWR

2881 TA01a

500V/DIV

50ns/DIV

1V/DIV

1V/DIV

DI

MULTIPLE SWEEPS

OF COMMON MODE

TRANSIENTS

RO