LTC2854/LTC2855

1

285455fa

FEATURES

DESCRIPTION

APPLICATIONS

TYPICAL APPLICATION

PRODUCT SELECTION GUIDE

3.3V 20Mbps RS485/RS422

Transceivers with Integrated

Switchable Termination

RS485/RS422 transceivers operating on 3.3V supplies.

The receiver includes a logic-selectable 120Ω termina-

tion, one-eighth unit load supporting up to 256 nodes per

bus (C, I-Grade), and a failsafe feature that guarantees a

high output state under conditions of floating or shorted

inputs.

The driver maintains a high output impedance over the

entire common mode range when disabled or when the

supply is removed. Excessive power dissipation caused by

bus contention or a fault is prevented by current limiting

all outputs and by a thermal shutdown.

Enhanced ESD protection allows the LTC2854 to withstand

±25kV (human body model) and the LTC2855 to withstand

±15kV on the transceiver interface pins without latchup

or damage.

■

Low Power RS485/RS422 Transceiver

■

Level Translator

■

Backplane Transceiver

■

Integrated, Logic-Selectable 120Ω Termination

Resistor

■

3.3V Supply Voltage

■

20Mbps Maximum Data Rate

■

No Damage or Latchup Up to ±25kV HBM

■

High Input Impedance Supports 256 Nodes

(C, I-Grade)

■

Operation Up to 125°C (H-Grade)

■

Guaranteed Failsafe Receiver Operation Over the

Entire Common Mode Range

■

Current Limited Drivers and Thermal Shutdown

■

Delayed Micropower Shutdown: 5μA Maximum

(C, I-Grade)

■

Power Up/Down Glitch-Free Driver Outputs

■

Low Operating Current: 370μA Typical in

Receive Mode

■

Compatible with TIA/EIA-485-A Specifications

■

Available in 10-Pin 3mm × 3mm DFN, 12-Pin

4mm × 3mm DFN and 16-Pin SSOP Packages

PART NUMBER

DUPLEX

PACKAGE

LTC2854

HALF

DFN-10

LTC2855

FULL

SSOP-16, DFN-12

RE

TE

RO

DE

DI

R

D

285455 TA01

LTC2854

120

Ω

RE

RO

TE

DE

DI

R

D

LTC2854

120

Ω

RE

RO

TE DE

DI

R

D

LTC2854

120

Ω

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

20ns/DIV

2V/DIV

285455 TA01b

A-B

B

A

DI