LTC2859/LTC2861

1

285961fc

20Mbps RS485 Transceivers

with Integrated Switchable

Termination

RS485/422 transceivers operating on 5V supplies. The

receiver includes a logic-selectable 120Ω termination,

one-eighth unit load supporting up to 256 nodes per bus

(C-, I-grades), and a failsafe feature that guarantees a high

outputstateunderconditionsoffloatingorshortedinputs.

The driver features a logic-selectable low-EMI 250kbps

operating mode, and 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.

EnhancedESDprotectionallowstheLTC2859andLTC2861

towithstand±15kV(humanbodymodel)onthetransceiver

interface pins without latchup or damage.

n

Low Power RS485/RS422 Transceiver

n

Level Translator

n

Backplane Transceiver

n

Integrated, Logic-Selectable 120Ω Termination

Resistor

n

20Mbps Max Data Rate

n

No Damage or Latchup to ESD: ±15kV HBM

n

High Input Impedance Supports 256 Nodes

(C-, I-Grades)

n

Operation Up to 105°C (LTC2859H)

n

250kbps Low-EMI Mode

n

Guaranteed Failsafe Receiver Operation Over the

Entire Common Mode Range

n

Current Limited Drivers and Thermal Shutdown

n

Delayed Micropower Shutdown (5µA Max)

n

Power Up/Down Glitch-Free Driver Outputs

n

Low Operating Current (900µA Max in Receive Mode)

n

Meets All TIA/EIA-485-A Specifications

n

Available in 10-Pin 3mm

× 3mm DFN, 12-Pin

4mm

× 3mm DFN and 16-Pin SSOP Packages

LTC2859 at 20Mbps

PART NUMBER

DUPLEX

PACKAGE

LTC2859

Half

DFN-10

LTC2861

Full

SSOP-16, DFN-12

Typical applicaTion

FeaTures

applicaTions

DescripTion

proDucT selecTion GuiDe

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.

285961 TA02

20ns/DIV

2V/DIV

DI

Y–Z

Y

Z

RE

TE

RO

DE

DI

SLO

R

D

2859/61 TA01

LTC2859

120Ω

RE

RO

TE

DE

DI

SLO

R

D

LTC2859

120Ω

RE

RO

TE DE

DI SLO

R

D

LTC2859

120Ω