SN75LBC771

GEOPORT

™ TRANSCEIVER

SLLS226A – APRIL 1996 – REVISED NOVEMBER 1997

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POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

D Supports a 9-Pin GeoPort™ Host Interface

Standard for the Intelligent Network Port

D Designed to Operate up to 4-Mbit/s Full

Duplex

D ±5 V Supply Operation

D Provides 6 kV ESD Protection

D Has Driver Short-Circuit Protection

D Includes Failsafe Mechanism for Open

Inputs

D Is Backward Compatible with AppleTalk™

and LocalTalk

™

D Combines Multiple Components into a

Single Chip Solution

D Complements the SN75LBC772 9-Pin

GeoPort Peripheral (DCE) Interface Device

D Uses LinBiCMOS™ Process Technology

description

The SN75LBC771 is a low-power LinBiCMOS

™

device that incorporates the drivers and receivers

for a 9-pin GeoPort host interface. GeoPort

combines

hybrid

EIA/TIA-422-B

and

EIA/

TIA-423-B drivers and receivers to transmit data

up to four-Mbit/s full duplex. GeoPort is a serial

communications standard that is intended to

replace the RS-232, AppleTalk, and printer ports

all in one connector in addition to providing

real-time

data

transfer

capability.

The

SN75LBC771 provides point-to-point connec-

tions between GeoPort-compatible devices with

data transmission rates up to 4-Mbit/s full duplex

featuring a hot-plug capability. Applications

include connection to telephone, ISDN, digital

sound and imaging, fax-data modems, and other

traditional serial and parallel connections. The

GeoPort is backwardly compatible to both

LocalTalk and AppleTalk.

While the SN75LBC771 is powered off (VCC and VEE = 0), the outputs are in a high-impedance state. Also, when

the shutdown (SHDN) terminal is high, all outputs go into a high-impedance state. A logic high on the driver

enable (DEN) terminal places the outputs of the differential driver into a high-impedance state. All drivers and

receivers have fail-safe mechanisms that ensure a high output state when the inputs are left open.

The SN75LBC771 is characterized for operation over the 0

°C to 70°C temperature range.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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DA1

VEE

NC

NC

SHDN

DZ2

DY2

GND

DEN

DA2

GND

VCC

DY1

RY3

RB3

RA2

RY2

RB1

RA1

RY1

DW PACKAGE

(TOP VIEW)

DY2

DZ2

RY1

DY1

RY2

RY3

DA2

DEN

RB1

RA1

DA1

RA2

RB3

SHDN

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logic diagram (positive logic)

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Copyright

© 1997, Texas Instruments Incorporated

GeoPort, LocalTalk, and AppleTalk are trademarks of Apple Computer, Incorporated.

LinBICMOS is a trademark of Texas Instruments Incorporated.