SN75LBC776 Datasheet, PDF (1/14 Pages) Texas Instruments – SINGLE-CHIP GeoPortE TRANSCEIVER

SN75LBC776
SINGLE-CHIP GeoPort™ TRANSCEIVER
D Single-Chip Interface Solution for the
9-terminal GeoPort™ Host (DTE)
D Designed to Operate up to 4 Mbit/s Full
Duplex
D Single 5-V Supply Operation
D 6-kV ESD Protection on All Terminals
D Backward compatible With AppleTalk™ and
LocalTalk™
D Combines Multiple Components into a
Single-chip Solution
D Complements the SN75LBC777 9-Terminal
GeoPort Peripheral (DCE) Interface Device
D LinBiCMOS™ Process Technology
SLLS221A – NOVEMBER 1995 – REVISED JANUARY 1996
DW PACKAGE
(TOP VIEW)
DA1
1
V_EE
2
C–
3
C+
4
SHDN
5
DZ2
6
DY2
7
GND
8
DEN
9
DA2
10
20
GND
19
V_CC
18
DY1
17
RY3
16
RB3
15
RA2
14
RY2
13
RB1
12
RA1
11
RY1
description
The SN75LBC776 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 megabits per second (Mbit/s) full duplex. GeoPort is a serial communications standard
that is intended to replace the RS-232, Appletalk, and LocalTalk printer ports all in one connector in addition
to providing real-time data transfer capability. It provides point-to-point connections between
GeoPort-compatible devices with data transmission rates up to 4 Mbit/s full duplex and a hot-plug feature.
Applications include connection to telephony, integrated services digital network (ISDN), digital sound and
imaging, fax-data modems, and other serial and parallel connections. The GeoPort is backwardly compatible
to both LocalTalk and AppleTalk.
While the SN75LBC776 is powered-off (V_CC = 0) the outputs are in a high-impedance state. When the shutdown
(SHDN) terminal is high, the charge pump is powered down and the outputs are in a high-impedance state. The
driver enable (DEN) terminal sends the outputs of the differential driver into a high-impedance state with a high
input signal. All drivers and receivers have fail-safe mechanisms to ensure a high output state when the inputs
are left open.
A switched-capacitor voltage converter generates the negative voltage required from a single 5-V supply using
four 0.1-µF capacitors, two capacitors between the C+ and C- terminals and two capacitors between V_EE and
ground.
The SN75LBC776 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.
GeoPort, LocalTalk, and AppleTalk are trademarks of Apple Computer, Incorporated.
LinBiCMOS is a trademark of Texas Instruments Incorporated.
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.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright © 1996, Texas Instruments Incorporated
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