SN75LBC775 Datasheet, PDF (1/11 Pages) Texas Instruments – SINGLE-CHIP APPLETALKE AND LOCALTALKE TRANSCEIVER

SN75LBC775
SINGLE-CHIP APPLETALK™ AND LOCALTALK™ TRANSCEIVER
D Single-Chip Interface Solution for
AppleTalk™ and LocalTalk™
D Designed to Operate Up To 1 Mbps In
AppleTalk and LocalTalk
D Switched-Capacitor Voltage Converter
Allows for Single 5-V Operation
D 4-kV ESD Protection on Bus Terminals
D Combines Multiple Components into a
Single Chip Solution
D LinBiCMOS™ Process Technology
description
The SN75LBC775 is a low-power LinBiCMOS™
device that incorporates the drivers and receivers
for an AppleTalk or a LocalTalk interface and a
switched-capacitor voltage converter for a single
5-V supply operation. LocalTalk uses a hybrid of
RS-422 with the transceiver connected to the
network through a small isolation transformer.
The AppleTalk mode provides point-to-point
communications and uses the same differential
driver and receiver as LocalTalk with the addition
of a hybrid RS-423, single-ended handshake
driver (HSK) and receiver. In the AppleTalk mode,
the port connects directly to the receiver with no
isolation transformer.
While the device power is turned off (V_CC = 0) or
disabled in the LocalTalk mode, the outputs are in
a high-impedance state. When the driver enable
(DEN) terminal is high, both the differential and
serial driver outputs are in a high-impedance
state.
The receiver output can be disabled and becomes
a high impedance when the REN terminal is low.
A switched-capacitor voltage converter generates
the negative voltage required from a single 5-V
supply using two 22-µF capacitors. One capacitor
is between the C + and C – terminals and the
second is between V_SS and ground.
The SN75LBC775 is characterized for operating
over the temperature range of 0°C to 70°C.
SLLS216A – MAY 1995 – REVISED JANUARY 1996
DW PACKAGE
(TOP VIEW)
HSKA ¹
V_SS
2
C– ³
C+ 4
DEN 5
DY 6
DZ 7
GND 8
V_CC
9
DA 10
20 _GND
19
V_CC
18 _HSKY
17 RY2
16 RA2
15 RB2
14 RB1
13 RA1
12 RY1
11 REN
functional diagram
1
HSKA
18 _HSKY
DA ¹⁰
6 _DY
7
DZ
DEN ⁵
RY1 ¹²
RY2 ¹⁷
13 _RA1
14 _RB1
16 _RA2
15 _RB2
REN ¹¹
VCC ¹⁹
8
GND
Charge Pump
2 VSS
–5 V
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.
LocalTalk and AppleTalk are trademarks of Apple Computer, Inc.
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.
Copyright © 1996, Texas Instruments Incorporated
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
• POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
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