LTC1323
Single 5V
AppleTalk
廬
Transceiver
FEATURES
s
s
s
DESCRIPTIO
s
s
s
s
s
s
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Single Chip Provides Complete
LocalTalk
廬
/AppleTalk Port
Operates From a Single 5V Supply
ESD Protection to
鹵10kV
on Receiver Inputs
and Driver Outputs
Low Power: I
CC
= 2.4mA Typ
Shutdown Pin Reduces I
CC
to 0.5碌A Typ
Receiver Keep-Alive Function: I
CC
= 65碌A Typ
Differential Driver Drives Either Differential
AppleTalk or Single-Ended EIA562 Loads
Drivers Maintain High Impedance in Three-State or
with Power Off
Thermal Shutdown Protection
Drivers are Short-Circuit Protected
APPLICATI
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S
The LTC
廬
1323 is a multi-protocol line transceiver designed
to operate on AppleTalk or EIA562-compatible single-
ended networks while operating from a single 5V supply.
There are two versions of the LTC1323 available: a 16-pin
version designed to connect to an AppleTalk network,
and a 24-pin version which also includes the additional
single-ended drivers and receivers necessary to create
an Apple-compatible serial port. An on-board charge
pump generates a 鈥?5V supply which can be used to
power external devices. Additionally, the 24-pin LTC1323
features a micropower keep-alive mode during which
one of the single-ended receivers is kept active to monitor
external wake-up signals. The LTC1323 draws only 2.4mA
quiescent current when active, 65碌A in receiver keep-
alive mode, and 0.5碌A in shutdown, making it ideal for
use in battery-powered systems.
The differential driver can drive either differential AppleTalk
loads or conventional single-ended loads. The driver
outputs three-state when disabled, during shutdown, in
receiver keep-alive mode, or when the power is off. The
driver outputs will maintain high impedance even with
output common-mode voltages beyond the power supply
rails. Both the driver outputs and receiver inputs are
protected against ESD damage to
鹵10kV.
LocalTalk Peripherals
Notebook/Palmtop Computers
Battery-Powered Systems
, LTC and LT are registered trademarks of Linear Technology Corporation.
AppleTalk and LocalTalk are registered trademarks of Apple Computer, Inc.
TYPICAL APPLICATI
1
0.33碌F
2
CPEN 3
TXD 4
TXI 5
TXDEN 6
SHDN 7
RXEN 8
RXO 9
RXO 10
RXDO 11
12
LTC1323
24
CHARGE PUMP
23
22
21
DX
5V
+
0.33碌F
1碌F
5鈩?TO 10鈩?/div>
EMI FILTER =
1碌F
+
EMI FILTER
20 TXD
鈥?/div>
DX
19
TXD
+
EMI FILTER
EMI FILTER
EMI FILTER
EMI FILTER
8
5
2
7
4
1
6
3
18 TXO
17 RXI
RX
16 RXI
15 RXD
鈥?/div>
RX
EMI FILTER
EMI FILTER
14 RXD
+
RX
13
LTC1323 鈥?TA01
U
5鈩?TO 10鈩?/div>
100pF
UO
UO
1
1
2
3
4
5
6
7
8
9
10
11
12
