LTC1323 Datasheet, PDF (1/12 Pages) Linear Technology – Single 5V AppleTalk Transceiver

FEATURES
s _{Single Chip Provides Complete}
LocalTalk^®/AppleTalk Port
s _{Operates From a Single 5V Supply}
s _{ESD Protection to ±10kV on Receiver Inputs}
and Driver Outputs
s _{Low Power: ICC = 2.4mA Typ}
s _{Shutdown Pin Reduces ICC to 0.5µA Typ}
s _{Receiver Keep-Alive Function: ICC = 65µA Typ}
s _{Differential Driver Drives Either Differential}
AppleTalk or Single-Ended EIA562 Loads
s _{Drivers Maintain High Impedance in Three-State or}
with Power Off
s _{Thermal Shutdown Protection}
s _{Drivers are Short-Circuit Protected}
APPLICATI S
s _{LocalTalk Peripherals}
s _{Notebook/Palmtop Computers}
s _{Battery-Powered Systems}
, LTC and LT are registered trademarks of Linear Technology Corporation.
AppleTalk and LocalTalk are registered trademarks of Apple Computer, Inc.
LTC1323
Single 5V
AppleTalk^® Transceiver
DESCRIPTIO
The LTC^®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 – 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, 65µA in receiver keep-
alive mode, and 0.5µA 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 ±10kV.
TYPICAL APPLICATI
1
0.33µF
2
CPEN 3
TXD 4
TXI 5
TXDEN 6
SHDN 7
RXEN 8
RXO 9
RXO 10
RXDO 11
12
LTC1323
CHARGE PUMP
DX
DX
RX
RX
RX
5V
1µF
24
23
22
0.33µF
1µF
21
+
20 TXD^–
19 TXD⁺
18 TXO
17 RXI
16 RXI
15 RXD^–
14 RXD⁺
13
EMI FILTER
EMI FILTER
EMI FILTER
EMI FILTER
EMI FILTER
EMI FILTER
5Ω TO 10Ω
EMI FILTER =
5Ω TO 10Ω
100pF
EMI FILTER
876
543
21
LTC1323 • TA01
1