LTC1320_15 Datasheet, PDF (1/8 Pages) Linear Technology – AppleTalk Transceiver

OBSOLETE:
FOR INFORMATION PURPOSES ONLY
Contact Linear Technology for Potential Replacement
FEATURES
I _{Single Chip Provides Complete}
LocalTalk^©/AppleTalk^© Port
I _{Low Power: ICC = 1.2mA Typ}
I _{Shutdown Pin Reduces ICC to 30µA Typ}
I _{Drivers Maintain High Impedance in Three-State}
or with Power Off
I _{30ns Driver Propagation Delay Typ}
I _{5ns Driver Skew Typ}
I _{Thermal Shutdown Protection}
I _{Drivers are Short-Circuit Protected}
APPLICATI S
I _{LocalTalk Peripherals}
I _{Notebook/Palmtop Computers}
I _{Battery-Powered Systems}
AppleTalk and LocalTalk are registered trademarks of Apple Computer, Inc.
LTC1320
AppleTalk^© Transceiver
DESCRIPTIO
The LTC1320 is an RS422/RS562 line transceiver de-
signed to operate on LocalTalk networks. It provides one
differential RS422 driver, one single-ended RS562 driver,
two single-ended RS562 receivers, and one differential
RS422 receiver. The LTC1320 draws only 1.2mA quies-
cent current when active and 30µA in shutdown, making
it ideal for use in battery-powered devices and other
systems where power consumption is a primary concern.
The LTC1320 drivers are specified to drive ±2V into 100Ω.
Additionally, the driver outputs three-state when disabled,
during shutdown, or when the power is off; they maintain
high impedance even with output common-mode volt-
ages beyond the power supply rails. Both the driver
outputs and receiver inputs are protected against ESD
damage to beyond 5kV.
The LTC1320 is available in the 18-pin SOL package.
TYPICAL APPLICATI
Typical LocalTalk Connection
1
DATA IN
3
TX ENABLE
5
RX ENABLE
8
DATA OUT
SHUTDOWN ⁴
5V
18
17 ^22Ω
LTC1320
#1
16 ^22Ω
11 ^22Ω
10 ^22Ω
9
14
–5V
LocalTalk
22Ω TRANSFORMER
100pF
22Ω
120Ω
100pF
22Ω
100pF
22Ω
100pF
1k
1k
LTC1320 • TA01
DATA IN
SIGNALS
ON LINE
DATA OUT
(REMOTE
RECEIVER)
Output Waveforms
50ns/DIV
5V/DIV
2V/DIV
2V/DIV
5V/DIV
1