LT1341
5V RS232 Transceiver with One
Receiver Active in Shutdown
FEATURES
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DESCRIPTIO
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One Receiver Remains Active While in Shutdown
ESD Protection Over
鹵10kV
Uses Small Capacitors: 0.1碌F, 0.2碌F
60碌A Supply Current in Shutdown
Pin Compatible with LT1137A
120kBaud Operation for R
L
= 3k, C
L
= 2500pF
250kBaud Operation for R
L
= 3k, C
L
= 1000pF
CMOS Comparable Low Power: 60mW
Operates from a Single 5V Supply
Easy PC Layout: Flowthrough Architecture
Rugged Bipolar Design
Outputs Assume a High Impedance State When
Off or Powered Down
Absolutely No Latchup
Available in SSOP Package
The LT
廬
1341 is an advanced low power three-driver, five-
receiver RS232 transceiver. Included on the chip is a
shutdown pin for reducing supply current to near zero.
During shutdown one receiver remains active to detect
incoming RS232 signals, for example, to wake up a
system. All other receivers and the drivers assume high
impedance states during shutdown.
The driver disable function provides additional control of
operating mode. When driver disable is high the charge
pump and drivers turn off. Receivers continue to operate
during driver disable.
New ESD structures on the chip allow the LT1341 to
survive multiple
鹵10kV
strikes, eliminating the need for
costly TransZorbs
廬
on the RS232 line pins.
The LT1341 is fully compliant with all EIA RS232 specifi-
cations and operates in excess of 120kbaud even driving
heavy capacitive loads.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TransZorb is a registered trademark of General Instruments, GSI
APPLICATI
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Notebook Computers
Palmtop Computers
TYPICAL APPLICATI
V
+
0.1碌F
2
脳
0.1碌F
DRIVER 1 OUT
RX1 IN
DRIVER 2 OUT
TO LINE
RX2 IN
RX3 IN
RX4 IN
DRIVER 3 OUT
RX5 IN (LOW-Q)
ON/OFF
NC
V
CC
1
2
3
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5
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8
9
10
11
12
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14
LT1341
28 V
鈥?/div>
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24
23
22
21
20
19
DRIVER 1 IN
RX1 OUT
DRIVER 2 IN
RX2 OUT
RX3 OUT
RX4 OUT
TO LOGIC
2
脳
0.1碌F
0.1碌F
RECEIVER
OUTPUT
C
L
= 50pF
DRIVER
R
OUTPUT
R
L
= 3k
C
L
= 2500pF
DRIVER 3 IN
18 RX5 OUT (LOW-Q)
17
GND
16
DRIVER DISABLE
15
NC
INPUT
RING DETECT IN
碌CONTROLLER
OR
碌PROCESSOR
SHUTDOWN
CONTROL OUT
LT1341 鈥?TA01
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Output Waveforms
LT1341 鈥?TA02
UO
UO
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