LT1039/LT1039-16
RS232 Driver/Receiver
with Shutdown
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FEATURES
DESCRIPTIO
The LT®1039 is a triple RS232 driver/receiver that in-
cludes shutdown. Each receiver will accept up to ±30V
input and can drive either TTL or CMOS logic. The RS232
driversacceptTTLlogicinputsandoutputRS232voltage
levels. The outputs are fully protected against overload
and can be shorted to ground or up to ±30V without
damage to the drivers. Additionally, when the system is
shut down or power is off, the outputs are in a high
impedance state allowing data line sharing. Bipolar cir-
cuitry makes this driver/receiver exceptionally rugged
against overloads or ESD damage.
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Operates from ±5V to ±15V Supplies
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Fully Protected Against Overload
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Outputs Can Be Driven ±30V Without Damage
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Three-State Outputs; Outputs Open When Off
Bipolar Circuit—No Latchup
±30V Input Range
Triple Driver/Receiver
No Supply Current in Shutdown
30kΩ Input Impedance
Meets All RS232 Specifications
16-Pin Version—Pin Compatible with MC145406
Available in SO Package
ABIASpinallowsonereceivertobekeptonwhiletherest
of the part is shut down.
15kV ESD: LT1039A
The LT1039 is also available in the 16-pin version,
without shutdown or BIAS pin functions.
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APPLICATIO S
For applications requiring operation from a single 5V
supply, see the LT1080A/LT1081A, LT1180A/LT1181A
and LT1130A data sheets. For applications requiring
15kV ESD, see the LT1039A.
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RS232 Interface
Terminals
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Modems
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
1
+
18
17
16
Driver Output Swing
12V
BIAS*
5V
V
V
CC
LT1039
30k
+
2
3
V
ON/OFF
LOGIC
RS232 IN
POSITIVE
–0.5
4
5
15
14
RS232 OUT
RS232 IN
LOGIC
LOGIC
1.5
NEGATIVE
30k
30k
1.0
0.5
6
7
13
12
LOGIC
LOGIC
RS232 OUT
RS232 IN
–
V
*BIAS PIN USED
TO KEEP THE
8
9
11
10
RS232 OUT
–12V
LOGIC
0
2
4
6
8
10
–
RECEIVER ON
OUTPUT CURRENT (mA)
V
GND
WHILE IN SHUTDOWN
1039 TA02
1039 TA01
1