LT1039A/LT1039A-16
Triple RS232 Driver/Receiver
with Shutdown
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DESCRIPTIO
FEATURES
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On-Chip ESD Protection:
±15kV Human Body Model
±15kV IEC-1000-4-2 Air Gap Test**
±8kV IEC-1000-4-2 Contact Test
125kBd Operation with 3kΩ/2500pF Load
250kBd Operation with 3kΩ/1000pF Load
Outputs Can Be Driven ±30V Without Damage
No Supply Current in Shutdown
Operates from ±5V to ±15V Supplies
Fully Protected Against Overload
Three-State Outputs; Outputs Open When Off
Bipolar Circuit—No Latchup
±30V Input Range
Triple Driver/Receiver
30kΩ Input Impedance
Meets All RS232 Specifications
16-Pin Version—Pin Compatible with MC145406
Available in SO Package
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A bias pin allows one receiver to be kept on while the rest
of the part is shut down.
The LT1039A is also available in the 16-pin version,
without shutdown or bias pin functions.
For applications requiring operation from a single 5V
supply, see the LT1180A/LT1181A and LT1130A data
sheets.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
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The LT ®1039A is a triple RS232 driver/receiver that
includes shutdown. Each receiver will accept up to ±30V
input and can drive either TTL or CMOS logic. The RS232
drivers accept TTL logic inputs and output RS232 voltage
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. On-chip ESD
protection eliminates the need for external protection
devices.
RS232 Interface
Terminals
Modems
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TYPICAL APPLICATIO
BIAS*
RS232 IN
1
V+
2
LT1039A
VCC
18
17
16
3
5V
LOGIC
30k
50Ω**
RS232 OUT
RS232 IN
4
15
5
14
LOGIC
LOGIC
30k
*BIAS PIN USED
50Ω**
TO KEEP THE
RS232 OUT
RECEIVER ON
WHILE IN SHUTDOWN
RS232 IN
**50Ω RESISTORS
MAY BE REQUIRED
50Ω**
FOR IEC-1000-4-2
RS232 OUT
ESD PROTECTION
DEPENDING UPON
– 12V
PC BOARD AND
CONNECTOR LEAD LENGTH
6
13
7
12
LOGIC
LOGIC
30k
11
8
9
V–
GND
10
Driver Output Swing
ON/OFF
LOGIC
OUTPUT VOLTAGE REFERRED TO SUPPLIES (V)
12V
V+
– 0.4
– 0.8
–1.2
–1.6
– 2.0
1.2
0.8
0.4
V–
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
OUTPUT CURRENT (mA)
1039A TA01
1039A TA02
1039afa
1