LT1180A/LT1181A
Low Power 5V RS232
Dual Driver/Receiver with
0.1µF Capacitors
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DESCRIPTIO
FEATURES
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ESD Protection over ±10kV
Uses Small Capacitors: 0.1µF
120kBaud Operation for RL = 3k, CL = 2500pF
250kBaud Operation for RL = 3k, CL = 1000pF
Outputs Withstand ±30V Without Damage
CMOS Comparable Low Power: 40mW
Operates from a Single 5V Supply
Rugged Bipolar Design
Outputs Assume a High Impedance State When Off
or Powered Down
Meets All RS232 Specifications
Available With or Without Shutdown
Absolutely No Latch-up
Available in SO Package
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APPLICATIO S
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Portable Computers
Battery-Powered Systems
Power Supply Generator
Terminals
Modems
The LT1181A is available in 16-pin DIP and SO packages.
The LT1180A is supplied in 18-pin DIP and SO packages
for applications which require shutdown.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TransZorb is a registered trademark of General Instruments, GSI
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The LT®1180A/LT1181A are dual RS232 driver/receiver
pairs with integral charge pump to generate RS232 voltage levels from a single 5V supply. These circuits feature
rugged bipolar design to provide operating fault tolerance
and ESD protection unmatched by competing CMOS
designs. Using only 0.1µF external capacitors, these circuits consume only 40mW of power, and can operate to
120k baud even while driving heavy capacitive loads. New
ESD structures on the chip allow the LT1180A/LT1181A to
survive multiple ±10kV strikes, eliminating the need for
costly TransZorbs® on the RS232 line pins. The LT1180A/
LT1181A are fully compliant with EIA RS232 standards.
Driver outputs are protected from overload, and can be
shorted to ground or up to ±30V without damage. During
shutdown or power-off conditions, driver and receiver
outputs are in a high impedance state, allowing line
sharing.
TYPICAL APPLICATIO
0.1µF
2
17
4
+
3
V + OUT
+
0.1µF
LT1180A
5
7
6
12
15
11
8
13
LOGIC
INPUTS
14
RS232 OUTPUT
RS232 OUTPUT
RS232 INPUT
RECEIVER
OUTPUT
R
CL = 50pF
INPUT
5k
LOGIC
OUTPUTS
10
ON/OFF
V – OUT
0.1µF
DRIVER
OUTPUT
RL = 3k
CL = 2500pF
+
+
0.1µF
Output Waveforms
5V INPUT
18
9
5k
RS232 INPUT
LT1180A • TA02
16
LT1180A • TA01
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