LTC1337
5V Low Power RS232
3-Driver/5-Receiver Transceiver
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FEATURES
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DESCRIPTIO
Low Supply Current: 300µA
ESD Protection: Over ±10kV
1µA Supply Current in Shutdown
Operates from a Single 5V Supply
Uses Small Capacitors: 0.1µF
Operates to 120k Baud
Three-State Outputs Are High Impedance When Off
Output Overvoltage Does Not Force Current Back into
Supplies
RS232 I/O Lines Can Be Forced to ±25V without
Damage
Pin Compatible with LT ®1137A and LT1237
Flowthrough Architecture
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APPLICATIO S
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In Shutdown mode, the supply current is further reduced
to 1µA. All RS232 outputs assume a high impedance state
in Shutdown and with the power off.
The LTC1337 is fully compliant with all data rate and
overvoltage RS232 specifications. The transceiver can
operate up to 120k baud with a 1000pF// 3kΩ load. Both
driver outputs and receiver inputs can be forced to ±25V
without damage, and can survive multiple ±10kV ESD
strikes.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Notebook Computers
Palmtop Computers
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The LTC®1337 is a 3-driver/5-receiver RS232 transceiver
with very low supply current. In the no load condition, the
supply current is only 300µA. The charge pump only
requires four 0.1µF capacitors and can supply up to 12mA
of extra current to power external circuitry.
TYPICAL APPLICATIO
3-Drivers/5-Receivers with Shutdown
VCC
C2
0.1µF
DRIVER 1 OUT
RX1 IN
DRIVER 2 OUT
RX2 IN
RX3 IN
RX4 IN
DRIVER 3 OUT
RX5 IN
ON/OFF
2
28
LTC1337
V–
27
3
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
18
12
17
13
16
14
C3
0.1µF
C4
0.1µF
15
DRIVER 1 IN
RX1 OUT
DRIVER 2 IN
RX2 OUT
RX3 OUT
RX4 OUT
DRIVER 3 IN
1.2
500
1.0
400
GND
0.6
300
0.4
200
SHUTDOWN
CURRENT
100
0
RX5 OUT
0.8
QUIESCENT
CURRENT
–20
0
20
40
60
TEMPERATURE (°C)
SHUTDOWN CURRENT (µA)
C1
0.1µF
1
QUIESCENT CURRENT OPERATING (µA)
V+
Supply Current
600
0.2
80
0
TEST CONDITION:
VCC = 5V, ALL DRIVER INPUTS TIED TO VCC
1337 TA01
1337 TA02
1337fa
1
