LT1330
5V RS232 Transceiver with
3V Logic Interface and One
Receiver Active in SHUTDOWN
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DESCRIPTIO
FEATURES
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3V Logic Interface
ESD Protection over ±10kV
Uses Small Capacitors: 0.1µF, 0.2µF, 1.0µF
One Low Power Receiver Remains Active While in
SHUTDOWN
Pin Compatible with LT1137A and LT1237
120kBaud Operation for RL = 3k, CL = 2500pF
250kBaud Operation for RL = 3k, CL = 1000pF
CMOS Comparable Low Power: 30mW
Easy PC Layout – Flowthrough Architecture
Rugged Bipolar Design
Outputs Assume a High Impedance State When Off
or Powered Down
Absolutely No Latchup
60µA Supply Current in SHUTDOWN
Available in SO and SSOP Packages
The LT1330 is a three driver, five receiver RS232 transceiver with low supply current. Designed to interface with
new 3V logic, the LT1330 operates with both a 5V power
supply and a 3V logic power supply. The chip may be shut
down to micropower operation with one receiver remaining active to monitor RS232 inputs such as ring detect
from a modem.
The LT1330 is fully compliant with all EIA RS232 specifications. Additionally, the RS232 line input and output pins
are resilient to multiple ±10kV ESD strikes. This eliminates
the need for costly TransZorbs® on line pins for the RS232
part.
The LT1330 operates to 120k baud even driving high
capacitive loads. During SHUTDOWN, driver and receiver
outputs are at a high impedance state allowing devices to
be paralleled.
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APPLICATI
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Notebook Computers
Palmtop Computers
TransZorb is a registered trademark of General Instruments, GSI
UO
TYPICAL APPLICATI
Output Waveforms
5V VCC
2 × 0.1µF
RX1 IN
RX2 IN
RX3 IN
RX4 IN
DRIVER 3 OUT
RX5 IN (LOW-Q)
ON/OFF
3V VL
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4
DRIVER 2 OUT
V–
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3
+
DRIVER 1 OUT
TO
LINE
2
28
LT1330
25
5
24
6
23
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8
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+
1.0µF
1
2 × 0.1µF
+
V+
RECEIVER
OUTPUT
VL = 3V
CL = 50pF
0.1µF
DRIVER 1 IN
DRIVER
OUTPUT
RL = 3k
CL = 2500pF
RX1 OUT
DRIVER 2 IN
RX2 OUT
TO LOGIC
R
RX3 OUT
RX4 OUT
DRIVER 3 IN
RX5 OUT (LOW-Q)
GND
DRIVER
DISABLE
INPUT
RING DETECT IN
µCONTROLLER OR
µPROCESSOR
1330 TA02
SHUTDOWN
CONTROL OUT
1330 TA01
1
