1

LT1381

Low Power 5V RS232 Dual

Driver/Receiver with

0.1

µF Capacitors

R

Output Waveforms

DRIVER

OUTPUT

RECEIVER

OUTPUT

INPUT

S

APPLICATI

s

Portable Computers

s

Battery-Powered Systems

s

Power Supply Generator

s

Terminals

s

Modems

APPLICATI

TYPICAL

DESCRIPTIO

S

FEATURE

s

ESD Protection over

±10kV

s

Low Cost

s

Uses Small Capacitors: 0.1

µF

s

CMOS Comparable Low Power: 40mW

s

Operates from a Single 5V Supply

s

s

s

Rugged Bipolar Design

s

Outputs Assume a High Impedance State When

Powered Down

s

Absolutely No Latchup

s

Available in Narrow SO Package

5k

5k

0.1

µF

LOGIC

INPUTS

LOGIC

OUTPUTS

9

12

10

11

5

4

3

1

15

8

13

7

14

6

2

16

5V INPUT

RS232 OUTPUT

RS232 OUTPUT

RS232 INPUT

RS232 INPUT

LT1381 • TA01

LT1381

0.1

µF

0.1

µF

0.1

µF

+

+

+

S

, LTC and LT are registered trademarks of Linear Technology Corporation.

The LT

integral charge pump to generate RS232 voltage levels

from a single 5V supply. The circuit features rugged

bipolar design to provide operating fault tolerance and

ESD protection unmatched by competing CMOS designs.

Using only 0.1

µF external capacitors, the circuit con-

sumes only 40mW of power and can operate to 120kbaud

even while driving heavy capacitive loads. New ESD struc-

tures on the chip allow the LT1381 to survive multiple

on the RS232 line pins. Driver outputs are protected from

overload and can be shorted to ground or up to

±25V

without damage. During power-off conditions, driver and

receiver outputs are in a high impedance state, allowing

line sharing.

LT1381 • TA02