1

LT1080/LT1081

Advanced Low Power

5V RS232 Dual Driver/Receiver

The LT

receiver with charge pump to guarantee absolutely no

latchup. These interface optimized devices provide a real-

istic balance between CMOS levels of power dissipation

and real world requirements for ruggedness. The driver

outputs are fully protected against overload and can be

shorted to

±30V. Unlike CMOS, the advanced architecture

of the LT1080/LT1081 does not load the signal line when

“shut down” or when power is off. Both the receiver and

RS232 outputs are put into a high impedance state. An

advanced output stage allows driving higher capacitive

loads at higher speeds with exceptional ruggedness

against ESD.

For applications requiring up to five drivers and five

receivers with charge pump in one package see the LT1130A

Series data sheet. A version of the LT1080/LT1081, the

LT1180A and LT1181A that use only 0.1

µF capacitors, is

also available. All of Linear Technology’s RS232 ICs are

available in standard surface mount packages.

s

Superior to CMOS

– Improved Speed: Operates over 120kBaud

– Improved Protection: Outputs Can Be Forced

to

±30V without Damage

– Three-State Outputs Are High

Impedance When Off

– Only Needs 1

µF Capacitors

s

Absolutely No Latchup

s

CMOS Comparable Low Power: 60mW

s

Can Power Additional RS232 Drivers: 10mA

s

Supply Current in Shutdown: 1

µA

s

Available in SO Package

s

Available with or without Shutdown

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

s

Portable Computers

s

Battery-Powered RS232 Systems

s

Power Supply Generator

s

Terminals

s

Modems

Supply Generator Outputs

OUTPUT CURRENT (mA)

02468

10 12 14 16 18 20

1080/81 TA01a

10

8

6

4

2

0

–2

–4

–6

–8

–10

–

+

LOGIC

INPUTS

LOGIC

OUTPUTS

ON/OFF

18

10

13

11

12

6

5

4

2

16

9

14

8

15

7

3

17

5V INPUT

9V OUTPUT

–9V OUTPUT

RS232 OUTPUT

RS232 OUTPUT

RS232 INPUT

RS232 INPUT

1080/81 • TA01

5k

5k

LT1080

1

µF

1

µF

1

µF

1

µF

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO