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LT1331

3V RS562 or 5V/3V RS232

Transceiver with One Receiver

Active in Shutdown

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FEATURE

DESCRIPTIO

The LT

designed for 3V and mixed 3V/5V systems. Receivers

The transceiver has two shutdown modes. One mode

disables the drivers and the charge pump, the other shuts

down all circuitry except for one low power receiver which

down while in ring detection mode. While shut down, the

drivers and receivers assume high impedance output

states.

The LT1331 is fully compliant with all EIA-RS232 specifi-

compatible with all known interface circuits. Special bipo-

lar construction techniques protect the drivers and receiv-

ers beyond the fault conditions stipulated for RS232. The

RS232 I/O pins are resilient to multiple

±10kV ESD strikes.

An advanced driver output stage operates up to 120kbaud

while driving heavy capacitive loads.

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RS232 Compatible 3V Operation

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3V Logic Interface

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ESD Protection Over

±10kV

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One Low Power Receiver Remains Active While

in Shutdown

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60

µA Supply Current in Shutdown

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Low Power Driver Disable Mode

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Uses Small Capacitors: 0.1

µF, 0.2µF

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CMOS Comparable Low Power: 60mW

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Easy PC Layout: Flowthrough Architecture

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Rugged Bipolar Design

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Outputs Assume a High Impedance State When

Off or Powered Down

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Notebook Computers

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Palmtop Computers

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APPLICATI

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

R

1331 TA02

RECEIVER

OUTPUT

DRIVER

OUTPUT

INPUT

APPLICATI

TYPICAL

3.3V Operation

1

2

3

4

5

6

7

8

9

10

11

12

13

14

28

27

26

25

24

23

22

21

20

19

18

17

16

15

DRIVER 1 IN

RX1 OUT

DRIVER 2 IN

RX2 OUT

RX3 OUT

RX4 OUT

DRIVER 3 IN

0.1

µF

2

× 0.1µF

2

× 0.1µF

0.1

µF

GND

DRIVER DISABLE

NC

TO LINE

TO LOGIC

1331 TA01

RX5 OUT (LOW-Q)

RING DETECT IN

µCONTROLLER

OR

µPROCESSOR

SHUTDOWN

CONTROL OUT

LT1331

DRIVER 1 OUT

RX1 IN

DRIVER 2 OUT

RX2 IN

RX3 IN

RX4 IN

DRIVER 3 OUT

RX5 IN (LOW-Q)

ON/OFF

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