General Description

The MAX3322E/MAX3323E 3.0V to 5.5V powered

EIA/TIA-232 and V.28/V.24 communications interfaces

are designed for multidrop applications with low power

requirements, high data-rate capabilities, and

enhanced electrostatic discharge (ESD) protection. All

RS-232 inputs and outputs are protected to ±15kV

using the IEC 1000-4-2 Air-Gap Discharge method,

±8kV using the IEC 1000-4-2 Contact Discharge

method, and ±15kV using the Human Body Model.

The MAX3322E/MAX3323E have pin-selectable

5k

Ω/high-impedance RS-232 receivers. These devices

are capable of receiving data in high-impedance mode.

In multidrop applications, one receiver has a 5k

Ω input

resistance, while the other receivers are high imped-

ance to ensure the RS-232 standard is observed. Logic

control permits selection of the functional mode: high

impedance or RS-232 standard load. The transmitters

are enabled by logic control to allow the multiplexing of

the inputs to a single UART.

A proprietary low-dropout transmitter output stage

enables true RS-232 performance from a 3.0V to 5.5V

supply with a dual charge pump. The charge pump

requires only four small 0.1µF capacitors for operation

from a 3.3V supply. The MAX3322E/MAX3323E are

capable of running at data rates up to 250kbps while

maintaining RS-232-compliant output levels. The

operation in mixed-logic voltage systems. Both input

and output logic levels are pin programmable through

The MAX3322E is a 2Tx/2Rx device for hardware hand-

shaking in standard RS-232 mode, and the MAX3323E

is a 1Tx/1Rx, required in most multidrop applications.

The MAX3322E is offered in a space-saving TSSOP

package. The MAX3323E is offered in 16-pin DIP and

space-saving TSSOP packages.

Applications

Bar-Code Scanners

Video Security

Industrial Data Acquisition

Data Splitters

Features

o Pin-Selectable 5kΩ/High-Impedance Receivers

o Transmitter Outputs Three-Stated by Logic

Control

Systems

o 1Tx/1Rx (MAX3323E) or 2Tx/2Rx (MAX3322E)

Versions

o 250kbps Data Rate

o 1µA Low-Power Shutdown

o High ESD Protection for RS-232 I/O Pins

±15kV—Human Body Model

±8kV—IEC 1000-4-2 Contact Discharge

±15kV—IEC 1000-4-2 Air-Gap Discharge

±15kV ESD-Protected, RS-232 Transceivers for

Multidrop Applications

________________________________________________________________ Maxim Integrated Products

1

20

19

18

17

16

15

14

13

1

2

3

4

5

6

7

8

GND

SHDN

C2+

C1-

V+

C1+

TOP VIEW

RENABLE

TXENABLE

TIN2

ROUT2

RIN2

TOUT2

V-

C2-

12

11

9

10

TIN1

ROUT1

RIN1

TOUT1

MAX3322E

TSSOP

Pin Configurations

Ordering Information

19-2667; Rev 1; 1/03

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

PART

TEMP RANGE

PIN-PACKAGE

MAX3322E EUP

-40

°C to +85°C

20 TSSOP

MAX3323E EUE

-40

°C to +85°C

16 TSSOP

MAX3323EEPE

-40

°C to +85°C

16 DIP

Pin Configurations continued at end of data sheet.

Typical Operating Circuit and Functional Diagram appear

at end of data sheet.