________________General Description

The MAX3233E/MAX3235E are EIA/TIA-232 and V.28/V.24

communications interfaces with automatic shutdown/

wake-up features, high data-rate capabilities, and

enhanced electrostatic discharge (ESD) protection. All

transmitter outputs and receiver inputs are protected to

±15kV using IEC 1000-4-2 Air-Gap Discharge, to ±8kV

using IEC 1000-4-2 Contact Discharge, and to ±15kV

using the Human Body Model. The MAX3233E operates

from a +3.3V supply; the MAX3235E operates from +5.0V.

All devices achieve a 1µA supply current using Maxim’s

revolutionary AutoShutdown Plus™ feature. These

devices automatically enter a low-power shutdown

mode when the following two conditions occur: either

the RS-232 cable is disconnected or the transmitters of

the connected peripherals are inactive, and the UART

driving the transmitter inputs is inactive for more than

30 seconds. They turn on again when they sense a

valid transition at any transmitter or receiver input.

AutoShutdown Plus saves power without changes to

the existing BIOS or operating system.

The MAX3233E/MAX3235E have internal dual charge

pumps requiring no external capacitors. Both trans-

ceivers have a proprietary low-dropout transmitter out-

put stage that enables true RS-232 performance from a

+3.0V to +3.6V supply for the MAX3233E or a +4.5V to

+5.5V supply for the MAX3235E. These devices are

guaranteed to operate up to 250kbps. Both are avail-

able in space-saving 20-pin wide SO or plastic DIP

packages.

________________________Applications

Subnotebook and Palmtop Computers

Cellular Phones

Battery-Powered Equipment

Handheld Equipment

Peripherals

Embedded Systems

____________________________Features

♦ 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

♦ Latchup Free

♦ 1µA Supply Current

♦ AutoShutdown Plus—1997 EDN Magazine

Innovation of the Year

♦ Single-Supply Operation

+3.0V to +3.6V (MAX3233E)

+4.5V to +5.5V (MAX3235E)

♦ 250kbps Guaranteed Data Rate

♦ 6V/µs Guaranteed Slew Rate

♦ Meets EIA/TIA-232 Specifications Down to 3.0V

(MAX3233E)

♦ Internal Charge-Pump Capacitors

±15kV ESD-Protected, 1µA, 250kbps, 3.3V/5V, Dual

RS-232 Transceivers with Internal Capacitors

________________________________________________________________ Maxim Integrated Products

1

19-1473; Rev 2; 8/04

PART

MAX3233ECWP

0°C to +70°C

TEMP RANGE

PIN-PACKAGE

20 SO

AutoShutdown Plus is a trademark of Maxim Integrated Products, Inc.

_______________Ordering Information

Ordering Information continued at end of data sheet.

MAX3233E

MAX3235E

12

13

14

15

16

17

18

4

1

R2OUT

R2IN

T2OUT

GND

V-

C2-

C2+

C1-

C1+

V+

V+

INVALID

T2IN

T1IN

FORCEON

R1OUT

T1OUT

R1IN

FORCEOFF

2

9

10

5

6

7

8

3

19

20

11

CHARGE

PUMP

SO/DIP

Pin Configuration/

Functional Diagram

Typical Operating Circuit appears at end of data sheet.

MAX3233ECPP

0°C to +70°C

20 Plastic DIP

MAX3233EEPP

-40°C to +85°C

20 Plastic DIP

MAX3233EEWP

-40°C to +85°C

20 SO

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.