_______________General Description

The MAX3221/MAX3223/MAX3243 achieve 1µA supply

current with Maxim’s revolutionary AutoShutdown™ fea-

ture. When the MAX3221/MAX3223/MAX3243 do not

sense a valid signal level on their receiver inputs, the

on-board power supply and drivers shut down. This

occurs if the RS-232 cable is disconnected or if the

transmitters of the connected peripheral are turned off.

The system turns on again when a valid level is applied

to any RS-232 receiver input. As a result, the system

saves power without changes to the existing BIOS or

operating system.

The MAX3221/MAX3223/MAX3243 transceivers are 3V-

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

interfaces intended for notebook computer applica-

tions. A proprietary, high-efficiency, dual charge-pump

power supply and a low-dropout transmitter combine to

deliver true RS-232 performance from a single +3.0V to

+5.5V supply. A guaranteed data rate of 120kbps pro-

vides compatibility with popular software for communi-

cating with personal computers.

The MAX3221/MAX3223/MAX3243 require only 0.1µF

capacitors in 3.3V operation, and can operate from input

voltages ranging from +3.0V to +5.5V. They are ideal for

3.3V-only systems, mixed 3.3V and 5.0V systems, or

5.0V-only systems that require true RS-232 performance.

The MAX3221 is a 1-driver/1-receiver 16-pin SSOP ver-

sion of the 20-pin MAX3223 (2-driver/2-receiver). The

MAX3243 3-driver/5-receiver, complete serial port is

ideal for notebook or subnotebook computers. The

MAX3243 includes one complementary always-active

receiver. This receiver can monitor an external device

(such as a modem) in shutdown, without forward bias-

completely removed.

____________________________Features

o 1µA Supply Current Achieved with AutoShutdown

o Small 0.1µF Capacitors

o Meets EIA/TIA-562 Specifications Down to 2.7V

o Guaranteed 120kbps Data Rate

o 6V/µs Min Guaranteed Slew Rate

o Smallest Single-Supply RS-232 Transceiver

(MAX3221)

o Guaranteed Mouse Driveability (MAX3243)

o Small TSSOP Package (MAX3223/MAX3243)

________________________Applications

Notebook, Subnotebook, and Palmtop Computers

Battery-Powered Equipment

Hand-Held Equipment

Peripherals

Printers

1µA Supply-Current, True +3V to +5.5V

RS-232 Transceivers with AutoShutdown

________________________________________________________________ Maxim Integrated Products

1

19-0306; Rev 6; 3/99

PART

MAX3221CAE

MAX3221EUE†

-40°C to +85°C

0°C to +70°C

TEMP. RANGE

PIN-PACKAGE

16 SSOP

16 TSSOP

* Covered by U.S. Patent numbers 4,636,930; 4,679,134; 4,777,577; 4,797,899; 4,809,152; 4,897,774; 4,999,761; and other patents pending.

†Future product—contact factory for availability.

AutoShutdown is a trademark of Maxim Integrated Products.

Pin Configurations appear at end of data sheet.

Typical Operating Circuits appear at end of data sheet.

MAX3223EPP

-40°C to +85°C

20 Plastic DIP

MAX3223EAP

-40°C to +85°C

20 SSOP

MAX3243CWI

0°C to +70°C

28 Wide SO

MAX3243CAI

0°C to +70°C

28 SSOP

MAX3243EWI

-40°C to +85°C

28 Wide SO

MAX3243EAI

-40°C to +85°C

28 SSOP

MAX3223CPP

MAX3223CAP

0°C to +70°C

0°C to +70°C

20 Plastic DIP

20 SSOP

______________Ordering Information

_____________________Selector Guide

MAX3221

MAX3223

MAX3243

1

2

3

1

2

3.0 to 5.5

3.0 to 5.5

3.0 to 5.5

5

Yes

Yes

Yes

PART

Tx

Rx

MAX3221CUE†

0°C to +70°C

16 TSSOP

MAX3221EAE

-40°C to +85°C

16 SSOP

MAX3223CUP

0°C to +70°C

20 TSSOP

MAX3223EUP

-40°C to +85°C

20 TSSOP

MAX3243CUI

0°C to +70°C

28 TSSOP

MAX3243EUI

-40°C to +85°C

28 TSSOP

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.

For small orders, phone 1-800-835-8769.