_______________General Description

The MAX3218 RS-232 transceiver is intended for bat-

tery-powered EIA/TIA-232E and V.28/V.24 communica-

tions interfaces that need two drivers and two receivers

with minimum power consumption from a single low-

voltage supply. It provides a wide +1.8V to +4.25V

operating voltage range while maintaining true RS-232

and EIA/TIA-562 voltage levels. The MAX3218 runs

from two alkaline, NiCd, or NiMH cells without any form

of voltage regulator. A guaranteed 120kbps data rate

provides compatibility with popular software for com-

municating with personal computers.

Supply current is reduced to 1µA with Maxim’s new

AutoShutdown™ feature. When the MAX3218 does not

sense a valid signal level on the 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 either RS-232 receiver input. As a result, the system

saves power without changes to the existing software.

Additionally, the MAX3218 can be forced into or out of

shutdown, under logic control.

While shut down, all receivers can remain active or can

be disabled under logic control, permitting a system

incorporating the CMOS MAX3218 to monitor external

devices while in low-power shutdown. Three-state dri-

vers are provided on both receiver outputs so that multi-

ple receivers, generally of different interface standards,

can be on the same bus. The MAX3218 is available in

20-pin DIP and SSOP packages.

________________________Applications

Battery-Powered Equipment

Subnotebook Computers

PDAs

Hand-Held Equipment

Peripherals

Cellular Phones

____________________________Features

BETTER THAN BIPOLAR!

o 1µA Supply Current Using AutoShutdown™

o Operates Directly from Two Alkaline,

NiCd or NiMH Cells

o +1.8V to +4.25V Single-Supply Voltage Range

o 120kbps Data Rate Guaranteed

o Low-Cost Surface-Mount Components

o Meets EIA/TIA-232E Specifications

o Three-State Receiver Outputs

o Flow-Through Pinout

o On-Board DC-DC Converters

o 20-Pin SSOP and DIP Packages

______________Ordering Information

† Contact factory for dice specifications.

1µA Supply Current, 1.8V to 4.25V-Powered

RS-232 Transceiver with AutoShutdown™

________________________________________________________________

Maxim Integrated Products

1

Call toll free 1-800-998-8800 for free samples or literature.

PART

MAX3218CPP

MAX3218CAP

0°C to +70°C

0°C to +70°C

TEMP. RANGE

PIN-PACKAGE

20 Plastic DIP

20 SSOP

19-0380; Rev 0; 3/95

MAX3218C/D

MAX3218EPP

-40°C to +85°C

0°C to +70°C

20 Plastic DIP

* Patent Pending

™ AutoShutdown is a trademark of Maxim Integrated Products.

MAX3218EAP

-40°C to +85°C

20 SSOP

20

19

18

17

16

15

14

13

1

2

3

4

5

6

7

8

GND

V+

C1+

GND

FORCEON

FORCEOFF

INVALID

LX

TOP VIEW

C1-

V-

T1OUT

T2OUT

T2IN

T1IN

GND

12

11

9

10

R1IN

R2IN

R2OUT

R1OUT

DIP/SSOP

MAX3218

__________________Pin Configuration