_______________General Description

The MAX3238 true RS-232 transceiver achieves a

1µA supply current with Maxim’s revolutionary

AutoShutdown Plus™ feature. When the device does

not sense a valid signal transition on either the receiver

or transmitter inputs within 30sec, the on-board power

supply and drivers shut down. This occurs if the RS-232

cable is disconnected or if the transmitters of the con-

nected peripheral are inactive. The system turns on

again when a valid transition is applied to any RS-232

receiver or transmitter input, saving power without

changes to the existing BIOS or operating system.

The MAX3238 5-driver/3-receiver complete serial port is

a 3V-powered EIA/TIA-232 and V.28/V.24 communica-

tions interface intended for notebook or subnotebook

computer applications. 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 250kbps provides compatibility with popu-

lar software for communicating with personal comput-

ers. The MAX3238 requires only 0.1µF capacitors in

3.3V operation. It is ideal for 3.3V-only systems, mixed

3.3V and 5.0V systems, or 5V-only systems that require

true RS-232 performance.

Receiver R1 has an extra, always-active output (in addi-

tion to its standard output), which allows external

devices, such as a modem, to be monitored without for-

ward biasing the protection diodes in circuitry that may

The MAX3238 is available in a space-saving SSOP

package.

________________________Applications

Notebook, Subnotebook, and Palmtop

Computers

High-Speed Modems

Battery-Powered Equipment

Hand-Held Equipment

Peripherals

Printers

AutoShutdown Plus is a trademark of Maxim Integrated Products.

____________________________Features

o 1µA Supply Current Achieved with

AutoShutdown Plus

o Guaranteed Data Rate: 250kbps

o 1µA Low-Power Shutdown

o Receivers Active in AutoShutdown Plus Mode

o Flow-Through Pinout

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

o Guaranteed 6V/µs Slew Rate

+3.0V to +5.5V, 1µA, up to 250kbps, True

RS-232 Transceiver with AutoShutdown Plus

________________________________________________________________ Maxim Integrated Products

1

28

27

26

25

24

23

22

21

20

19

18

17

16

15

1

2

3

4

5

6

7

8

9

10

11

12

13

14

C1+

V+

C1-

T1IN

T2IN

INVALID

T3IN

R1OUT

R2OUT

T4IN

R3OUT

T5IN

R1OUTB

FORCEOFF

FORCEON

T5OUT

R3IN

T4OUT

R2IN

R1IN

T3OUT

T2OUT

T1OUT

V-

C2-

GND

C2+

SSOP

TOP VIEW

MAX3238

__________________Pin Configuration

19-1144; Rev 1; 10/02

PART

MAX3238CAI

MAX3238EAI

-40°C to +85°C

0°C to +70°C

TEMP RANGE

PIN-PACKAGE

28 SSOP

28 SSOP

______________Ordering Information

Typical Operating Circuit appears at end of data sheet.

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.