±15kV ESD-Protected, Down to 10nA, 3.0V to 5.5V,

Up to 1Mbps, True RS-232 Transceivers

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7

*These pins have an active positive feedback resistor internal to the MAX3237E, allowing unused inputs to be left unconnected.

Pin Description

PIN

MAX3222E

MAX3232E

MAX3241E

SO/DIP

TSSOP/

SSOP

SO/DIP/

SSOP

TSSOP

MAX3237E

SSOP/SO

QFN

MAX3246E

NAME

FUNCTION

11

——

13*

23

22

B3

EN

Receiver Enable. Active low.

2

2

1

2

28

28

28

F3

C1+

Positive Terminal of Voltage-

Doubler Charge-Pump

Capacitor

3

3

2

3

27

27

27

F1

V+

+5.5V Generated by the

Charge Pump

4

4

3

4

25

24

23

F4

C1-

Negative Terminal of Voltage-

Doubler Charge-Pump

Capacitor

5

5

4

5

1

1

29

E1

C2+

Positive Terminal of Inverting

Charge-Pump Capacitor

6

6

5

6

3

2

30

D1

C2-

Negative Terminal of Inverting

Charge-Pump Capacitor

7

7

6

7

4

3

31

C1

V-

-5.5V Generated by the

Charge Pump

8, 15

8, 17

7, 14

8, 17

5, 6, 7,

10, 12

9, 10,

11

6, 7,

8

F6, E6, D6

T_OUT

RS-232 Transmitter Outputs

9, 14

9, 16

8, 13

9, 16

8, 9, 11

4–81–5

A4, A5,

A6, B6, C6

R_IN

RS-232 Receiver Inputs

10, 13

10, 15

9, 12

12, 15

18, 20,

21

15–19

13, 14,

15, 17,

18

C2, B1,

A1, A2, A3

R_OUT

TTL/CMOS Receiver Outputs

11, 12

12, 13

10, 11

13, 14

17*, 19*,

22*, 23*,

24*

12, 13,

14

10, 11,

12

E3, E2, D2

T_IN

TTL/CMOS Transmitter Inputs

16

18

15

18

2

25

24

F5

GND

Ground

17

19

16

19

26

26

26

F2

+3.0V to +5.5V Supply Voltage

18

20

——

14*

22

21

B2

SHDN

Shutdown Control. Active low.

—

11, 14

—

1, 10, 11,

20

——

9, 16,

25, 32

C3, D3, B4,

C4, D4, E4,

B5, C5, D5,

E5

N.C.

No Connection. For

MAX3246E, these locations

are not populated with solder

bumps.

——

—

—

15*

——

—

MBAUD

MegaBaud Control Input.

Connect to GND for normal

operation; connect to VCC for

1Mbps transmission rates.

——

—

—

16

20, 21

19, 20

—

R_OUTB

Noninverting Complementary

Receiver Outputs. Always

active.