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

Up to 1Mbps, True RS-232 Transceivers

*

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

TQFN

SO/

DIP

TSSOP/

SSOP

TQFN

SO/DIP/

SSOP/

16-PIN

TSSOP

20-PIN

TSSOP

MAX3237E SSOP/

SO/

TSSOP

TQFN

MAX3246E

NAME

FUNCTION

19

1

1

—

—

—

13*

23

22

B3

EN

Receiver Enable. Active

low.

1

2

2

16

1

2

28

28

28

F3

C1+

Positive Terminal of

Voltage-Doubler Charge-

Pump Capacitor

20

3

3

15

2

3

27

27

27

F1

V+

+5.5V Generated by the

Charge Pump

2

4

4

1

3

4

25

24

23

F4

C1-

Negative Terminal of

Voltage-Doubler Charge-

Pump Capacitor

3

5

5

2

4

5

1

1

29

E1

C2+

Positive Terminal of

Inverting Charge-Pump

Capacitor

4

6

6

3

5

6

3

2

30

D1

C2-

Negative Terminal of

Inverting Charge-Pump

Capacitor

5

7

7

4

6

7

4

3

31

C1

V-

-5.5V Generated by the

Charge Pump

6, 15

8,

15

8, 17

5,

12

7, 14

8, 17

5, 6, 7,

10, 12

9,

10,

11

6,

7,

8

F6, E6,

D6

T_OUT

RS-232 Transmitter

Outputs

7, 14

9,

14

9, 16

6,

11

8, 13

9, 16

8, 9, 11

4–8

1–5

A4, A5,

A6, B6,

C6

R_IN

RS-232 Receiver Inputs

8, 13

10,

13

10, 15

7,

10

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

10, 11

11,

12

12, 13

8, 9

10, 11

13,

14

17*, 19*,

22*, 23*,

24*

12,

13,

14

10,

11,

12

E3, E2,

D2

T_IN

TTL/CMOS Transmitter

Inputs

Maxim Integrated

7

MAX3222E/MAX3232E/MAX3237E/

MAX3241E/MAX3246E