MAX3243

3V TO 5.5V MULTICHANNEL RS232 LINE DRIVER/RECEIVER

WITH ±15kV ESD (HBM) PROTECTION

SLLS350L − APRIL 1999 − REVISED MARCH 2004

10

POST OFFICE BOX 655303

APPLICATION INFORMATION

RIN4

DOUT2

DOUT3

ROUT1

FORCEOFF

RIN5

INVALID

ROUT2

DOUT1

ROUT2B

DIN3

DIN2

ROUT3

ROUT4

DIN1

ROUT5

C4

+

−

+

−

C3†

VCC

C2+

C2−

C1

C1+

GND

V−

C1−

FORCEON

C2

+

−

CBYPASS

= 0.1

µF

V+

+

−

+

−

RIN1

RIN2

RIN3

RS-232 Inputs

Logic Outputs

Logic Inputs

RS-232 Outputs

VCC

C1

C2, C3, and C4

3.3 V

± 0.3 V

5 V

± 0.5 V

3 V to 5.5 V

0.1

µF

0.047

µF

0.1

µF

0.1

µF

0.33

µF

0.47

µF

† C3 can be connected to VCC or GND.

NOTES: A. Resistor values shown are nominal.

B. Nonpolarized ceramic capacitors are acceptable. If polarized

tantalum or electrolytic capacitors are used, they should be

connected as shown.

VCC vs CAPACITOR VALUES

1

2

4

5

6

7

8

9

10

11

12

13

14

3

28

27

26

25

24

23

22

21

20

19

18

17

16

15

5 k

Ω

5 k

Ω

5 k

Ω

5 k

Ω

5 k

Ω

Figure 6. Typical Operating Circuit and Capacitor Values