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APPLICATION INFORMATION

±15 V

Output

SN75185

SN75185

11

12

13

14

15

16

17

18

19

20

GND

RY5

DA3

RY4

DA2

DA1

RY3

RY2

RY1

RA5

DY3

RA4

DY2

DY1

RA3

RA2

RA1

10

9

8

7

6

5

4

3

2

1

43

37

40

13

36

11

41

42

RI

DTR

CTS

SO

RTS

SI

DSR

DCD

R1

DTR

CTS

TX

RTS

RX

DSR

DCD

SN75185

5 V

TL16C450

ACE

1

5

6

9

12 V

−12 V

TIA/EIA-232-F

DB9S

Connector

SN75185

MULTIPLE RS-232 DRIVERS AND RECEIVERS

SLLS181D–DECEMBER 1994–REVISED JANUARY 2006

condition, the device outputs are shorted to ±15 V, and the power supplies are at low and provide low-impedance

paths to ground (see Figure 15).

Figure 15. Power-Supply Protection to Meet Power-Off Fault Conditions of TIA/EIA-232-F

(1) See Figure 10 to select the correct values for the loading capacitors (C1, C2, and C3), which are required to meet the

RS-232 maximum slew-rate requirement of 30 V/μs. The value of the loading capacitors required depends on the line

length and desired slew rate, but typically is 330 pF.

Figure 16. Typical Connection

12