SN75185

MULTIPLE RS-232 DRIVERS AND RECEIVERS

SLLS181A – DECEMBER 1994 – REVISED NOVEMBER 1998

9

POST OFFICE BOX 655303

APPLICATION INFORMATION

outputs are shorted to

±15 V and the power supplies are at low and provide low-impedance paths to ground (see

Figure 15).

VDD

VSS

±15 V

Output

VDD

VSS

SN75185

SN75185

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

11

12

13

14

15

16

17

18

19

20

GND

RY5

DA3

RY4

DA2

DA1

RY3

RY2

RY1

VCC

VSS

RA5

DY3

RA4

DY2

DY1

RA3

RA2

RA1

VDD

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

C1†

C3†

† 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 upon the line length and desired slew rate, but typically

is 330 pF.

C2†

Figure 16. Typical Connection