Datasheet

SN75196
MULTIPLE RS-232 DRIVERS AND RECEIVERS
SLLS188B – MAY 1995 – REVISED APRIL 1998
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
APPLICATION INFORMATION
Diodes placed in series with the V
DD
and V
SS
terminals protect the SN75196 in the fault condition when the device
outputs are shorted to V
DD
or V
SS
and the power supplies are at low and provide low-impedance paths to ground
(see Figure 15).
V
DD
V
SS
±15 V
Output
V
DD
V
SS
SN75196 SN75196
Figure 15. Power-Supply Protection to Meet Power-Off Fault Conditions of TIA/EIA-232-F
SN75196
5 V
TL16C450
ACE
1
5
6
9
12 V
–12 V
TIA/EIA-232-F
DB9S
Connector
C2
†
C5
†
†
See Figure 10 to select the correct values for the loading capacitors (C1, C2, C3, C4, and C5), which may be 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 is typically 330 pF.
NOTE A: To use the receivers only, V
DD
and V
SS
must both be powered or tied to ground.
C4
†
C3
†
C1
†
RI
DTR
CTS
SO
RTS
SI
DSR
DCD
43
37
40
13
36
11
41
42
10
9
8
7
6
5
4
3
2
1
GND
5DA
3RY
4DA
2RY
1RY
2DA
1DA
V
CC
3DA
V
SS
5DY
3RA
4DY
2RA
1RA
2DY
1DY
V
DD
3DY
11
12
13
14
15
16
17
18
19
20
RI
DTR
CTS
TX
RTS
RX
DSR
DCD
Figure 16. Typical TIA/EIA-232-F Connection