+5V-Powered, Multichannel RS-232
Drivers/Receivers
+3V
0V*
50%
50%
50%
+3V
INPUT
INPUT
0V
V
CC
OUTPUT
50%
GND
V+
0V
V-
OUTPUT
t
t
t
PLHR
PHLR
PHLS
t
PLHS
t
t
PLHT
PHLT
*EXCEPT FOR R2 ON THE MAX243
WHERE -3V IS USED.
Figure 1. Transmitter Propagation-Delay Timing
Figure 2. Receiver Propagation-Delay Timing
EN
1kΩ
R OUT
X
R
X
V
- 2V
R IN
X
CC
+3V
SHDN
a) TEST CIRCUIT
0V
150pF
0V
OUTPUT DISABLE TIME (t
)
DT
+3V
EN INPUT
V+
+5V
-5V
EN
OUTPUT ENABLE TIME (t
)
ER
0V
+3.5V
V-
RECEIVER
OUTPUTS
+0.8V
a) TIMING DIAGRAM
b) ENABLE TIMING
+3V
EN
0V
T
X
1 OR 0
EN INPUT
OUTPUT DISABLE TIME (t
)
DR
50pF
3kΩ
V
OH
V
- 0.5V
OH
RECEIVER
OUTPUTS
V
CC
- 2V
V
OL
+ 0.5V
b) TEST CIRCUIT
V
OL
c) DISABLE TIMING
Figure 3. Receiver-Output Enable and Disable Timing
______________________________________________________________________________________ 11
Figure 4. Transmitter-Output Disable Timing
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
