MAX3140 Maxim, MAX3140 Datasheet - Page 13

• Manufacturer Part Number: MAX3140
• Description: SPI/MICROWIRE-Compatible UART with Integrated True Fail-Safe RS-485/RS-422 Transceivers
• Manufacturer: Maxim

Figure 1. Driver DC Test Load
Figure 3. Driver Timing Test Circuit
Figure 5. Driver Propagation Delays
SPI/MICROWIRE-Compatible UART with Integrated
V
DIFF
DI
-V
3V
V
0
Z
Y
O
0
O
V
O
1.5V
t
R
10%
1/2 V
DI
O
Y
Z
______________________________________________________________________________________
DE
True Fail-Safe RS-485/RS-422 Transceivers
V
CC
90%
t
PLH
V
OD
V
t
SKEW =
Y
DIFF
Z
= V (Y) - V (Z)
V
ID
|
t
PLH
- t
R
R
PHL
t
PHL
R
C
C
|
DIFF
t
L1
L2
F
90%
V
OC
1.5V
10%
1/2 V
O
Figure 2. Receiver Enable/Disable Timing Test Load
Figure 4. Driver Enable/Disable Timing Test Load
Figure 6. Driver Enable and Disable Times
DE
Y, Z
Y, Z
V
3V
OL
0
0
RECEIVER
OUTPUT
UNDER TEST
OUTPUT
15pF
1.5V
C
TEST POINT
L
2.3V
2.3V
C
t
t
ZL(SHDN)
ZH(SHDN)
L
OUTPUT NORMALLY HIGH
OUTPUT NORMALLY LOW
500
1k
, t
, t
ZL
ZH
S1
S2
t
t
HZ
LZ
S1
S2
1k
1.5V
V
V
OL
OH
V
V
+0.5V
-0.5V
CC
CC
13