Datasheet

LTC2872
12
2872f
TesT circuiTs
Figure 5. RS485 Driver Enable and Disable Timing Measurements
Figure 6. RS485 Receiver Propagation Delay Measurements (Note 5)
Figure 7. RS485 Receiver Enable and Disable Timing Measurements (Note 5)
2872 F07
t
ZLR485
t
LZR485
t
HZR485
t
ZHR485
½V
L
½V
L
V
L
V
OL
V
L
V
OH
0V
0V
0.5V
RXEN
RA
RA
RECEIVER
RA
RXEN
0V TO 3V
3V TO 0V
A
R
L
B
V
L
OR
GND
C
L
½V
L
0.5V
½V
L
2872 F05
t
ZLD485
,
t
ZLSD485
t
LZD485
t
HZD485
t
ZHD485
,
t
ZHSD485
½V
CC
½V
CC
V
L
V
OL
V
CC
V
OH
0V
0V
0.5V
DXEN
Y OR Z
Z OR Y
DRIVER
DY
DXEN
V
L
OR
GND
Y
R
L
Z
GND
OR
V
CC
V
CC
OR
GND
R
L
C
L
C
L
½V
L
0.5V
½V
L
2872 F06
RECEIVER
V
CM
±V
AB
/2
A
B
RA
±V
AB
/2
C
L
t
PLHR485
t
SKEWR485
= t
PLHR485
– t
PHLR485
t
RR485
90%
0V
½V
L
A–B
RA
10%
t
PHLR485
t
FR485
90%
0V
–V
AB
V
AB
½V
L
10%
V
CC