Datasheet

LTC2870/LTC2871
14
28701f
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)
28701 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/
DX485
Y OR Z
Z OR Y
DRIVER
DY/DI
DXEN/DX485
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
28701 F06
RECEIVER
V
CM
±V
AB
/2
A
B
RA/RO
±V
AB
/2
C
L
t
PLHR485
t
SKEWR485
= t
PLHR485
– t
PHLR485
t
RR485
90%
0V
½V
L
A-B
RA/RO
10%
t
PHLR485
t
FR485
90%
0V
–V
AB
V
AB
½V
L
10%
V
L
28701 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/
RX485
RA/RO
RA/RO
RECEIVER
RA/RO
RXEN/RX485
0V TO 3V
3V TO 0V
A
R
L
B
V
L
OR
GND
C
L
½V
L
0.5V
½V
L