Datasheet

LTC485
7
485fk
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SWITCHING TIME WAVEFORMS
Figure 6. Driver Enable and Disable Times
1.5V
t
ZL
2.3V
2.3V
t
ZH
1.5V
t
LZ
0.5V
0.5V
t
HZ
f = 1MHz, t
r
≤ 10ns, t
f
≤ 10ns
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
3V
0V
DI
5V
V
OL
V
OH
0V
A, B
A, B
485 F06
Figure 7. Receiver Propagation Delays
1.5V
t
PHL
f = 1MHz, t
r
≤ 10ns, t
f
≤ 10ns
R
–V
OD2
A, B
0V
1.5V
t
PLH
OUTPUT
INPUT
V
OD2
V
OL
V
OH
485 F07
Figure 8. Receiver Enable and Disable Times
1.5V
t
ZL
1.5V
1.5V
t
ZH
1.5V
t
LZ
0.5V
0.5V
t
HZ
f = 1MHz, t
r
≤ 10ns, t
f
≤ 10ns
OUTPUT NORMALLY LOW
OUTPUT NORMALLY HIGH
3V
0V
RE
5V
0V
R
R
485 F08
FUNCTION TABLES
LTC485 Transmitting
INPUTS
LINE
CONDITION
OUTPUTS
RE DE DI B A
X 1 1 No Fault 0 1
X 1 0 No Fault 1 0
X 0 X X Z Z
X 1 X Fault Z Z
LTC485 Receiving
INPUTS OUTPUTS
RE DE A – B R
0 0 ≥ 0.2V 1
0 0 ≤ –0.2V 0
0 0 Inputs Open 1
1 0 X Z