LTC1484 Linear Technology, LTC1484 Datasheet - Page 10

• Manufacturer Part Number: LTC1484
• Description: Low Power RS485 Transceiver with Receiver Fail-Safe
• Manufacturer: Linear Technology

LTC1484
SWITCHI G TI E WAVEFOR S
10
A – B
A, B
A, B
RO
DE
RO
RO
DI
RE
– V
U
V
–V
V
V
V
OD2
OD2
3V
0V
V
3V
0V
5V
OH
0V
5V
OL
OL
5V
0V
5V
0V
O
O
B
A
NOTE: DE = 1
NOTE: A, B ARE THREE-STATED WHEN DE = 0, 1k PULL-UP OR 1k PULL-DOWN
NOTE: t
NOTE: DE = 0, RO IS THREE-STATED IN SHUTDOWN, 1k PULL-UP FOR NORMALLY LOW OUTPUT,
1k PULL-DOWN FOR NORMALLY HIGH OUTPUT
V
O
1/2 V
W
SKD
O
= |t
10%
t
0V
PHL
r
1.5V
1.5V
1.5V
– t
PLH
2.3V
2.3V
1.5V
1.5V
90%
1.5V
|, RE = 0
t
t
t
t
PLH
t
50%
t
t
SKEW
ZL(SHDN)
ZH(SHDN)
PHL
ZL(SHDN),
ZH(SHDN),
Figure 9. Receiver Enable and Shutdown Timing
Figure 7. Driver Enable and Disable Timing
, t
, t
Figure 8. Receiver Propagation Delays
t
t
Figure 6. Driver Propagation Delays
ZL
ZL
ZH
ZH
W
f = 1MHz, t
f = 1MHz, t
OUTPUT NORMALLY HIGH
OUTPUT NORMALLY LOW
f = 1MHz, t
OUTPUT NORMALLY HIGH
OUTPUT NORMALLY LOW
f = 1MHz, t
V
O
= V(A) – V(B)
r
r
10ns, t
r
10ns, t
OUTPUT
r
INPUT
10ns, t
10ns, t
f
f
10ns
f
10ns
f
10ns
10ns
t
PHL
t
PLH
t
t
t
t
HZ
50%
LZ
HZ
LZ
t
f
1.5V
1.5V
0V
1.5V
90%
10%
t
SKEW
0.5V
1.5V
0.5V
0.5V
0.5V
1484 F08
1484 F06
1484 F07
1484 F09