LTC1387 Linear Technology, LTC1387 Datasheet - Page 8

• Manufacturer Part Number: LTC1387
• Description: Single 5V RS232/RS485 Multiprotocol Transceiver
• Manufacturer: Linear Technology

SWITCHI G WAVEFOR S
LTC1387
8
U
B – A
Z – Y
Y, Z
DXEN
R
–V
Y, Z
Z, Y
V
D
D
–V
V
–V
V
OD2
OD2
3V
V
V
OH
0V
OL
3V
0V
V
V
OH
0V
O
O
Y
Z
3V
0V
5V
O
O
OL
V
O
f = 1MHz: t
f = 100kHz: t
f = 1MHz: t
f = 100kHz: t
W
0V
Figure 8. RS485 Driver Enable and Disable Times
1.5V
1.5V
Figure 9. RS485 Receiver Propagation Delays
1.5V
Figure 10. RS232 Driver Propagation Delays
10%
t
t
t
PHL
PLH
PLH
50%
t
t
Figure 7. RS485 Driver Propagation Delays
ZL
ZH
f = 1MHz: t
r
r
r
t
r
r
10ns: t
10ns: t
10ns: t
0V
1.5V
10ns: t
2.3V
2.3V
90%
t
SKEW
r
f
f
f
10ns: t
f
10ns (FAST SLEW RATE MODE)
OUTPUT NORMALLY HIGH
10ns (FAST SLEW RATE MODE)
OUTPUT NORMALLY LOW
10ns (SLOW SLEW RATE MODE)
10ns (SLOW SLEW RATE MODE)
1/2 V
f
V
DIFF
10ns
O
= V(A) – V(B)
OUTPUT
INPUT
1.5V
0V
1.5V
1.5V
t
t
t
90%
t
PLH
t
PHL
PHL
LZ
HZ
t
f
0V
50%
1.5V
10%
0.5V
t
0.5V
SKEW
LTC1387 • F10
LTC1387 • F07
LTC1387 • F09
LTC1387 • F08