3V
0V
1.5V
1.5V
INPUT
3V
0V
IN
1.5V
1.5V
t
PLH
t
PHL
VOH
VOM
VOM
Y OUTPUT
t
DO1
t
DO2
VOL
2.0V
t
PHL
t
PLH
90%
90%
VOH
50%
10%
50%
10%
OUT
Z OUTPUT
VOM
VOM
-2.0V
VOL
t
TD
t
TD
V
OH + VOL
≈ 1.5V
VOM
=
2
Figure 9. Driver Differential Output Delay and
Transition Time Waveforms
Figure 8. Driver Propagation Delay Waveforms
3V
1.5V
1.5V
DE
0V
3V
t
PHZ
t
PZH
INPUT
1.5V
1.5V
V
OH
0.25V
0.25V
0V
OUTPUT
HIGH
V
OM
t
RPLH
t
RPHL
0V
VCC
VOM
OUTPUT
V
OM
t
PZL
t
PLZ
V
CC
0V
OUTPUT
LOW
V
OM
V
2
CC
VOM
=
V
OL
V
OH + VOL
2
≈ 1.5V
V
OM
=
Figure 10. Driver Enable and Disable Timing Waveforms
Figure 11. Receiver Propagation Delay Waveforms
S1 is open
S2 is closed
S3 = 1.5V
S1 is closed
S2 is open
S3 = -1.5V
3V
3V
1.5V
1.5V
1.5V
1.5V
RE
RE
0V
0V
t
t
PRZL
PRSL
t
PRZH
PRSH
t
PRHZ
t
PRLZ
t
V
CC
VOH
10%
1.5V
OUTPUT
OUTPUT
1.5V
10%
V
OL
0V
Figure 12. Receiver Enable and Disable Waveforms
NOTE 1: The input pulse is supplied by a generator with the following characteristics:
PRR=250KHz, 50% duty cycle, tr < 6.0ns, Z0=50Ω.
NOTE 2: CL includes probe and stray capacitance.
10/16/02
SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers
© Copyright 2002 Sipex Corporation
8
SIPEX [ SIPEX CORPORATION ]
