Datasheet

ST485ERB Electrical characteristics
7/19
(V
CC
= 5 V ± 5 %, T
A
= T
MIN
to T
MAX
, unless otherwise specified. Typical values are referred
to T
A
= 25 °C)
I
CC
No load supply current
(2)
V
RE
= 0V or V
CC
V
DE
= V
CC
V
DE
= 0V
400
300
900
500
µA
µA
I
OSD1
Driver short-circuit current,
V
O
=High
V
O
= -7 to 12V
(3)
35 250 mA
I
OSD2
Driver short-circuit current,
V
O
=Low
V
O
= -7 to 12V
(3)
35 250 mA
I
OSR
Receiver short-circuit
current
V
O
= 0V to V
CC
795mA
1. All currents into device pins are positive; all cuttents out of device pins are negative; all voltages are
referenced to device ground unless specified.
2. Supply current specification is valid for loaded transmitters when V
DE
= 0 V
3. Applies to peak current. See typical Operating Characteristics.
Table 8. Driver switching characteristics
Symbol Parameter Test conditions
(1)
1. All currents into device pins are positive; all cuttents out of device pins are negative; all voltages are
referenced to device ground unless specified.
Min. Typ. Max. Unit
t
PLH
t
PHL
Propagation delay input to
output
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
(see Figure 4 and Figure 6)
10 30 60 ns
t
SK
Output skew to output
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
(see Figure 4 and Figure 6)
510ns
t
TLH
t
THL
Rise or fall time
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
(see Figure 4 and Figure 6)
31540ns
t
PZH
Output enable time
C
L
= 100pF, S2 = Closed
(see Figure 5 and Figure 7)
70 90 ns
t
PZL
Output enable time
C
L
= 100pF, S1 = Closed
(see Figure 5 and Figure 7)
70 90 ns
t
PLZ
Output disable time
C
L
= 15pF, S1 = Closed
(see Figure 5 and Figure 7)
70 90 ns
t
PHZ
Output disable time
C
L
= 15pF, S2 = Closed
(see Figure 5 and Figure 7)
70 90 ns
C
AB
Output AB capacitance 43 pF
Table 7. DC electrical characteristics (continued)
Symbol Parameter Test conditions
(1)
Min. Typ. Max. Unit