Datasheet

ST485B - ST485C Electrical characteristics
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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
OSD1
Driver short-circuit
current, V
O
=High
V
O
= -7 to 12V
(3)
35 25035250mA
I
OSD2
Driver short-circuit
current, V
O
=Low
V
O
= -7 to 12V
(3)
35 25035250mA
I
OSR
Receiver short-circuit
current
V
O
= 0V to V
CC
7 95795mA
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
= 0V
3. Applies to peak current. See typical Operating Characteristics.
Table 6. DC electrical characteristics (continued)
Symbol Parameter Test conditions
(1)
Value
Unit-40 to 85 °C -55 to 125 °C
Min. Typ. Max. Min. Max.
Table 7. Driver switching characteristics
Symbol Parameter Test conditions
(1)
Value
Unit-40 to 85 °C -55 to 125°C
Min. Typ. Max. Min. Max.
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 70 ns
t
SK
Output skew to output
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
(See Figure 4 and Figure 6)
510 10ns
t
TLH
t
THL
Rise or fall time
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF
(See Figure 4 and Figure 6)
3 15 40 3 45 ns
t
PZH
Output enable time
C
L
= 100pF, S2 = Closed
(See Figure 5 and Figure 7)
70 90 90 ns
t
PZL
Output enable time
C
L
= 100pF, S1 = Closed
(See Figure 5 and Figure 7)
70 90 90 ns
t
PLZ
Output disable time
C
L
= 15pF, S1 = Closed
(See Figure 5 and Figure 7)
70 90 90 ns
t
PHZ
Output disable time
C
L
= 15pF, S2 = Closed
(See Figure 5 and Figure 7)
70 90 90 ns
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.