Datasheet

Electrical characteristics ST485B - ST485C
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4 Electrical characteristics
V
CC
= 5 V ± 5 %, T
A
= T
MIN
to T
MAX
, unless otherwise specified. Typical values are referred
to T
A
= 25 °C
Table 6. DC electrical characteristics
Symbol Parameter Test conditions
(1)
Value
Unit-40 to 85 °C -55 to 125 °C
Min. Typ. Max. Min. Max.
V
OD1
Differential driver output
(no load)
55V
V
OD2
Differential driver output
(with load)
R
L
= 27Ω (RS-485) Figure 2
R
L
= 50Ω (RS-422) Figure 2
1.5
5
5
1.4
5
5
V
V
ΔV
OD
Change in magnitude of
driver differential output
voltage for complementary
output states
R
L
= 27Ω or 50Ω Figure 2 0.2 0.2 V
V
OC
Driver common-mode
output voltage
R
L
= 27Ω or 50Ω Figure 2 33V
ΔV
OC
Change in magnitude of
driver common-mode
output voltage for
complementary output
states
R
L
= 27Ω or 50Ω Figure 2 0.2 0.2 V
V
IH
Input high voltage RE, DE, DI 2.0 2.0 V
V
IL
Input low voltage RE, DE, DI 0.8 0.8 V
I
IN1
Input current RE, DE, DI ± 2 ± 2µA
I
IN2
Input current (A, B)
V
CM
= 0V or 5.25V, V
DE
= 0V
V
IN
= 12V
V
IN
= -7V
1
-0.8
1
-0.8
mA
mA
V
TH
Receiver differential
threshold voltage
V
CM
= -7 to 12V -0.2 0.2 -0.2 0.2 V
ΔV
TH
Receiver input hysteresis V
CM
= 0V 70 mV
V
OH
Receiver output high
voltage
I
O
= -4mA, V
ID
= 200mV 3.5 3.4 V
V
OL
Receiver output low
voltage
I
O
= 4mA, V
ID
= -200mV 0.4 0.55 V
I
OZR
3-state (high impedance)
output current at receiver
V
O
= 0.4 to 2.4V ± 1 ± 1µA
R
IN
Receiver input resistance V
CM
= -7 to 12V 24 24 kΩ
I
CC
No load supply current
(2)
V
RE
= 0V or V
CC
V
DE
= V
CC
V
DE
= 0V
400
300
900
500
900
500
µA
µA