Datasheet

ST3485EB, ST3485EC, ST3485EI, ST3485EIY
Electrical characteristics
DocID9102 Rev 11
7/24
Table 8: Transmitter electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for
ST3485ECDR, TA = -40 to 85 °C for ST3485EBDR, TA = -40 to 125 °C for ST3485EIDT and
ST3485EIYDT, unless otherwise specified. Typical values are referred to TA = 25 °C)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
V
OD
Differential drive output
R
L
= 100 Ω (RS-422) (Figure 2)
2
—
V
R
L
= 54 Ω (RS-485) (Figure 2)
1.5
R
L
= 60 Ω (RS-485) (Figure 3)
1.5
∆V
OD
Change in magnitude of
driver differential output
voltage for
complementary output
states
(1)
R
L
= 54 Ω or 100 Ω (Figure 2)
0.2
V
OC
Driver common mode
output voltage
R
L
= 54 Ω or 100 Ω (Figure 2)
3
∆V
OC
Change in magnitude of
driver common mode
output voltage
(1)
R
L
= 54 Ω or 100 Ω (Figure 2)
0.2
I
OSD
Driver short-circuit output
current
±250
mA
Notes:
(1)
∆V
OD
and ∆V
OC
are the changes in V
OD
and V
OC
, respectively, when the DI input changes state.
Table 9: Receiver electrical characteristics (VCC = 3 V to 3.6 V, TA = 0 to 70 °C for
ST3485ECDR, TA = -40 to 85 °C for ST3485EBDR, TA = -40 to 125 °C for ST3485EIDT and
ST3485EIYDT, unless otherwise specified. Typical values are referred to TA = 25 °C)
Symbol
Parameter
Test conditions
Min.
Typ.
Max.
Unit
V
TH
Receiver differential
threshold voltage
V
CM
= -7 V to 12 V, DE = 0
-0.2
0.2
V
∆V
TH
Receiver input hysteresis
V
CM
= 0 V
70
mV
V
OH
Receiver output high
voltage
I
OUT
= -4 mA, V
ID
= 200 mV (Figure 4)
2
V
V
OL
Receiver output low
voltage
I
OUT
= 4 mA, V
ID
= -200 mV (Figure 4)
0.4
I
OZR
3-state (high impedance)
output current at receiver
V
CC
= 3.6 V, V
O
= 0 V to V
CC
±1
µA
R
RIN
Receiver input resistance
V
CM
= -7 V to 12 V
24
kΩ
I
OSR
Receiver short-circuit
current
V
RO
= 0 V to V
CC
7
60
mA