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

Differential drive output

= 100 Ω (RS-422) (Figure 2)

2

—

V

= 54 Ω (RS-485) (Figure 2)

1.5

= 60 Ω (RS-485) (Figure 3)

1.5

Change in magnitude of

driver differential output

voltage for

complementary output

states (1)

= 54 Ω or 100 Ω (Figure 2)

0.2

Driver common mode

output voltage

= 54 Ω or 100 Ω (Figure 2)

3

Change in magnitude of

driver common mode

output voltage(1)

= 54 Ω or 100 Ω (Figure 2)

0.2

Driver short-circuit output

current

±250

mA

Notes:

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

Receiver differential

threshold voltage

-0.2

0.2

V

Receiver input hysteresis

70

mV

Receiver output high

voltage

2

V

Receiver output low

voltage

0.4

3-state (high impedance)

output current at receiver

±1

µA

Receiver input resistance

24

kΩ

Receiver short-circuit

current

7

60

mA