Complete, Isolated RS-485/RS-422

Data Interface

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3

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

R = 50

Ω (RS-422)

2

Differential Driver Output

(With Load)

R = 27

Ω (RS-485), Figure 4

1.5

5.0

V

Differential

0.3

Change in Magnitude of

Differential Output Voltage for

Complementary Output States

R = 27

Ω or 50Ω,

Figure 4

Common mode

0.3

V

Driver Common-Mode Output

Voltage

R = 27

Ω or 50Ω, Figure 4

4

V

MAX1490A/B

0.25

MAX1480A/B/C

1

MAX1490A/B

0.2

Input Current (A, B)

DE´ = 0V,

or 5.5V

MAX1480A/B/C

0.8

mA

Receiver Input Resistance

-7V

12

k

Ω

Receiver Differential Threshold

Voltage

-7V

-0.2

+0.2

V

Receiver Input Hysteresis

70

mV

Receiver Output/Receiver Output

Low Voltage

Using resistor values listed in

Tables 1 and 2

0.4

V

Receiver Output/Receiver Output

High Current

250

µA

Driver Short-Circuit Current

-7V

100

mA

ELECTRICAL CHARACTERISTICS (continued)

SWITCHING CHARACTERISTICS—MAX1480A/MAX1490A

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

100

275

Driver Input to Output

Propagation Delay

= 100pF

100

275

ns

Driver Output Skew

= 100pF

25

90

ns

Driver Rise or Fall Time

= 100pF

15

40

ns

Driver Enable to Output High

(MAX1480A Only)

0.2

1.5

µs

Driver Enable to Output Low

(MAX1480A Only)

0.2

1.5

µs

Driver Disable Time from Low

(MAX1480A Only)

0.2

1.5

µs

Driver Disable Time from High

(MAX1480A Only)

0.2

1.5

µs

100

225

Receiver Input to Output

Propagation Delay

= 100pF

100

225

ns