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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com

SP3490_349_02_0270

ELECTRICAL CHARACTERISTICS

T

PARAMETERS

MIN.

TYP.

MAX.

UNITS CONDITIONS

SP3491 DRIVER

DC Characteristics

Differential Output Voltage

GND

Vcc

Volts

Unloaded; R = ∞Ω ; Figure 1

Differential Output Voltage

2

Vcc

Volts

With Load; R = 50Ω (RS-422);

Figure 

Differential Output Voltage

.5

Vcc

Volts

With Load; R = 27Ω (RS-485);

Figure 

Change in Magnitude of Driver

Differential Output Voltage for

Complimentary states

0.2

Volts

R = 27Ω or R = 50Ω; Figure 1

Driver Common Mode Output

Voltage

3

Volts

R = 27Ω or R = 50Ω; Figure 1

Input High Voltage

2.0

Volts

Applies to DE, D, REB

Input Low Voltage

0.8

Volts

Applies to DE, D, REB

Input Current

+/-0

µA

Applies to DE, D, REB

Driver Short Circuit Current

V

+/-250

mA

-7V ≤ V

V

+/-250

mA

-7V ≤ V

SP3491 DRIVER

AC Characteristics

Max. Transmission Rate

0

Mbps

Driver Input to Output, t

PLH

20

40

60

ns

Figures 2 & 9

Driver Input to Output, t

PHL

20

40

60

ns

Figures 2 & 9

Differential Driver Skew

2

ns

|t

Figures 2 and 9

Driver Rise or Fall Time

5

20

ns

From 0%-90%; Figures 3 and 0

Driver Enable to Output HIGH

52

20

ns

Figures 4 and 

Driver Enable to Output LOW

60

20

ns

Figures 5 and 

Driver Disable from LOW

40

20

ns

Figures 5 and 

Driver Disable from HIGH

60

20

ns

Figures 4 and