5

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

SP490,49_00_07408

ABSOLUTEMAXIMUMRATINGS

Thesearestressratingsonlyandfunctionaloperationofthedevice

attheseratingsoranyotherabovethoseindicatedintheoperation

sections of the specifications below is not implied. Exposure to

absolute maximum rating conditions for extended periods of time

may affect reliability.

V

InputVoltages

Logic.................................................-0.5Vto(V

Drivers..............................................-0.5Vto(V

Receivers................................................................±14V

OutputVoltages

Logic................................................-0.5Vto(V

Drivers....................................................................±14V

Receivers.........................................-0.5Vto(V

Storage Temperature.....................................................-65˚C to +150

Power Dissipation.................................................................1000mW

T

PARAMETERS

MIN.

TYP.

MAX. UNITS CONDITIONS

SP491DRIVER

DCCharacteristics

Differential Output Voltage

GND

V

CC

Volts

Unloaded; R = ∞ ; see figure 1

Differential Output Voltage

2

V

CC

Volts

With Load; R = 50Ω; (RS422);

see figure 1

Differential Output Voltage

.5

V

CC

Volts

With Load; R = 27Ω; (RS485); see

figure 1

Change in Magnitude of Driver

Differential Output Voltage for

Complimentary States

0.2

Volts

R = 27Ω or R = 50Ω; see figure 1

Driver Common-Mode

Output Voltage

3

Volts

R = 27Ω or R = 50Ω; see figure 1

Input High Voltage

2.0

Volts

Applies to D, REB, DE

Input Low Voltage

0.8

Volts

Applies to D, REB, DE

Input Current

±0

µA

Applies to D, REB, DE

Driver Short-Circuit Current

V

35

250

mA

-7V ≤ V

V

35

250

mA

-7V ≤ V

SP491DRIVER

ACCharacteristics

Maximum Data Rate

5

Mbps

REB = 5V, DE = 5V

Driver Input to Output

20

30

60

ns

t

see figures 3 and 6

Driver Input to Output

20

30

60

ns

t

see figures 3 and 6

Driver Skew

5

0

ns

see figures 3 and 6,

t

Driver Rise or Fall Time

3

5

40

ns

From 0% to 90%; R

C

Driver Enable to Output High

40

70

ns

C

4 and 7; S

Driver Enable to Output Low

40

70

ns

C

4 and 7; S

Driver Disable Time from Low

40

70

ns

C

4 and 7; S

Driver Disable Time from High

40

70

ns

C

4 and 7; S

ELECTRICALCHARACTERISTICS