5

SP490EDS/14

SP490E Enhanced Full Duplex RS-485 Transceivers

© Copyright 2000 Sipex Corporation

ABSOLUTE MAXIMUM RATINGS

These are stress ratings only and functional operation of the device at

these ratings or any other above those indicated in the operation sections

of the specifications below is not implied. Exposure to absolute maximum

rating conditions for extended periods of time may affect reliability.

V

Input Voltages

Logic...................................................-0.5V to (V

Drivers................................................-0.5V to (V

Receivers..................................................................

±14V

Output Voltages

Logic...................................................-0.5V to (V

Drivers......................................................................

±14V

Receivers...........................................-0.5V to (V

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

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

SPECIFICATIONS

T

PARAMETERS

MIN.

TYP.

MAX.

UNITS

CONDITIONS

SP491E DRIVER

DC Characteristics

Differential Output Voltage

GND

V

CC

Volts

Unloaded; R =

∞ ; see Figure 1

Differential Output Voltage

2

V

CC

Volts

With Load; R = 50

Ω; (RS-422);

see Figure 1

Differential Output Voltage

1.5

V

CC

Volts

With Load; R = 27

Ω; (RS-485);see Figure 1

Change in Magnitude of Driver

Differential Output Voltage for

Complimentary States

0.2

Volts

R = 27

Ω or R = 50Ω; see Figure 1

Driver Common-Mode

Output Voltage

3

Volts

R = 27

Ω 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

±10

µA

Applies to D, REB, DE

Driver Short-Circuit Current

V

250

mA

-7V

≤ V

V

250

mA

-7V

≤ V

SP491E DRIVER

AC Characteristics

Maximum Data Rate

10

Mbps

R

Driver Input to Output

20

30

60

ns

t

see Figures 3 and 5

Driver Input to Output

20

30

60

ns

t

see Figures 3 and 5

Driver Skew

5

10

ns

see Figures 3 and 5,

t

Driver Rise or Fall Time

3

15

40

ns

From 10% to 90%; R

C

Driver Enable to Output HIGH

40

70

ns

C

4 and 6; S

Driver Enable to Output LOW

40

70

ns

C

4 and 6; S

Driver Disable Time from LOW

40

70

ns

C

4 and 6; S

Driver Disable Time from HIGH

40

70

ns

C

4 and 6; S