®
SP490/SP491
Full Duplex RS-485 Transceivers
FEATURES
■
+5V Only
■
Low Power BiCMOS
■
Driver/Receiver Enable (SP491)
■
RS-485 and RS-422 Drivers/Receivers
■
Pin Compatible with LTC490 and
SN75179 (SP490)
■
Pin Compatible with LTC491 and
SN75180 (SP491)
Now Available in Lead Free Packaging
DESCRIPTION
The
SP490
is a low power differential line driver/receiver meeting RS-485 and RS-422
standards up to 5Mbps. The
SP491
is identical to the
SP490
with the addition of driver and
receiver tri-state enable lines. Both products feature
±200mV
receiver input sensitivity, over
wide common mode range. The
SP490
is available in 8-pin plastic DIP and 8-pin NSOIC
packages for operation over the commercial and industrial temperature ranges. The
SP491
is available in 14-pin DIP and 14-pin NSOIC packages for operation over the commercial and
industrial temperature ranges.
BLOCK DIAGRAMS
NC 1
14 Vcc
13 NC
12 A
Vcc 1
R 2
R 2
8 A
R
11 B
R
REB 3
7 B
6 Z
DE 4
10 Z
D 5
D 3
GND 4
D
5 Y
D
GND 6
GND 7
9 Y
8 NC
SP490
SP491
Date: 02/24/05
SP490/491 Full Duplex RS-485 Transceivers
© Copyright 2005 Sipex Corporation
1
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
CC
....................................................................................................+7V
Input Voltages
Drivers................................................-0.5V to (V
CC
+0.5V)
Receivers..................................................................±14V
Output Voltages
Drivers......................................................................±14V
Receivers...........................................-0.5V to (V
CC
+0.5V)
Storage Temperature....................................................-65˚C to +150˚
Power Dissipation.....................................................................1000mW
ELECTRICAL CHARACTERISTICS
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
SP490 DRIVER
DC Characteristics
Differential Output Voltage
Differential Output Voltage
Differential Output Voltage
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
Driver Common-Mode
Output Voltage
Input High Voltage
Input Low Voltage
Input Current
Driver Short-Circuit Current
V
OUT
= HIGH
V
OUT
= LOW
SP490 DRIVER
AC Characteristics
Maximum Data Rate
Driver Input to Output
Driver Input to Output
Driver Skew
Driver Rise or Fall Time
MIN.
TYP.
MAX.
UNITS
CONDITIONS
GND
2
1.5
V
CC
V
CC
V
CC
0.2
3
Volts
Volts
Volts
Volts
Volts
Volts
Volts
µA
mA
mA
Unloaded; R =
∞
;
see figure 1
With Load; R = 50Ω; (RS422);
see figure 1
With Load; R = 27Ω; (RS485);
see figure 1
R = 27Ω or R = 50Ω;
see figure 1
R = 27Ω or R = 50Ω;
see figure 1
Applies to D
Applies to D
Applies to D
-7V
≤
V
O
≤
+12V
-7V
≤
V
O
≤
+12V
2.0
0.8
±10
35
35
250
250
5
30
30
5
15
40
60
60
Mbps
ns
ns
ns
ns
t
PLH
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
see figures 3 and 6
t
PHL
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
see figures 3 and 6
see figures 3 and 6,
t
SKEW
= | t
DPLH
- t
DPHL
|
From 10% to 90%; R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF;
see figures 3 and 6
SP490 RECEIVER
DC Characteristics
Differential Input Threshold
Input Hysteresis
Output Voltage High
Output Voltage Low
Input Resistance
Input Current (A, B); V
IN
= 12V
Input Current (A, B); V
IN
= -7V
Short-Circuit Current
0.2
70
3.5
+0.2
0.4
12
15
±1.0
-0.8
85
Volts
mV
Volts
Volts
kΩ
mA
mA
mA
-7V
≤
V
CM
≤
12V
V
CM
= 0V
I
O
= -4mA, V
ID
= +200mV
I
O
= +4mA, V
ID
= -200mV
-7V
≤
V
CM
≤
12V
V
IN
= 12V
V
IN
= -7V
0V
≤
V
O
≤
V
CC
Date: 02/24/05
SP490/491 Full Duplex RS-485 Transceivers
© Copyright 2005 Sipex Corporation
2
ELECTRICAL CHARACTERISTICS
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
SP490 RECEIVER
AC Characteristics
Maximum Data Rate
Receiver Input to Output
Receiver Input to Output
Diff. Receiver Skew It
PLH
-t
PHL
I
POWER REQUIREMENTS
Supply Voltage
Supply Current
ENVIRONMENTAL AND
MECHANICAL
Operating Temperature
Commercial (_C_)
Industrial (_E_)
Storage Temperature
Package
Plastic DIP (_S_)
NSOIC (_N)
MIN.
TYP.
MAX.
UNITS
CONDITIONS
5
90
90
13
150
150
Mbps
ns
ns
ns
t
PLH
; R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF;
Figures 3 & 8
t
PHL
; R
DIFF
= 54Ω,
C
L1
= C
L2 =
100pF;
Figures 3 & 8
R
DIFF
= 54Ω; C
L1
= C
L2
= 100pF;
Figures 3 & 8
+4.75
900
+5.25
Volts
µA
0
-40
-65
+70
+85
+150
°C
°C
°C
A
R
V
OD
R
B
V
OC
Receiver
Output
C
RL
Test Point
S
1
1K
S
2
1K
V
CC
Figure 1. Driver DC Test Load Circuit
Figure 2. Receiver Timing Test Load Circuit
3V
DE
DI
A
B
C
L2
R
DIFF
C
L1
A
RO
B
15pF
Output
Under
Test
500
C
L
S
1
V
CC
S
2
Figure 3. Driver/Receiver Timing Test Circuit
Figure 4. Driver Timing Test Load #2 Circuit
Date: 02/24/05
SP490/491 Full Duplex RS-485 Transceivers
© Copyright 2005 Sipex Corporation
3
+3V
DI
0V
DRIVER
OUTPUT
B
A
f = 1MHz; t
R
< 10ns; t
F
< 10ns
1.5V
t
PLH
V
O
1/2V
O
t
DPLH
t
DPHL
t
PHL
1/2V
O
1.5V
DIFFERENTIAL V
O
+
OUTPUT 0V
V
A
– V
B
V
O
–
t
SKEW =
| t
DPLH -
t
DPHL
|
Figure 6. Driver Propagation Delays
t
R
t
F
+3V
DE
0V
5V
A, B
V
OL
V
OH
A, B
0V
f = 1MHz; t
R
< 10ns; t
F
< 10ns
1.5V
t
ZL
2.3V
Output normally LOW
1.5V
t
LZ
0.5V
0.5V
t
HZ
2.3V
t
ZH
Output normally HIGH
Figure 7. Driver Enable and Disable Times
V
0D2
+
A–B
V
0D2
–
V
OH
R
V
OL
t
PHL
0V
INPUT
0V
1.5V
OUTPUT
1.5V
t
PLH
f = 1MHz; t
R
< 10ns; t
F
< 10ns
t
SKEW =
| t
PHL -
t
PLH
|
Figure 8. Receiver Propagation Delays
Date: 02/24/05
SP490/491 Full Duplex RS-485 Transceivers
© Copyright 2005 Sipex Corporation
4
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
CC
............................................................................................................................+7V
Input Voltages
Logic...................................................-0.5V to (V
CC
+0.5V)
Drivers................................................-0.5V to (V
CC
+0.5V)
Receivers..................................................................±14V
Output Voltages
Logic...................................................-0.5V to (V
CC
+0.5V)
Drivers......................................................................±14V
Receivers...........................................-0.5V to (V
CC
+0.5V)
Storage Temperature......................................................-65˚C to +150
Power Dissipation.....................................................................1000mW
ELECTRICAL CHARACTERISTICS
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
SP491 DRIVER
DC Characteristics
Differential Output Voltage
Differential Output Voltage
Differential Output Voltage
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
Driver Common-Mode
Output Voltage
Input High Voltage
Input Low Voltage
Input Current
Driver Short-Circuit Current
V
OUT
= HIGH
V
OUT
= LOW
SP491 DRIVER
AC Characteristics
Maximum Data Rate
Driver Input to Output
Driver Input to Output
Driver Skew
Driver Rise or Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
MIN.
TYP.
MAX.
UNITS
CONDITIONS
GND
2
1.5
V
CC
V
CC
V
CC
0.2
3
Volts
Volts
Volts
Volts
Volts
Volts
Volts
µA
mA
mA
Unloaded; R =
∞
;
see figure 1
With Load; R = 50Ω; (RS422);
see figure 1
With Load; R = 27Ω; (RS485);
see figure 1
R = 27Ω or R = 50Ω;
see figure 1
R = 27Ω or R = 50Ω;
see figure 1
Applies to D, REB, DE
Applies to D, REB, DE
Applies to D, REB, DE
-7V
≤
V
O
≤
12V
-7V
≤
V
O
≤
12V
2.0
0.8
±10
35
35
250
250
5
20
20
30
30
5
60
60
10
40
70
70
70
70
Mbps
ns
ns
ns
ns
ns
ns
ns
ns
3
15
40
40
40
40
REB = 5V, DE = 5V
t
PLH
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
see figures 3 and 6
t
PHL
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
see figures 3 and 6
see figures 3 and 6,
t
SKEW
= | t
DPLH
- t
DPHL
|
From 10% to 90%; R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF;
see figures 3 and 6
C
L1
= C
L2
= 100pF;
see figures
4 and 7;
S
2
closed
C
L1
= C
L2
= 100pF;
see figures
4 and 7;
S
1
closed
C
L1
= C
L2
= 100pF;
see figures
4 and 7;
S
1
closed
C
L1
= C
L2
= 100pF;
see figures
4 and 7;
S
2
closed
Date: 02/24/05
SP490/491 Full Duplex RS-485 Transceivers
© Copyright 2005 Sipex Corporation
5
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