1
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
SP490/SP491
Full Duplex RS-485 Transceivers
+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)
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.
6
1
2
3
4
5
7
8
Vcc
GND
R
D
A
B
Z
Y
R
D
9
10
11
12
13
14
NC
REB
DE
GND
NC
NC
1
2
3
4
5
6
7
8
R
D
Vcc
GND
R
D
A
B
Z
Y
SP490
SP491
DESCRIPTION
BLOCK DIAGRAMS
2
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 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
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....................................................-65C to +150
Power Dissipation.....................................................................1000mW
T
MIN
to T
MAX
and V
CC
= 5V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP490 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
; (RS422);
see figure 1
Differential Output Voltage
1.5
V
CC
Volts
With Load; R = 27
; (RS485); see figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
0.2
Volts
R = 27
or R = 50
; see figure 1
Driver Common-Mode
Output Voltage
3
Volts
R = 27
or R = 50
; see figure 1
Input High Voltage
2.0
Volts
Applies to D
Input Low Voltage
0.8
Volts
Applies to D
Input Current
10
A
Applies to D
Driver Short-Circuit Current
V
OUT
= HIGH
35
250
mA
-7V
V
O
+12V
V
OUT
= LOW
35
250
mA
-7V
V
O
+12V
SP490 DRIVER
AC Characteristics
Maximum Data Rate
5
Mbps
Driver Input to Output
30
60
ns
t
PLH
; R
DIFF
= 54
, C
L1
= C
L2
= 100pF;
see figures 3 and 6
Driver Input to Output
30
60
ns
t
PHL
; R
DIFF
= 54
, C
L1
= C
L2
= 100pF;
see figures 3 and 6
Driver Skew
5
ns
see figures 3 and 6,
t
SKEW
= | t
DPLH
- t
DPHL
|
Driver Rise or Fall Time
15
40
ns
From 10% to 90%; R
DIFF
= 54
,
C
L1
= C
L2
= 100pF; see figures 3 and 6
SP490 RECEIVER
DC Characteristics
Differential Input Threshold
0.2
+0.2
Volts
-7V
V
CM
12V
Input Hysteresis
70
mV
V
CM
= 0V
Output Voltage High
3.5
Volts
I
O
= -4mA, V
ID
= +200mV
Output Voltage Low
0.4
Volts
I
O
= +4mA, V
ID
= -200mV
Input Resistance
12
15
k
-7V
V
CM
12V
Input Current (A, B); V
IN
= 12V
1.0
mA
V
IN
= 12V
Input Current (A, B); V
IN
= -7V
-0.8
mA
V
IN
= -7V
Short-Circuit Current
85
mA
0V
V
O
V
CC
ELECTRICAL CHARACTERISTICS
3
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
T
MIN
to T
MAX
and V
CC
= 5V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP490 RECEIVER
AC Characteristics
Maximum Data Rate
5
Mbps
Receiver Input to Output
90
150
ns
t
PLH
; R
DIFF
= 54
,
C
L1
= C
L2
=
100pF;
Figures 3 & 8
Receiver Input to Output
90
150
ns
t
PHL
; R
DIFF
= 54
,
C
L1
= C
L2
=
100pF;
Figures 3 & 8
Diff. Receiver Skew It
PLH
-t
PHL
I
13
ns
R
DIFF
= 54
; C
L1
= C
L2
= 100pF;
Figures 3 & 8
POWER REQUIREMENTS
Supply Voltage
+4.75
+5.25
Volts
Supply Current
900
A
ENVIRONMENTAL AND
C
L1
15pF
RO
A
B
A
B
DI
DE
3V
C
L2
R
DIFF
500
C
L
Output
Under
Test
S
1
S
2
V
CC
Figure 3. Driver/Receiver Timing Test Circuit
Figure 4. Driver Timing Test Load #2 Circuit
A
B
R
R
V
OD
V
OC
1K
1K
C
RL
Receiver
Output
S
1
S
2
Test Point
V
CC
Figure 1. Driver DC Test Load Circuit
Figure 2. Receiver Timing Test Load Circuit
MECHANICAL
Operating Temperature
Commercial (_C_)
0
+70
C
Industrial (_E_)
-40
+85
C
Storage Temperature
-65
+150
C
Package
Plastic DIP (_S_)
NSOIC (_N)
ELECTRICAL CHARACTERISTICS
4
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
Figure 6. Driver Propagation Delays
+3V
0V
DE
5V
V
OL
A, B
0V
1.5V
1.5V
t
ZL
t
ZH
f = 1MHz; t
R
< 10ns; t
F
< 10ns
V
OH
A, B
2.3V
2.3V
t
LZ
t
HZ
0.5V
0.5V
Output normally LOW
Output normally HIGH
Figure 7. Driver Enable and Disable Times
Figure 8. Receiver Propagation Delays
+3V
+3V
0V
DI
DI
B
A
DRIVER
DRIVER
OUTPUT
OUTPUT
V
O
+
DIFFERENTIAL
DIFFERENTIAL
OUTPUT
OUTPUT
V
A
V
B
0V
V
O
1.5V
1.5V
t
PLH
PLH
t
R
t
F
f = 1MHz; t
f = 1MHz; t
R
< 10ns; t
< 10ns; t
F
F
< 10ns
< 10ns
V
O
1/2V
1/2V
O
1/2V
O
t
PHL
PHL
t
DPLH
DPLH
t
DPHL
DPHL
t
SKEW =
SKEW =
|
t
DPLH -
DPLH -
t
DPHL
DPHL
|
V
OH
V
OL
R
1.5V
1.5V
t
PHL
f = 1MHz; t
R
< 10ns; t
F
< 10ns
OUTPUT
V
0D2
+
V
0D2
A B
0V
0V
t
PLH
INPUT
t
SKEW =
|
t
PHL -
t
PLH
|
5
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 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
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......................................................-65C to +150
Power Dissipation.....................................................................1000mW
T
MIN
to T
MAX
and V
CC
= 5V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP491 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
; (RS422);
see figure 1
Differential Output Voltage
1.5
V
CC
Volts
With Load; R = 27
; (RS485); see figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
0.2
Volts
R = 27
or R = 50
; see figure 1
Driver Common-Mode
Output Voltage
3
Volts
R = 27
or R = 50
; 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
A
Applies to D, REB, DE
Driver Short-Circuit Current
V
OUT
= HIGH
35
250
mA
-7V
V
O
12V
V
OUT
= LOW
35
250
mA
-7V
V
O
12V
SP491 DRIVER
AC Characteristics
Maximum Data Rate
5
Mbps
REB = 5V, DE = 5V
Driver Input to Output
20
30
60
ns
t
PLH
; R
DIFF
= 54
, C
L1
= C
L2
= 100pF;
see figures 3 and 6
Driver Input to Output
20
30
60
ns
t
PHL
; R
DIFF
= 54
, C
L1
= C
L2
= 100pF;
see figures 3 and 6
Driver Skew
5
10
ns
see figures 3 and 6,
t
SKEW
= | t
DPLH
- t
DPHL
|
Driver Rise or Fall Time
3
15
40
ns
From 10% to 90%; R
DIFF
= 54
,
C
L1
= C
L2
= 100pF; see figures 3 and 6
Driver Enable to Output High
40
70
ns
C
L1
= C
L2
= 100pF; see figures
4 and 7;
S
2
closed
Driver Enable to Output Low
40
70
ns
C
L1
= C
L2
= 100pF; see figures
4 and 7;
S
1
closed
Driver Disable Time from Low
40
70
ns
C
L1
= C
L2
= 100pF; see figures
4 and 7;
S
1
closed
Driver Disable Time from High
40
70
ns
C
L1
= C
L2
= 100pF; see figures
4 and 7;
S
2
closed
ELECTRICAL CHARACTERISTICS
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