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
6
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
SP491 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
Three State (high impedance)
Output Current
1
A
0.4V
V
O
2.4V; REB = 5V
Input Resistance
12
15
k
-7V
V
CM
12V
Input Current (A, B); V
IN
= 12V
1.0
mA
DE = 0V, V
CC
= 0V or 5.25V, V
IN
= 12V
Input Current (A, B); V
IN
= -7V
-0.8
mA
DE = 0V, V
CC
= 0V or 5.25V, V
IN
= -7V
Short-Circuit Current
7
85
mA
0V
V
O
V
CC
SP491 RECEIVER
DC Characteristics
Maximum Data Rate
5
Mbps
REB = 0V
Receiver Input to Output
60
90
150
ns
t
PLH
; R
DIFF
= 54
,
C
L1
= C
L2
=
100pF;
Figures 3 & 8
Receiver Input to Output
60
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
Receiver Enable to Output Low
20
50
ns
C
RL
= 15pF; Figures 2 and 9; S
1
closed
Receiver Enable to Output High
20
50
ns
C
RL
= 15pF; Figures 2 and 9; S
2
closed
Receiver Disable from Low
20
50
ns
C
RL
= 15pF; Figures 2 and 9; S
1
closed
Receiver Disable from High
20
50
ns
C
RL
= 15pF; Figures 2 and 9; S
2
closed
POWER REQUIREMENTS
Supply Voltage
+4.75
+5.25
Volts
Supply Current
600
A
REB, D = 0V or V
CC
; DE = V
CC
SP491 ENVIRONMENTAL
+3V
0V
RE
5V
R
0V
1.5V
1.5V
t
ZL
t
ZH
f = 1MHz; t
R
< 10ns; t
F
< 10ns
R
1.5V
1.5V
t
LZ
t
HZ
0.5V
0.5V
Output normally LOW
Output normally HIGH
V
IL
V
IH
Figure 9. Receiver Enable and Disable Times
AND 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
7
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
DESCRIPTION
The SP490 and SP491 are full-duplex differential
transceivers that meet the requirements of
RS-485 and RS-422. Fabricated with a Sipex
proprietary BiCMOS process, both products
require a fraction of the power of older bipolar
designs.
The RS-485 standard is ideal for multi-drop
applications or for long-distance interfaces.
RS-485 allows up to 32 drivers and 32 receivers
to be connected to a data bus, making it an ideal
choice for multi-drop applications. Since the
cabling can be as long as 4,000 feet, RS-485
transceivers are equipped with a wide (-7V to
+12V) common mode range to accommodate
ground potential differences. Because RS-485
is a differential interface, data is virtually
immune to noise in the transmission line.
Driver...
The drivers for both the SP490 and SP491 have
differential outputs. The typical voltage output
swing with no load will be 0 volts to +5 volts.
With worst case loading of 54
across the
differential outputs, the driver can maintain
greater than 1.5V voltage levels.
The driver of the SP491 has a driver enable
control line which is active high. A logic high
on DE (pin 4) of the SP491 will enable
the differential driver outputs. A logic low
on DE (pin 4) of the SP491 will tri-state the
driver outputs. The SP490 does not have a
driver enable.
Receiver...
The receivers for both the SP490 and SP491
have differential inputs with an input sensitivity
as low as
200mV. Input impedance of the
receivers is typically 15K
(12K minimum).
A wide common mode range of -7V to +12V
allows for large ground potential differences
between systems. The receivers for both the
SP490 and SP491 are equipped with the
fail-safe feature. Fail-safe guarantees that
the receiver output will be in a high state when
the input is left unconnected.
The receiver of the SP491 has a receiver
enable control line which is active low. A logic
low on REB (pin 3) of the SP491 will enable
the differential receiver. A logic high on REB
(pin 3) of the SP491 will tri-state the receiver.
8
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
SEE VIEW C
TOP VIEW
8 PIN NSOIC
1
1.65
DIMENSIONS
Minimum/Maximum
(mm)
8 Pin NSOIC
(JEDEC MS-012,
AA - VARIATION)
COMMON HEIGHT DIMENSION
A
A1
A2
b
c
L
e
E1
E
L2
L1
1.35
4.90 BSC
0.40
0.31
0.51
SYMBOL
MIN NOM MAX
0.10
-
0.25
D
1.75
1.25
0.17
0.25
6.00 BSC
3.90 BSC
1.27 BSC
1.27
1.04 REF
0.25 BSC
0
5
8
15
-
-
-
-
-
-
-
e
E
E/2
E1
INDEX AREA
(D/2 X E1/2)
E1/2
D
b
1
L1
L
1
1
Seating Plane
Gauge Plane
L2
VIEW C
A
A2
A1
SEATING PLANE
SIDE VIEW
c
WITH PLATING
BASE METAL
b
CONTACT AREA
PACKAGE: 8 PIN NSOIC
9
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
14 PIN NSOIC
1
1.65
DIMENSIONS
Minimum/Maximum
(mm)
14 Pin NSOIC
(JEDEC MS-012,
AB - VARIATION)
COMMON HEIGHT DIMENSION
A
A1
A2
b
c
L
e
E1
E
L2
L1
1.35
8.65 BSC
0.40
0.31
0.51
SYMBOL
MIN NOM MAX
0.10
-
0.25
D
1.75
1.25
0.17
0.25
6.00 BSC
3.90 BSC
1.27 BSC
1.27
1.04 REF
0.25 BSC
0
5
8
15
-
-
-
-
-
-
-
CONTACT AREA
SEE VIEW C
TOP VIEW
c
WITH PLATING
BASE METAL
b
A
A2
A1
SIDE VIEW
e
E
E/2
E1
b
B
INDEX AREA
(D/2 X E1/2)
E1/2
D
1
L1
L
1
1
Seating Plane
Gauge Plane
L2
VIEW C
PACKAGE: 8 PIN NSOIC
10
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
N
1 2 3
INDEX
AREA
eA
eB
E
- - .210
.015
-
Dimensions in inches
8 PIN PDIP
JEDEC MS-001
(BA) Variation
.115 .130 .195
.014 .018 .022
.045 .060 .070
.240 .250 .280
A
A1
A2
b
c
D1
E
E1
e
eA
eB
.115 .130 .150
L
MIN NOM MAX
b2
b3
.030 .039 .045
D
.008
.010
.014
.355
.365
.400
.005
.300
.310
.325
.100 BSC
.300 BSC
.430
D1
-
-
-
-
-
C
b
N/2
8 pin PDIP
E
E1
D
A
L
A2
A1
b
b2
e
b3
c
PACKAGE: 8 PIN NSOIC
11
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
N
1 2 3
INDEX
AREA
eA
eB
E
C
b
- - .210
.015
-
Dimensions in inches
14 PIN PDIP
JEDEC MS-001
(AA) Variation
.115 .130 .195
.014 .018 .022
.045 .060 .070
.240 .250 .280
A
A1
A2
b
c
D1
E
E1
e
eA
eB
.115 .130 .150
L
MIN NOM MAX
b2
b3
.030 .039 .045
D
.008
.010
.014
.735
.750
.775
.005
.300
.310
.325
.100 BSC
.300 BSC
.430
D1
-
-
-
-
-
N/2
14 pin PDIP
E
E1
D
A
L
A2
A1
b
b2
e
b3
c
PACKAGE: 8 PIN NSOIC
12
Date: 05/10/04
SP490/491 Full Duplex RS-485 Transceivers
Copyright 2004 Sipex Corporation
Model
Temperature Range
Package
SP490CN. ..................................................................................... 0C to +70C ............................................................................... 8-Pin NSOIC
SP490CN/TR ................................................................................ 0C to +70C ............................................................................... 8-Pin NSOIC
SP490CS ...................................................................................... 0C to +70C ................................................................................ 8-Pin PDIP
SP490EN ..................................................................................... -40C to +85C ............................................................................. 8-Pin NSOIC
SP490EN/TR ............................................................................... -40C to +85C ............................................................................. 8-Pin NSOIC
SP490ES ..................................................................................... -40C to +85C .............................................................................. 8-Pin PDIP
SP491CN ...................................................................................... 0C to +70C .............................................................................. 14-Pin NSOIC
SP491CN/TR ................................................................................ 0C to +70C .............................................................................. 14-Pin NSOIC
SP491CS ...................................................................................... 0C to +70C ............................................................................... 14-Pin PDIP
SP491EN ..................................................................................... -40C to +85C ............................................................................ 14-Pin NSOIC
SP491EN/TR ............................................................................... -40C to +85C ............................................................................ 14-Pin NSOIC
SP491ES ..................................................................................... -40C to +85C ............................................................................. 14-Pin PDIP
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the
application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.
Corporation
ANALOG EXCELLENCE
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
/TR = Tape and Reel
Pack quantity is 2500 for NSOIC.
Please consult factory for pricing and availability of various package and temperature options or price and availability of tape-
on-reel.
ORDERING INFORMATION
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