1
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
Full Duplex RS-485 and RS-422
Transceivers
Operates from a single +3.3V supply
Interoperable with +5.0V logic
Driver/Receiver Tri-state Enable
Lines (SP3491)
-7V to +12V Common-Mode Input
Voltage Range
+200mV Receiver Input Sensitivity
Allows up to 32 transceivers on
the serial bus
Compatibility with LTC490
and SN75179 (SP3490)
Compatibility with LTC491
and SN75180 (SP3491)
SP3490/SP3491
DESCRIPTION
The SP3490 and the SP3491 are +3.3V low power full duplex transceivers that meet the
specifications of the RS-485 and RS-422 serial protocols. These devices are pin-to-pin
compatible with the Sipex SP490 and SP491 devices as well as popular industry standards.
The SP3490 and the SP3491 feature Sipex's BiCMOS process, allowing low power operation
without sacrificing performance. The SP3490 and SP3491 meet the electrical specifications
of RS-485 and RS-422 serial protocols up to 10Mbps under load. The SP3491 is identical to
the SP3490 with the addition of driver and receiver tri-state enable lines.
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
SP3490
SP3491
+3.3V Low Power Full Duplex RS-485
Transceivers with 10Mbps Data Rate
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
2
SPECIFICATIONS
T
AMB
= T
MIN
to T
MAX
and V
CC
= 3.3V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP3490 DRIVER
DC Characteristics
Differential Output Voltage
GND
V
CC
Volts
Unloaded; R =
;
Figure 1
Differential Output Voltage
2
V
CC
Volts
With Load; R = 50
; (RS-422);
Figure 1
Differential Output Voltage
1.5
V
CC
Volts
With Load; R = 27
; (RS-485);
Figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
0.2
Volts
R = 27
or R = 50
;
Figure 1
Driver Common-Mode
Output Voltage
3
Volts
R = 27
or R = 50
;
Figure 1
Input High Voltage
2.0
Volts
Input Low Voltage
0.8
Volts
Input Current
+10
A
Driver Short-Circuit Current
V
OUT
= HIGH
+250
mA
-7V < V
O
< +12V
V
OUT
= LOW
+250
mA
-7V < V
O
< +12V
SP3490 DRIVER
AC Characteristics
Maximum Data Rate
10
Mbps
Driver Input to Output, t
PLH
20
40
60
ns
R=27
,
Figures 2 and 8
Driver Input to Output, t
PHL
20
40
60
ns
R=27
,
Figures 2 and 8
Differential Driver Skew
2
ns
t
PHL
(Y) - t
PLH
(Y) , t
PHL
(Z) - t
PLH
(Z) ,
Figures 2 and 8
Driver Rise or Fall Time
5
20
ns
From 10% to 90%;
Figures 3 and 9
SP3490 RECEIVER
DC Characteristics
Differential Input Threshold
0.2
+0.2
Volts
-7V < V
CM
< 12V
Input Hysteresis
25
mV
V
CM
= 0V
Output Voltage High
V
CC
-0.4
Volts
I
O
= -1.5mA, V
ID
= +200mV
Output Voltage Low
0.4
Volts
I
O
= +2.5mA, 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
60
mA
0V < V
O
< V
CC
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
............................................................................................. +6.0V
Input Voltages
Drivers ............................................................... -0.3V to +6.0V
Receivers .........................................................................
14V
Output Voltages
Drivers ..............................................................................
14V
Receivers .......................................................... -0.3V to +6.0V
Storage Temperature ................................................... -65C to +150
Power Dissipation per Package
8-pin NSOIC (derate 6.90mW/
o
C above +70
o
C) ..................... 600mW
8-pin PDIP (derate 11.8mW/
o
C above +70
o
C) ...................... 1000mW
14-pin NSOIC (derate 8.33mW/
o
C above +70
o
C) ................... 700mW
14-pin PDIP (derate 14.3mW/
o
C above +70
o
C) .................... 1200mW
3
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
SPECIFICATIONS (continued)
T
AMB
= T
MIN
to T
MAX
and V
CC
= 3.3V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP3490 RECEIVER
AC Characteristics
Maximum Data Rate
10
Mbps
Receiver Input to Output, t
PLH
40
70
120
ns
Figures 6 and 11
85
ns
T
AMB
= 25
o
C, V
CC
= 3.3V,
Figures 6 and 11
Receiver Input to Output, t
PHL
40
70
120
ns
Figures 6 and 11
85
ns
T
AMB
= 25
o
C, V
CC
= 3.3V,
Figures 6 and 11
Differential Receiver Skew
4
ns
t
PHL
(A) - t
PLH
(A) , t
PHL
(B) - t
PLH
(B) ,
Figures 6 and 11
POWER REQUIREMENTS
Supply Voltage
+3.0
+3.6
Volts
Supply Current
1000
2000
A
DE = V
CC
800
1500
DE = 0
Figure 4. Driver Enable and Disable Timing Circuit,
Output HIGH
Figure 5. Driver Enable and Disable Timing Circuit,
Output LOW
Figure 1. Driver DC Test Load Circuit
Figure 2. Driver Propagation Delay Test Circuit
GENERATOR
(NOTE 1)
50
V
CC
S1
V
DM
R
L
= 27
OUT
C
L
= 15pF
(NOTE 2)
V
OM
= 1.5V
V
OH
+ V
OL
2
D
GENERATOR
(NOTE 1)
50
S1
R
L
= 110
OUT
C
L
= 50pF
(NOTE 2)
V
OM
= 1.5V
V
OH
+ V
OL
2
D
GENERATOR
(NOTE 1)
50
S1
R
L
= 110
OUT
C
L
= 50pF
(NOTE 2)
D
0V OR 3V
V
CC
R
R
V
OC
D
V
CC
V
OD
Figure 6. Receiver Propagation Delay Test Circuit
GENERATOR
(NOTE 1)
50
1.5V
0V
V
ID
R
OUT
C
L
= 15pF
(NOTE 2)
V
OM
= V
CC
2
GENERATOR
(NOTE 1)
50
C
L
OUT
D
V
CC
R
L
=
60
C
L
= 15pF (NOTE 2)
Figure 3. Driver Differential Output Delay and
Transition Time Circuit
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
4
Figure 7. Receiver Enable and Disable Timing Circuit
Figure 8. Driver Propagation Delay Waveforms
Figure 9. Driver Differential Output Delay and
Transition Time Waveforms
Figure 10. Driver Enable and Disable Timing Waveforms
Figure 11. Receiver Propagation Delay Waveforms
1.5V
-1.5V
S3
V
ID
GENERATOR
(NOTE 1)
50
C
L =
15pF
(NOTE 2)
R
1k
S1
S2
V
CC
0V
V
OH
t
PLH
t
PHL
V
OM
t
PHL
t
PLH
3V
V
OL
V
OH
1.5V
1.5V
INPUT
Y OUTPUT
V
OM
Z OUTPUT
V
OL
V
OM
V
OM
V
OM
= V
OH
+ V
OL
2
1.5V
3V
0V
V
CC
t
RPLH
1.5V
t
RPHL
V
OM
V
OM
0V
1.5V
INPUT
OUTPUT
V
OM
= V
CC
2
IN
1.5V
t
DPLH
1.5V
t
DPHL
3V
0V
OUT
50%
50%
10%
10%
90%
90%
t
R
t
F
2.0V
-2.0V
0V
V
OH
t
PZH
0.25V
t
PHZ
V
OM
t
PZL
t
PLZ
3V
V
OL
V
CC
1.5V
1.5V
DE
OUTPUT
HIGH
V
OM
0.25V
0V
OUTPUT
LOW
V
OM
= V
OH
+ V
OL
2
1.5V
5
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
SPECIFICATIONS
T
AMB
= T
MIN
to T
MAX
and V
CC
= +3.3V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP3491 DRIVER
DC Characteristics
Differential Output Voltage
GND
V
CC
Volts
Unloaded; R =
;
Figure 1
Differential Output Voltage
2
V
CC
Volts
With Load; R = 50
; (RS-422);
Figure 1
Differential Output Voltage
1.5
V
CC
Volts
With Load; R = 27
; (RS-485);
Figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary States
0.2
Volts
R = 27
or R = 50
;
Figure 1
Driver Common-Mode
Output Voltage
3
Volts
R = 27
or R = 50
;
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
+250
mA
-7V < V
O
< +12V
V
OUT
= LOW
+250
mA
-7V < V
O
< +12V
SP3491 DRIVER
AC Characteristics
Maximum Data Rate
10
Mbps
Driver Input to Output, t
PLH
20
40
60
ns
Figures 2 and 8
Driver Input to Output, t
PHL
20
40
60
ns
Figures 2 and 8
Differential Driver Skew
2
ns
t
PHL
(Y) - t
PLH
(Y) , t
PHL
(Z) - t
PLH
(Z) ,
Figures 2 and 8
Driver Rise or Fall Time
5
20
ns
From 10% to 90%;
Figures 3 and 9
Driver Enable to Output HIGH
52
120
ns
Figures 4 and 10
Driver Enable to Output LOW
60
120
ns
Figures 5 and 10
Driver Disable from LOW
40
120
ns
Figures 5 and 10
Driver Disable from HIGH
60
120
ns
Figures 4 and 10
NOTE 1: The input pulse is supplied by a generator with the following characteristics:
PRR=250KHz, 50% duty cycle, t
r
< 6.0ns, Z
0
=50
.
NOTE 2: C
L
includes probe and stray capacitance.
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
6
Receiver Disable from HIGH
65
200
ns
Figures 7 and 12; S
2
closed, S
1
open
POWER REQUIREMENTS
Supply Voltage
+3.0
+3.6
Volts
Supply Current
1000
2000
A
REB, D = 0V or V
CC
; DE = V
CC
800
1500
A
DE=0V
SPECIFICATIONS (continued)
T
AMB
= T
MIN
to T
MAX
and V
CC
= +3.3V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP3491 RECEIVER
DC Characteristics
Differential Input Threshold
-0.2
+0.2
Volts
-7V < V
CM
< 12V
Input Hysteresis
25
mV
V
CM
= 0V
Output Voltage HIGH
V
CC
-0.4
Volts
I
O
= -1.5mA, V
ID
= +200mV
Output Voltage LOW
0.4
Volts
I
O
= +2.5mA, V
ID
= -200mV
Three State (high impedance)
Output Current
+1
A
0V < V
O
< V
CC
; REB = V
CC
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 +3.6V, V
IN
= 12V
Input Current (A, B); V
IN
= -7V
-0.8
mA
DE = 0V, V
CC
= 0V or +3.6V, V
IN
= -7V
Short-Circuit Current
60
mA
0V < V
O
< V
CC
SP3491 RECEIVER
AC Characteristics
Maximum Data Rate
10
Mbps
REB = 0V, DE = V
CC
Receiver Input to Output, t
PLH
40
70
120
ns
Figures 6 & 11
85
ns
T
AMB
= +25
o
C, V
CC
= +3.3V,
Figures 6 and 11
Receiver Input to Output, t
PHL
40
70
120
ns
Figures 6 & 11
85
ns
T
AMB
= +25
o
C, V
CC
= +3.3V,
Figures 6 and 11
Differential Receiver Skew
4
ns
t
PHL
(A) - t
PLH
(A) , t
PHL
(B) - t
PLH
(B) ,
Figures 6 & 11
Receiver Enable to Output LOW
65
150
ns
Figures 7 and 12; S
1
closed, S
2
open
Receiver Enable to Output HIGH
65
150
ns
Figures 7 and 12; S
2
closed, S
1
open
Receiver Disable from LOW
65
200
ns
Figures 7 and 12; S
1
closed, S
2
open
Figure 12. Receiver Enable and Disable Waveforms
3V
0V
t
PRLZ
1.5V
t
PRZL
t
PRSL
1.5V
1.5V
10%
V
CC
REB
OUTPUT
S1 is closed
S2 is open
S3 = -1.5V
V
OL
3V
0V
t
PRHZ
1.5V
t
PRZH
t
PRSH
1.5V
1.5V
10%
0V
V
OH
REB
OUTPUT
S1 is open
S2 is closed
S3 = 1.5V
7
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
Figure 14. Pinout for the SP3491
Figure 13. Pinout for the SP3490
PIN FUNCTION - SP3490
Pin 1 - V
CC
- Positive supply +3.00 < V
CC
< +3.60
Pin 2 - R - Receiver output.
Pin 3 - D - Driver input.
Pin 4 - GND - Ground connection.
Pin 5 - Y - Non-inverting driver output.
Pin 6 - Z - Inverting driver output.
Pin 7 - B - Inverting receiver input.
Pin 8 - A - Non-inverting receiver input.
PIN FUNCTION - SP3491
Pin 1 - NC - No connect.
Pin 2 - R - Receiver output.
Pin 3 - REB - Receiver output enable active LOW.
Pin 4 - DE - Driver output enable active HIGH.
Pin 5 - D - Driver input.
Pin 6 - GND - Ground connection.
Pin 7 - GND - Ground connection.
Pin 8 - NC - No connect.
Pin 9 - Y - Non-inverting driver output.
Pin 10 - Z - Inverting driver output.
Pin 11 - B - Inverting receiver input.
Pin 12 - A - Non-inverting receiver input.
Pin 13 - NC - No connect.
Pin 14 - V
CC
- Positive supply +3.00 < V
CC
< +3.60
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
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
8
DESCRIPTION
The SP3490 and the SP3491 are two members
in the family of +3.3V low power full duplex
transceivers that meet the electrical specifications
of the RS-485 and RS-422 serial protocols.
These devices are pin-to-pin compatible with
the Sipex SP490 and the SP491 devices as well
as popular industry standards. The SP3490 and
the SP3491 feature Sipex's BiCMOS process
allowing low power operation without sacrificing
performance.
Driver
The drivers for both the SP3490 and SP3491
have differential outputs. The typical voltage
output swing with no load will be 0 volts to V
CC.
With a load of 54
across the differential
outputs, the driver maintains greater than 1.5V
voltage levels.
The driver of the SP3491 has a driver enable
control line which is active high. A logic high on
DE (pin 4) of the SP3491 will enable the differ-
ential driver outputs. A logic low on DE (pin 4)
of the SP3491 will tri-state the driver outputs.
The SP3490 does not have a driver enable.
Receiver
The receivers for the SP3490 and SP3491 have
differential inputs with an input sensitivity
as low as
100mV. 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
SP3490 and SP3491 are equipped with a
fail-safe feature that guarantees the receiver
output will be in a high state when the input
is left unconnected.
The receiver of the SP3491 has a receiver enable
control line which is active low. A logic low on
REB (pin 3) of the SP3491 will enable the
differential receiver. A logic high on REB
(pin 3) of the SP3491 will tri-state the receiver.
9
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
D
ALTERNATE
END PINS
(BOTH ENDS)
D1 = 0.005" min.
(0.127 min.)
E
PACKAGE: PLASTIC
DUALINLINE
(NARROW)
DIMENSIONS (Inches)
Minimum/Maximum
(mm)
A = 0.210" max.
(5.334 max).
E1
C
L
A2
A1 = 0.015" min.
(0.381min.)
B
B1
e = 0.100 BSC
(2.540 BSC)
e
A
= 0.300 BSC
(7.620 BSC)
A2
B
B1
C
D
E
E1
L
0.115/0.195
(2.921/4.953)
0.014/0.022
(0.356/0.559)
0.045/0.070
(1.143/1.778)
0.008/0.014
(0.203/0.356)
0.735/0.775
(18.669/19.685)
0.300/0.325
(7.620/8.255)
0.240/0.280
(6.096/7.112)
0.115/0.150
(2.921/3.810)
0/ 15
(0/15)
0.115/0.195
(2.921/4.953)
0.014/0.022
(0.356/0.559)
0.045/0.070
(1.143/1.778)
0.008/0.014
(0.203/0.356)
0.355/0.400
(9.017/10.160)
0.300/0.325
(7.620/8.255)
0.240/0.280
(6.096/7.112)
0.115/0.150
(2.921/3.810)
0/ 15
(0/15)
8PIN
14PIN
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
10
D
E
H
PACKAGE: PLASTIC
SMALL OUTLINE (SOIC)
(NARROW)
DIMENSIONS (Inches)
Minimum/Maximum
(mm)
8PIN
A
A1
L
B
e
h x 45
A
A1
B
D
E
e
H
h
L
0.053/0.069
(1.346/1.748)
0.004/0.010
(0.102/0.249
0.014/0.019
(0.35/0.49)
0.189/0.197
(4.80/5.00)
0.150/0.157
(3.802/3.988)
0.050 BSC
(1.270 BSC)
0.228/0.244
(5.801/6.198)
0.010/0.020
(0.254/0.498)
0.016/0.050
(0.406/1.270)
0/8
(0/8)
14PIN
0.053/0.069
(1.346/1.748)
0.004/0.010
(0.102/0.249)
0.013/0.020
(0.330/0.508)
0.337/0.344
(8.552/8.748)
0.150/0.157
(3.802/3.988)
0.050 BSC
(1.270 BSC)
0.228/0.244
(5.801/6.198)
0.010/0.020
(0.254/0.498)
0.016/0.050
(0.406/1.270)
0/8
(0/8)
11
Rev. 10/11/02
SP3490/3491 Low Power Full-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
ORDERING INFORMATION
Model
Temperature Range
Package
SP3490CN
0C to +70C
8-Pin NSOIC
SP3490CP
0C to +70C
8-Pin DIP
SP3490EN
-40C to +85C
8-Pin NSOIC
SP3490EP
-40C to +85C
8-Pin DIP
SP3491CN
0C to +70C
14-Pin NSOIC
SP3491CP
0C to +70C
14-Pin DIP
SP3491EN.
-40C to +85C
14-Pin NSOIC
SP3491EP
-40C to +85C
14-Pin DIP
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.
Please consult the factory for pricing and availability on a Tape-On-Reel option.
Corporation
Sipex Corporation
Headquarters and
Sales Office
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 934-7500
FAX: (408) 935-7600
Sales Office
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
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