1
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
SP481/SP483/SP485
Low Power Half-Duplex RS-485 Transceivers
+5V Only
Low Power BiCMOS
Driver/Receiver Enable
Slew Rate Limited Driver for
Low EMI (SP483)
Low Power Shutdown Mode (SP481
and SP483)
RS-485 and RS-422 Drivers/Receivers
8
7
6
5
1
2
3
4
Vcc
B
A
GND
D
R
RO
RE
DE
DI
SP481, SP483, and SP485
RE
DESCRIPTION
The SP481, SP483, and the SP485 are a family of half-duplex transceivers that meet the
requirements of RS-485 and RS-422. Their BiCMOS design allows low power operation
without sacrificing performance. The SP481 and SP485 meet the requirements of RS-485
and RS-422 up to 5Mbps. Additionally, the SP481 is equipped with a low power Shutdown
mode. The SP483 is internally slew rate limited to reduce EMI and can meet the requirements
of RS-485 and RS-422 up to 250kbps. The SP483 is also equipped with a low power
Shutdown mode.
2
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
Copyright 2002 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
............................................................................................................
12V
Input Voltages
Logic........................................................-0.3V to (V
CC
+0.5V)
Drivers..................................................-0.3V to (V
CC
+0.5V)
Receivers.................................................................
15V
Output Voltages
Logic........................................................-0.3V to (V
CC
+0.5V)
Drivers......................................................................
15V
Receivers............................................-0.3V to (V
CC
+0.5V)
Storage Temperature.......................................................-65C to +150C
Power Dissipation...........................................................................500mW
SPECIFICATIONS
T
MIN
to T
MAX
and V
CC
= 5V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP481/SP483/SP485 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 DE, DI, RE
Input Low Voltage
0.8
Volts
Applies to DE, DI, RE
Input Current
10
A
Applies to DE, DI, RE
Driver Short-Circuit Current
V
OUT
= HIGH
35
250
mA
-7V
V
O
+12V
V
OUT
= LOW
35
250
mA
-7V
V
O
+12V
SP481/SP485 DRIVER
AC Characteristics
Maximum Data Rate
5
Mbps
RE = 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
L
= 100pF;
see figures 4 & 7; S
2
closed
Driver Enable to Output Low
40
70
ns
C
L
= 100pF;
see figures 4 & 7; S
1
closed
Driver Disable Time from Low
40
70
ns
C
L
= 15pF;
see figures 2 & 9; S
1
closed
Driver Disable Time from High
40
70
ns
C
L
= 15pF;
see figures 2 & 9; S
2
closed
SP481/SP483/SP485 RECEIVER
DC Characteristics
Differential Input Threshold
-0.2
+0.2
Volts
-7V
V
CM
+12V
Input Hysteresis
10
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; RE = 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
95
mA
0V
V
CM
V
CC
3
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
MECHANICAL
Operating Temperature
Commercial (_C_)
0
+70
C
Industrial (_E_)
-40
+85
C
Storage Temperature
-65
+150
C
Package
Plastic DIP (_S)
NSOIC (_N)
SPECIFICATIONS (continued)
T
MIN
to T
MAX
and V
CC
= 5V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP481/SP485 RECEIVER
AC Characteristics
Maximum Data Rate
5
Mbps
RE = 0V, DE = 0V
Receiver Input to Output
60
90
200
ns
t
PLH
; R
DIFF
= 54
,
C
L1
= C
L2
=
100pF;
Figures 3 & 8
Receiver Input to Output
60
90
200
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 & 9; S
1
closed
Receiver Enable to
Output High
20
50
ns
C
RL
= 15pF;
Figures 2 & 9; S
2
closed
Receiver Disable from Low
20
50
ns
C
RL
= 15pF;
Figures 2 & 9; S
1
closed
Receiver Disable from High
20
50
ns
C
RL
= 15pF;
Figures 2 & 9; S
2
closed
SP481
Shutdown Timing
Time to Shutdown
50
200
600
ns
RE = 5V, DE = 0V
Driver Enable from Shutdown
to Output High
40
100
ns
C
L
= 100pF;
See figures 4 & 7; S
2
closed
Driver Enable from Shutdown
to Output Low
40
100
ns
C
L
= 100pF;
See figures 4 & 7; S
1
closed
Receiver Enable from
Shutdown to Output High
300
1000
ns
C
L
= 15pF;
See figures 2 & 9; S
2
closed
Receiver Enable from
Shutdown to Output Low
300
1000
ns
C
L
= 15pF;
See figures 2 & 9; S
1
closed
POWER REQUIREMENTS
Supply Voltage
+4.75
+5.25
Volts
Supply Current
SP481/485
No Load
900
A
RE, DI = 0V or V
CC
; DE = V
CC
A
RE = 0V, DI = 0V or 5V; DE = 0V
SP483
No Load
600
A
RE, DI = 0V or V
CC
; DE = V
CC
A
RE=0V, DI = 0V or 5V; DE = 0V
SP481/SP483
Shutdown Mode
10
A
DE = 0V, RE=V
CC
ENVIRONMENTAL AND
4
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
PIN FUNCTION
Pin# Name Description
1 RO Receiver Output.
2 RE Receiver Output Enable
Active LOW.
3 DE Driver Output Enable
Active HIGH.
4 DI Driver Input.
5 GND Ground Connection.
6 A Driver Output/Receiver Input
Non-inverting.
7 B Driver Output/Receiver Input
Inverting.
8 Vcc Positive Supply 4.75V<Vcc< 5.25V.
SP481, SP483, SP485
Pinout (Top View)
RO 1
RE 2
DE 3
DI 4
8 V
CC
7 B
6 A
5 GND
D
R
SP485
Top View
SP483 AC SPECIFICATIONS
T
MIN
to T
MAX
and V
CC
= 5V
5% unless otherwise noted.
PARAMETERS
MIN.
TYP.
MAX.
UNITS
CONDITIONS
SP483 DRIVER
AC Characteristics
Maximum Data Rate
250
kbps
Driver Input to Output
250
800
2000
ns
t
PLH
; R
DIFF
= 54
, C
L1
= C
L2
=
100pF;
see figures 3 & 6
Driver Skew
250
800
2000
ns
t
PHL
; R
DIFF
= 54
, C
L1
= C
L2
=
100pF;
see figures 3 & 6
Driver Rise and Fall Time
100
800
ns
see figures 3 & 6,
t
SKEW
= |t
DPLH
- t
DPHL
|
250
2000
ns
From 10% to 90%; R
DIFF
= 54
,
C
L1
= C
L2
= 100pF,
see figures 3 & 6
Driver Enable to Output High
250
2000
ns
C
L
= 100pF;
See figures 4 & 7; S
2
closed
Driver Enable to Output Low
250
2000
ns
C
L
= 100pF;
See figures 4 & 7; S
1
closed
Driver Disable Time from Low
300
3000
ns
C
L
= 15pF;
See figures 4 & 7; S
1
closed
Driver Disable Time from High
300
3000
ns
C
L
= 15pF;
See figures 4 & 7; S
2
closed
SP483 RECEIVER
AC Characteristics
Maximum Data Rate
250
kbps
Receiver Input to Output
250
2000
ns
t
PLH
; R
DIFF
= 54
, C
L1
= C
L2
=
100pF;
Figures 3 & 8
Diff. Receiver Skew It
PLH
-t
PHL
I
100
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 & 9; S
1
closed
Receiver Enable to
Output High
20
50
ns
C
RL
= 15pF;
Figures 2 & 9; S
2
closed
Receiver Disable from Low
20
50
ns
C
RL
= 15pF;
Figures 2 & 9; S
1
closed
Receiver Disable from High
20
50
ns
C
RL
= 15pF;
Figures 2 & 9; S
2
closed
SP483
Shutdown Timing
Time to Shutdown
50
200
600
ns
RE = 5V, DE = 0V
Driver Enable from Shutdown
to Output High
2000
ns
C
L
= 100pF;
See figures 4 & 7; S
2
closed
Driver Enable from Shutdown
to Output Low
2000
ns
C
L
= 100pF;
See figures 4 & 7; S
1
closed
Receiver Enable from
Shutdown to Output High
2500
ns
C
L
= 15pF;
See figures 4 & 7; S
2
closed
Receiver Enable from
Shutdown to Output Low
2500
ns
C
L
= 15pF;
See figures 4 & 7; S
1
closed
5
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
Copyright 2002 Sipex Corporation
Receivers
SP481, SP483, SP485
The SP481, SP483, and SP485 receivers have
differential inputs with an input sensitivity as
low as
200mV. Input impedance of the receiv-
ers is typically 15k
(12k minimum). A wide
common mode range of -7V to +12V allows for
large ground potential differences between
systems. The receivers of the SP481, SP483
and SP485 have a tri-state enable control pin.
A logic LOW on RE (pin 4) will enable the
receiver, a logic HIGH on RE (pin 4) will disable
the receiver.
The receiver for the SP481 and SP485 will
operate up to at least 5Mbps. The SP483 receiver
is rated for data rates up to 250kbps. The receiver
for each of the three devices is 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.
Shutdown Mode
SP481/SP483
The SP481 and SP483 are equipped with a
Shutdown mode. To enable the Shutdown state,
both the driver and receiver must be disabled
simultaneously. A logic LOW on DE (pin 5) and
a logic HIGH on RE (pin 4) will put the SP481
or SP483 into Shutdown mode. In Shutdown,
supply current will drop to typically 1
A.
DESCRIPTION
SP481, SP483, SP485
The SP481, SP483, and SP485 are half-duplex
differential transceivers that meet the require-
ments of RS-485 and RS-422. Fabricated with a
Sipex proprietary BiCMOS process, all three
products require a fraction of the power of older
bipolar designs.
The RS-485 standard is ideal for multi-drop
applications and 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.
Drivers
SP481, SP483, SP485
The driver outputs of the SP481, SP483, and
SP485 are differential outputs meeting the RS-
485 and RS-422 standards. 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 drivers can maintain
greater than 1.5V voltage levels. The drivers of
the SP481, SP483 and SP485 have an enable
control line which is active HIGH. A logic
HIGH on DE (pin 5) will enable the differential
driver outputs. A logic LOW on DE (pin 5) will
tri-state the driver outputs.
The transmitters of the SP481 and SP485 will
operate up to at least 5Mbps. The SP483 has
internally slew rate limited driver outputs to
minimize EMI. The maximum data rate for the
SP483 driver is 250kbps.
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