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
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.
RO 1
RE 2
DE 3
DI 4
R
8 Vcc
7 B
6 A
D
SP481, SP483, and SP485
5 GND
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
© Copyright 2002 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
............................................................................................................±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.......................................................-65˚C to +150˚C
Power Dissipation...........................................................................500mW
SPECIFICATIONS
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
SP481/SP483/SP485 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
SP481/SP485 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 DE, DI, RE
Applies to DE, DI, RE
Applies to DE, DI, RE
-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
RE = 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
L
= 100pF;
see figures 4 & 7;
S
2
closed
C
L
= 100pF;
see figures 4 & 7;
S
1
closed
C
L
= 15pF;
see figures 2 & 9;
S
1
closed
C
L
= 15pF;
see figures 2 & 9;
S
2
closed
SP481/SP483/SP485 RECEIVER
DC Characteristics
Differential Input Threshold
-0.2
Input Hysteresis
Output Voltage High
3.5
Output Voltage Low
Three-State (High Impedance)
Output Current
Input Resistance
12
Input Current (A, B); V
IN
= 12V
Input Current (A, B); V
IN
= -7V
Short-Circuit Current
7
+0.2
10
0.4
±1
15
+1.0
-0.8
95
Volts
mV
Volts
Volts
µA
kΩ
mA
mA
mA
-7V
≤
V
CM
≤
+12V
V
CM
= 0V
I
O
= -4mA, V
ID
= +200mV
I
O
= +4mA, V
ID
= -200mV
0.4V
≤
V
O
≤
2.4V; RE = 5V
-7V
≤
V
CM
≤
+12V
DE = 0V, V
CC
= 0V or 5.25V, V
IN
= 12V
DE = 0V, V
CC
= 0V or 5.25V, V
IN
= -7V
0V
≤
V
CM
≤
V
CC
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
© Copyright 2002 Sipex Corporation
2
SPECIFICATIONS
(continued)
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
SP481/SP485 RECEIVER
AC Characteristics
Maximum Data Rate
Receiver Input to Output
Receiver Input to Output
Diff. Receiver Skew It
PLH
-t
PHL
I
Receiver Enable to
Output Low
Receiver Enable to
Output High
Receiver Disable from Low
Receiver Disable from High
SP481
Shutdown Timing
Time to Shutdown
Driver Enable from Shutdown
to Output High
Driver Enable from Shutdown
to Output Low
Receiver Enable from
Shutdown to Output High
Receiver Enable from
Shutdown to Output Low
POWER REQUIREMENTS
Supply Voltage
Supply Current
SP481/485
No Load
SP483
No Load
SP481/SP483
Shutdown Mode
ENVIRONMENTAL AND
MECHANICAL
Operating Temperature
Commercial (_C_)
Industrial (_E_)
Storage Temperature
Package
Plastic DIP (_S)
NSOIC (_N)
MIN.
TYP.
MAX.
UNITS
CONDITIONS
5
60
60
90
90
13
20
20
20
20
200
200
Mbps
ns
ns
ns
RE = 0V, DE = 0V
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
C
RL
= 15pF;
Figures 2 & 9;
S
1
closed
C
RL
= 15pF;
Figures 2 & 9;
S
2
closed
C
RL
= 15pF;
Figures 2 & 9;
S
1
closed
C
RL
= 15pF;
Figures 2 & 9;
S
2
closed
50
50
50
50
ns
ns
ns
ns
50
200
40
40
300
300
600
100
100
1000
1000
ns
ns
ns
ns
ns
RE = 5V, DE = 0V
C
L
= 100pF;
See figures 4 & 7;
S
2
closed
C
L
= 100pF;
See figures 4 & 7;
S
1
closed
C
L
= 15pF;
See figures 2 & 9;
S
2
closed
C
L
= 15pF;
See figures 2 & 9;
S
1
closed
+4.75
900
600
+5.25
Volts
µA
µA
µA
µA
RE, DI = 0V or V
CC
; DE = V
CC
RE = 0V, DI = 0V or 5V; DE = 0V
RE, DI = 0V or V
CC
; DE = V
CC
RE=0V, DI = 0V or 5V; DE = 0V
DE = 0V, RE=V
CC
10
µA
0
-40
-65
+70
+85
+150
°C
°C
°C
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
© Copyright 2002 Sipex Corporation
3
SP483 AC SPECIFICATIONS
T
MIN
to T
MAX
and V
CC
= 5V
±
5% unless otherwise noted.
PARAMETERS
SP483 DRIVER
AC Characteristics
Maximum Data Rate
Driver Input to Output
Driver Skew
Driver Rise and Fall Time
MIN.
TYP.
MAX.
UNITS
CONDITIONS
250
250
250
800
800
100
2000
2000
800
2000
2000
2000
3000
3000
kbps
ns
ns
ns
ns
ns
ns
ns
ns
t
PLH
; R
DIFF
= 54Ω, C
L1
= C
L2 =
100pF;
see figures 3 & 6
t
PHL
; R
DIFF
= 54Ω, C
L1
= C
L2 =
100pF;
see figures 3 & 6
see figures 3 & 6,
t
SKEW
= |t
DPLH
- t
DPHL
|
250
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
SP483 RECEIVER
AC Characteristics
Maximum Data Rate
Receiver Input to Output
Diff. Receiver Skew It
PLH
-t
PHL
I
Receiver Enable to
Output Low
Receiver Enable to
Output High
Receiver Disable from Low
Receiver Disable from High
SP483
Shutdown Timing
Time to Shutdown
Driver Enable from Shutdown
to Output High
Driver Enable from Shutdown
to Output Low
Receiver Enable from
Shutdown to Output High
Receiver Enable from
Shutdown to Output Low
250
250
100
20
20
20
20
250
250
300
300
From 10% to 90%; R
DIFF
= 54Ω,
C
L1
= C
L2
= 100pF,
see figures 3 & 6
C
L
= 100pF;
See figures 4 & 7;
S
2
closed
C
L
= 100pF;
See figures 4 & 7;
S
1
closed
C
L
= 15pF;
See figures 4 & 7;
S
1
closed
C
L
= 15pF;
See figures 4 & 7;
S
2
closed
2000
kbps
ns
ns
t
PLH
; R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
Figures 3 & 8
R
DIFF
= 54Ω, C
L1
= C
L2
= 100pF;
Figures 3 & 8
C
RL
= 15pF;
Figures 2 & 9;
S
1
closed
C
RL
= 15pF;
Figures 2 & 9;
S
2
closed
C
RL
= 15pF;
Figures 2 & 9;
S
1
closed
C
RL
= 15pF;
Figures 2 & 9;
S
2
closed
50
50
50
50
ns
ns
ns
ns
50
200
600
2000
2000
2500
2500
ns
ns
ns
ns
ns
RE = 5V, DE = 0V
C
L
= 100pF;
See figures 4 & 7;
S
2
closed
C
L
= 100pF;
See figures 4 & 7;
S
1
closed
C
L
= 15pF;
See figures 4 & 7;
S
2
closed
C
L
= 15pF;
See figures 4 & 7;
S
1
closed
RO 1
R
8
V
CC
PIN FUNCTION
Pin# Name Description
1
2
3
RO
RE
DE
DI
GND
A
B
Vcc
Receiver Output.
Receiver Output Enable
Active LOW.
Driver Output Enable
Active HIGH.
Driver Input.
Ground Connection.
Driver Output/Receiver Input
Non-inverting.
Driver Output/Receiver Input
Inverting.
Positive Supply 4.75V<Vcc< 5.25V.
© Copyright 2002 Sipex Corporation
RE 2
7
B
DE 3
6
A
D
DI 4
SP485
Top View
5
GND
4
5
6
7
8
SP481, SP483, SP485
Pinout (Top View)
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
4
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 54Ω 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.
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 15kΩ (12kΩ 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 1µA.
Rev. 07/16/02
SP481/483/485 Low Power Half-Duplex RS485 Transceivers
© Copyright 2002 Sipex Corporation
5
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