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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_SP485_101_062711
DESCRIPTION
FEATURES
• +5V Only
• Low Power BiCMOS
• Driver / Receiver Enable
• Slew Rate Limited Driver for Low EMI (SP483)
• Low Power Shutdown mode (SP483)
• RS-485 and RS-422 Drivers/Receivers
SP483 / SP485
Low Power Half-Duplex RS-485 Transceivers
The SP483 and SP485 are a family of half-duplex transceivers that meet the specications
of RS-485 and RS-422. Their BiCMOS design allows low power operation without sacricing
performance. The SP485 meets the requirements of RS-485 and RS-422 up to 5Mbps. Ad-
ditionally, the SP483 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.
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_485_101_062711
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 specications
below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may
affect reliability.
VCC.......................................................................+7V
Input Voltages
Logic.........................-0.3V to (Vcc + 0.5V)
Drivers......................-0.3V to (Vcc + 0.5V)
Receivers.........................................+/-15V
ELECTRICAL CHARACTERISTICS
TMIN to TMAX and VCC = 5V +/-5% unless otherwise noted.
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP483/SP485 DRIVER
DC Characteristics
Differential Output Voltage Vcc Volts Unloaded; R = ∞ ; see gure 1
Differential Output Voltage 2 Vcc Volts With Load; R = 50Ω (RS-422);
see figure 1
Differential Output Voltage 1.5 Vcc Volts With Load; R = 27Ω (RS-485);
see figure 1
Change in Magnitude of Driver
Differential Output Voltage for
Complimentary states
0.2 Volts R = 27Ω or R = 50Ω; see figure 1
Driver Common Mode Output
Voltage
3 Volts R = 27Ω or R = 50Ω; 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 µA Applies to DE, DI, RE
Driver Short Circuit Current,
VOUT = HIGH
250 mA -7V ≤ VO ≤ +12V
Driver Short Circuit Current,
VOUT = LOW
250 mA -7V ≤ VO ≤ +12V
SP485 DRIVER
AC Characteristics
Maximum Data Rate 5 Mbps RE = 5V, DE = 5V
Driver Input to Output, tPLH 30 60 ns Figures 3 and 5, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Input to Output, tPHL 30 60 ns Figures 3 and 5, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Skew 5 10 ns Figures 3 and 5,
tSKEW = |tDPHL - tDPLH|
Driver Rise or Fall Time 15 40 ns From 10%-90%; RDIFF = 54Ω
CL1 = CL2 = 100pF; see gures 3
and 5
Output Voltages
Logic.........................-0.3V to (Vcc + 0.5V)
Drivers.............................................+/-15V
Receivers..................-0.3V to (Vcc + 0.5V)
Storage Temperature.......................-65˚C to +150˚C
Power Dissipation
8-pin NSOIC...................................................500mW
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_SP485_101_062711
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP485 DRIVER (continued)
AC Characteristics
Driver Enable to Output High 40 70 ns CL = 100pF, see gures 4 and 6,
S2 closed
Driver Enable to Output Low 40 70 ns CL = 100pF, see gures 4 and 6,
S1 closed
Driver Disable Time from High 40 70 ns CL = 15pF, see gures 2 and 8,
S2 closed
Driver Disable Time from Low 40 70 ns CL = 15pF, see gures 2 and 8,
S1 closed
SP483/SP485 RECEIVER
DC Characteristics
Differential Input Threshold -0.2 +0.2 Volts -7V ≤ VCM ≤ +12V
Input Hysteresis 10 mV VCM = 0V
Output Voltage High 2.4 5 Volts IO = -4mA, VID = +200mV
Output Voltage Low 0.0 0.4 Volts IO = +4mA, VID = -200mV
Three-State ( High Impedance)
Output Current
+/-1 µA 0.4V ≤ VO ≤ 2.4V; RE = 5V
Input Resistance 12 15 kΩ -7V ≤ VCM ≤ +12V
Input Current (A, B); VIN = 12V +1.0 mA DE = 0V, VCC = 0V or 5.25V,
VIN = 12V
Input Current (A, B); VIN = -7V -0.8 mA DE = 0V, VCC = 0V or 5.25V,
VIN = -7V
Short-Circuit Current 95 mA 0V ≤ VCM ≤ VCC
SP485 RECEIVER
AC Characteristics
Maximum Data Rate 5 Mbps RE = 0V, DE = 0V
Receiver Input to Output 20 45 200 ns tPLH ; Figures 3 and 7,
RDIFF = 54Ω, CL1 = CL2 = 100pF
Receiver Input to Output 20 45 200 ns tPHL ; Figures 3 and 7,
RDIFF = 54Ω, CL1 = CL2 = 100pF
Differential Receiver Skew
|tPHL - tPLH|
13 ns RDIFF = 54Ω, CL1 = CL2 = 100pF,
Figures 3 and 7
Receiver Enable to Output Low 45 70 ns CRL = 15pF, Figures 2 and 8;
S1 Closed
Receiver Enable to Output High 45 70 ns CRL = 15pF, Figures 2 and 8;
S2 Closed
Receiver Disable from LOW 45 70 ns CRL = 15pF, Figures 2 and 8;
S1 Closed
Receiver Disable from High 45 70 ns CRL = 15pF, Figures 2 and 8;
S2 Closed
ELECTRICAL CHARACTERISTICS
TMIN to TMAX and VCC = 5V +/-5% unless otherwise noted.
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_485_101_062711
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
POWER REQUIREMENTS
Supply Voltage VCC +4.75 +5.25 Volts
Supply Current
SP485 900 µA No Load; RE, DI = 0V or VCC;
DE = VCC
900 µA No Load; RE = 0V, DI = 0V or 5V;
DE = 0V
SP483 600 µA No Load; RE, DI = 0V or VCC;
DE = VCC
600 µA No Load; RE = 0V, DI = 0V or 5V;
DE = 0V
SP483 10 µA Shutdown Mode; DE = 0V, RE = VCC
ENVIRONMENTAL AND MECHANICAL
Operating Temperature
Commercial (_C_) 0 70 ºC
Industrial (_E_) -40 +85 ºC
Storage Temperature -65 +150 ºC
Package: Plastic DIP (_P), NSOIC (_N)
ELECTRICAL CHARACTERISTICS
TMIN to TMAX and VCC = 5V +/-5% unless otherwise noted.
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_SP485_101_062711
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP483 DRIVER
AC Characteristics
Maximum Date Rate 250 kbps
Driver Input to Output, tPLH 250 800 2000 ns tPLH; RDIFF = 54Ω, CL1 = CL2 = 100pF,
see gures 3 and 5
Driver Input to Output, tPHL 250 800 2000 ns tPHL; RDIFF = 54Ω, CL1 = CL2 = 100pF,
see gures 3 and 5
Driver Skew 100 800 ns see gures 3 and 5,
tSKEW = |tDPHL - tDPLH|
Driver Rise or Fall Time 250 2000 ns From 10%-90%; RDIFF = 54Ω
CL1 = CL2 = 100pF; see Figures 3
and 5
Driver Enable to Output High 250 2000 ns CL = 100pF, see gures 4 and 6,
S2 closed
Driver Enable to Output Low 250 2000 ns CL = 100pF, see gures 4 and 6,
S1 closed
Driver Disable Time from High 300 3000 ns CL = 15pF, see gures 4 and 6,
S2 closed
Driver Disable Time from Low 300 3000 ns CL = 15pF, see gures 4 and 6,
S1 closed
SP483 RECEIVER
AC Characteristics
Maximum Data Rate 250 kbps
Receiver Input to Output 250 2000 ns tPLH, tPHL; Figures 3 and 7:
RDIFF = 54Ω, CL1 = CL2 = 100pF
Differential Receiver Skew
|tPHL - tPLH|
100 ns RDIFF = 54Ω, CL1 = CL2 = 100pF,
see Figures 3 and 7
Receiver Enable to Output Low 20 50 ns CRL = 15pF, Figures 2 and 8;
S1 Closed
Receiver Enable to Output High 20 50 ns CRL = 15pF, Figures 2 and 8;
S2 Closed
Receiver Disable from LOW 20 50 ns CRL = 15pF, Figures 2 and 8;
S1 Closed
Receiver Disable from High 20 50 ns CRL = 15pF, Figures 2 and 8;
S2 Closed
SP483
Shutdown Timing
Time to Shutdown 50 200 600 ns RE = 5V, DE = 0V
Driver Enable from Shutdown
to Output High
2000 ns CL = 100pF; See Figures 4 and 6;
S2 Closed
Driver Enable from Shutdown
to Output Low
2000 ns CL = 100pF; See Figures 4 and 6;
S1 Closed
Receiver Enable from
Shutdown to Output High
2500 ns CL = 15pF; See Figures 4 and 6;
S2 Closed
Receiver Enable from
Shutdown to Output Low
2500 ns CL = 15pF; See Figures 4 and 6;
S1 Closed
TMIN to TMAX and VCC = 5V +/-5% unless otherwise noted.
ELECTRICAL CHARACTERISTICS
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_485_101_062711
PIN FUNCTION
TEST CIRCUITS
A
B
R
R
V
OD
V
OC
Figure 1. Driver DC Test Load Circuit
CL1
15pF
RO
A
B
A
B
DI
CL2
RL
Figure 3. RS-485 Driver/Receiver Timing Test
500Ω
CL
Output
Under
Test
S1
S2
VCC
Figure 4. Driver Timing Test Load #2 Circuit
Figure 2. Receiver Timing Test Load Circuit
1kΩ
1kΩCRL
Receiver
Output S1
S2
Test Point
VCC
Pin 1 - RO - Receiver Output
Pin 2 - RE - Receiver Output Enable Active LOW
Pin 3 - DE - Driver Output Enable Active HIGH
Pin 4 - DI - Driver Input
Pin 5 - GND - Ground Connection
Pin 6 - A - Driver Output / Receiver input
Non-Inverting
Pin 7 - B - Driver Output / Receiver Input Inverting
Pin 8 - Vcc - Positive Supply 4.75V ≤ Vcc ≤ 5.25V
Figure 5. Driver Propagation Delays
+3V
0V
DRIVER INPUT
A
B
DRIVER
OUTPUT
V
O
+
DIFFERENTIAL
OUTPUT
V
A
– V
B
0V
V
O
–
1.5V 1.5V
t
PLH
t
F
t
R
f
SP485
= 1MHz; t
R
≤ 10ns;
t
F
≤ 10ns
V
O
1/2V
O
1/2V
O
t
PHL
t
SKEW
= |t
DPLH
- t
DPHL
|
t
DPLH
t
DPHL
f
SP483
=
100kHz;
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_SP485_101_062711
Figure 6. Driver Enable and Disable Times
Figure 8. Receiver Enable and Disable Times
+3V
0V
DE
5V
VOL
A
, B
0V
1.5V 1.5V
tZL
tZH
VOH
A
, B 2.3V
2.3V
tLZ
tHZ
0.5V
0.5V
Output normally LOW
Output normally HIGH
fSP485 = 1MHz; tR≤ 10ns;
tF ≤ 10ns
fSP483 =
100kHz;
SWITCHING WAVEFORMS
FUNCTION TRUTH TABLES
INPUTS OUTPUTS
RE DE DI
LINE
CONDITION A B
X 1 1 No Fault 1 0
X 1 0 No Fault 0 1
X 0 X X Z Z
X 1 X Fault Z Z
Table 1. Transmit Function Truth Table
INPUTS OUTPUTS
RE DE A - B R
0 0 +0.2V 1
0 0 -0.2V 0
0 0 Inputs Open 1
1 0 X Z
Table 2. Receive Function Truth Table
V
OH
V
OL
R1.5V 1.5V
t
PHL
OUTPUT
V
OD2
+
V
OD2
–
A – B 0V 0V
t
PLH
INPUT
f
SP485
= 1MHz; t
R
≤ 10ns;
t
F
≤ 10ns
f
SP483
=
100kHz;
t
SKEW
= |t
PLH
- t
PHL
|
+3V
0V
5V
0V
1.5V 1.5V
t
ZL
t
ZH
R1.5V
1.5V
t
LZ
t
HZ
0.5V
0.5V
Output normally LOW
Output normally HIGH
V
IL
V
IH
R
RE
f
SP485
= 1MHz; t
R
≤ 10ns;
t
F
≤ 10ns
f
SP483
=
100kHz;
Figure 7. Receiver Propagation Delays
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_485_101_062711
The SP483 and SP485 are half-duplex dif-
ferential transceivers that meet the require-
ments of RS-485 and RS-422. Fabricated
with an Exar proprietary BiCMOS process,
this product requires 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 receiv-
ers 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 differ-
ences. Because RS-485 is a differential
interface, data is virtually immune to noise
in the transmission line.
Drivers
SP483 and SP485
The driver outputs of the 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 SP483 and SP485 have
an enable control line which is active HIGH.
A logic HIGH on DE (pin 3) will enable the
differential driver outputs. A logic LOW on the
DE(pin 3) will tri-state the driver outputs.
The transmitters of the 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
SP483 and SP485
The SP483 and SP485 receivers have dif-
ferential inputs with an input sensitivity as
low as ±200mV. Input impedance of the
receivers 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
SP483 and SP485 have a tri-state enable
control pin. A logic LOW on RE (pin 2) will
enable the receiver, a logic HIGH on RE (pin
2) will disable the receiver.
The receiver for the SP485 will operate up
to at least 10Mbps. 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 and oating.
Shutdown Mode
SP483
The SP483 is equipped with a Shutdown
mode. To enable the shutdown state, both
driver and receiver must be disabled simul-
taneously. A logic LOW on DE (pin 3) and a
Logic HIGH on RE (pin 2) will put the SP483
into Shutdown mode. In Shutdown, supply
current will drop to typically 1µA.
DESCRIPTION
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_SP485_101_062711
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_485_101_062711
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP483_SP485_101_062711
ORDERING INFORMATION
Model Temperature Range Package Types
SP483CN-L ......................................................................... 0°C to +70°C ................................................................................................8-pin NSOIC
SP483CN-L/TR ................................................................... 0°C to +70°C ................................................................................................8-pin NSOIC
SP483EN-L........................................................................ -40°C to +85°C...............................................................................................8-pin NSOIC
SP483EN-L/TR.................................................................. -40°C to +85°C...............................................................................................8-pin NSOIC
SP485CN-L ......................................................................... 0°C to +70°C ................................................................................................8-pin NSOIC
SP485CN-L/TR ................................................................... 0°C to +70°C ................................................................................................8-pin NSOIC
SP485CS-L......................................................................... 0°C to +70°C.................................................................................................8-pin PDIP
SP485EN-L........................................................................ -40°C to +85°C...............................................................................................8-pin NSOIC
SP485EN-L/TR.................................................................. -40°C to +85°C...............................................................................................8-pin NSOIC
SP485ES-L........................................................................ -40°C to +85°C...............................................................................................8-pin PDIP
REVISION HISTORY
DATE REVISION DESCRIPTION
07/28/04 -- Legacy Sipex Datasheet
07/14/10 1.0.0 Convert to Exar Format. Update ordering information as a result of discontinued
Lead type package options per PDN 081126-01. Remove all options and reference
to SP481; Part is EOL. Remove "GND" entry from Minimum column of SP483/485
driver DC Characteristic paramter "Differential output voltage - Unloaded".
June 2011 1.0.1 Remove Driver Short Circuit Current minimum. Change Vcc ABS MAX Rating from
+12V to +7V. Add 12k ohm minimum value to receiver Input Resistance. Change
SP485 receiver propagation delay MIN and TYP to 20 and 45ns respectively,
receiver Enable and Disable TYP and MAX to 45 and 70ns respectively. Remove
SP483CS-L and SP483ES-L ordering part number per PDN 110510-01.
Notice
EXAR Corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reliabil-
ity. EXAR Corporation assumes no representation that the circuits are free of patent infringement. Charts and schedules contained herein are only for
illustration purposes and may vary depending upon a user's specic application. While the information in this publication has been carefully checked;
no responsibility, however, is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can
reasonably be expected to cause failure of the life support system or to signicantly affect its safety or effectiveness. Products are not authorized for
use in such applications unless EXAR Corporation receives, in writting, assurances to its satisfaction that: (a) the risk of injury or damage has been
minimized ; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances.
Copyright 2011 EXAR Corporation
Datasheet June 2011
Send your serial transceiver technical inquiry with technical details to: serialtechsupport@exar.com
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
Note: /TR = Tape and Reel