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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
DESCRIPTION
• +5V Only
• Low Power BiCMOS
• Driver / Receiver Enable for Multi-Drop
congurations
• Low Power Shutdown mode (SP481E)
• Enhanced ESD Specications:
+/-15kV Human Body Model
+/-15kV IEC61000-4-2 Air Discharge
• Available in RoHS Compliant, Lead Free
Packaging.
SP481E / SP485E
Enhanced Low Power Half-Duplex
RS-485 Transceivers
The SP481E and SP485E are a family of half-duplex transceivers that meet the specications
of RS-485 and RS-422 serial protocols with enhanced ESD performance. The ESD toler-
ance has been improved on these devices to over +15kV for both Human Body Model and
IEC61000-4-2 Air Discharge Method. These devices are pin-to-pin compatible with Exar's
SP481 and SP485 devices as well as popular industry standards. As with the original ver-
sions, the SP481E and SP485E feature Exar's BiCMOS design allowing low power opera-
tion without sacricing performance. The SP481E and SP485E meet the requirements of
the RS-485 and RS-422 protocols up to 10Mbps under load. The SP481E is equipped with
a low power shutdown mode.
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
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 = +5.0V +/-5% unless otherwise noted.
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP481E/SP485E DRIVER
DC Characteristics
Differential Output Voltage GND Vcc Volts Unloaded; R = ∞ ; see Figure 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
3Volts 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
VOUT = LOW +/-250 mA -7V ≤ VO ≤ +12V
SP481E/SP485E DRIVER
AC Characteristics
Max. Transmission Rate 10 Mbps RE = 5V, DE = 5V; RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Input to Output, tPLH 30 60 ns See Figures 3 & 5, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Input to Output, tPLH
(SP485EMN ONLY)
30 80 ns
Driver Input to Output, tPHL 30 60 ns See Figures 3 & 5, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Input to Output, tPHL
(SP485EMN ONLY)
30 80 ns
Driver Skew 5 10 ns see Figures 3 and 5,
tSKEW = |tDPHL - tDPLH|
Driver Rise or Fall Time 15 40 ns From 10%-90%; RDIFF = 54Ω
CL1 = CL2 = 100pF; see Figures 3
and 6
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...................................................550mW
(derate 6.60mW/ºC above +70ºC)
8-pin PDIP....................................................1000mW
(derate 11.8mW/ºC above +70ºC)
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP481E/SP485E DRIVER (continued)
AC Characteristics
Driver Enable to Output High 40 70 ns CL = 100pF, see Figures 4 and 6,
S2 closed
Driver Enable to Output Low 40 70 ns CL = 100pF, see Figures 4 and 6,
S1 closed
Driver Disable Time from High 40 70 ns CL = 100pF, see Figures 4 and 6,
S2 closed
Driver Disable Time from Low 40 70 ns CL = 100pF, see Figures 4 and 6,
S1 closed
SP481E/SP485E RECEIVER
DC Characteristics
Differential Input Threshold -0.2 +0.2 Volts -7V ≤ VCM ≤ +12V
Differential Input Threshold
(SP485EMN ONLY)
-0.4 +0.4 Volts -7V ≤ VCM ≤ +12V
Input Hysteresis 20 mV VCM = 0V
Output Voltage High 3.5 Volts IO = -4mA, VID = +200mV
Output Voltage Low 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 7 95 mA 0V ≤ VO ≤ VCC
SP481E/SP485E RECEIVER
AC Characteristics
Max. Transmission Rate 10 Mbps RE = 0V, DE = 0V
Receiver Input to Output 20 45 100 ns tPLH ; See Figures 3 & 7, RDIFF =
54Ω, CL1 = CL2 = 100pF
Receiver Input to Output 20 45 100 ns tPHL ; See Figures 3 & 7, RDIFF =
54Ω, CL1 = CL2 = 100pF
Differential Receiver Skew
|tPHL - tPLH|
13 ns RDIFF = 54Ω, CL1 = CL2 = 100pF, see
Figures 3 and 7
Receiver Enable to Output Low 45 70 ns CRL = 15pF, Figures 2 & 8; S1
Closed
Receiver Enable to Output High 45 70 ns CRL = 15pF, Figures 2 & 8; S2
Closed
Receiver Disable from LOW 45 70 ns CRL = 15pF, Figures 2 & 8; S1
Closed
Receiver Disable from High 45 70 ns CRL = 15pF, Figures 2 & 8; S2
Closed
ELECTRICAL CHARACTERISTICS
TMIN to TMAX and VCC = +5.0V +/-5% unless otherwise noted.
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
PARAMETERS MIN. TYP. MAX. UNITS CONDITIONS
SP481E
Shutdown Timing
Time to Shutdown 50 200 600 ns RE = 5V, DE = 0V
Driver Enable from Shutdown
to Output High
40 100 ns CL = 100pF; See Figures 4 and 6;
S2 Closed
Driver Enable from Shutdown
to Output Low
40 100 ns CL = 100pF; See Figures 4 and 6;
S1 Closed
Receiver Enable from
Shutdown to Output High
300 1000 ns CL = 15pF; See Figures 2 and 8; S2
Closed
Receiver Enable from
Shutdown to Output Low
300 1000 ns CL = 15pF; See Figures 2 and 8; S1
Closed
POWER REQUIREMENTS
Supply Voltage VCC +4.75 +5.25 Volts
Supply Current
SP481E/SP485E
No Load 900 µA RE, DI = 0V or VCC; DE = VCC
600 µA RE = 0V, DI = 0V or 5V; DE = 0V
SP481E
Shutdown Mode 10 µA DE = 0V, RE = VCC
ENVIRONMENTAL AND MECHANICAL
Operating Temperature
Commercial (_C_) 0 70 ºC
Industrial (_E_) -40 +85 ºC
(_M_) -40 +125 ºC
Storage Temperature -65 +150 ºC
Package
Plastic DIP (_P)
NSOIC (_N)
ELECTRICAL CHARACTERISTICS
TMIN to TMAX and VCC = +5.0V +/-5% unless otherwise noted.
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
PIN FUNCTION
TEST CIRCUITS
A
B
R
R
V
OD
V
OC
Figure 1. RS-485 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
VO+
DIFFERENTIAL
OUTPUT
VA – VB
0V
VO–
1.5V 1.5V
tPLH
tF
tR
tR
≤ 10ns;
tF ≤ 10ns
VO1/2V
O1/2V
O
tPHL
tSKEW
= |tDPLH
- tDPHL|
tDPLH tDPHL
f ≥
1MHz;
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
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
f = 1MHz; tR
< 10ns; tF < 10ns
VOH
A
, B 2.3V
2.3V
tLZ
tHZ
0.5V
0.5V
Output normally LOW
Output normally HIGH
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
VOH
VOL
R1.5V 1.5V
tPHL
f = 1MHz; tR 10ns; tF
≤ 10ns
OUTPUT
VOD2+
VOD2–
A
– B 0V 0V
tPLH
INPUT
≤
+3V
0V
5V
0V
1.5V 1.5V
t
ZL
t
ZH
f = 1MHz; t
R
≤ 10ns; t
F
≤ 10ns
R1.5V
1.5V
t
LZ
t
HZ
0.5V
0.5V
Output normally LOW
Output normally HIGH
V
IL
V
IH
R
RE
Figure 7. Receiver Propagation Delays
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
The SP481E and SP485E are half-duplex
differential 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
The driver outputs of the SP481E and
SP485E 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 volt-
age levels. The drivers of the SP481E and
SP485E 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 SP481E and SP485E
will operate up to at least 10Mbps.
Receivers
The SP481E and SP485E receivers have
differential 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
SP481E and SP485E have a tri-state en-
able 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 SP481E and SP485E
will operate up to at least 10Mbps. The
receiver for each of the two 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
SP481E
The SP481E 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 SP481E
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 SP481E,485E_104_052413
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
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Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP481E,485E_104_052413
ORDERING INFORMATION
Model Temperature Range Package Types
SP481ECN-L ....................................................................... 0°C to +70°C ................................................................................................8-pin NSOIC
SP481ECN-L/TR ................................................................. 0°C to +70°C ................................................................................................8-pin NSOIC
SP481EEN-L/.................................................................... -40°C to +85°C...............................................................................................8-pin NSOIC
SP481EEN-L/TR................................................................. -40°C to +85°C.............................................................................................8-pin NSOIC
SP485ECN-L ....................................................................... 0°C to +70°C ................................................................................................8-pin NSOIC
SP485ECN-L/TR ................................................................. 0°C to +70°C ................................................................................................8-pin NSOIC
SP485ECP-L....................................................................... 0°C to +70°C.................................................................................................8-pin PDIP
SP485EEN-L..................................................................... -40°C to +85°C................................................................................................8-pin NSOIC
SP485EEN-L/TR................................................................ -40°C to +85°C...............................................................................................8-pin NSOIC
SP485EEP-L...................................................................... -40°C to +85°C...............................................................................................8-pin PDIP
SP485EMN-L..................................................................... -40°C to +125°C.............................................................................................8-pin NSOIC
SP485EMN-L/TR............................................................... -40°C to +125°C.............................................................................................8-pin NSOIC
REVISION HISTORY
DATE REVISION DESCRIPTION
May 11/07 -- Legacy Sipex Datasheet
12/18/08 1.0.0 Convert to Exar Format. Update ordering information as a result of discontinued
Lead type package options per PDN 081126-01. Remove "Top Mark" information
from ordering page.
11/19/09 1.0.1 Correct table 1 error for driver output A and B outputs
08/08/10 1.0.2 Change SP485EMN-L and SP485EMN-L/TR temperature range error from +85C to
+125C in ordering information section.
05/27/11 1.0.3 Remove driver minimum limits of propagation delay and Rise/Fall time. Remove
SP481ECP-L and SP481EEP-L per PDN 110510-01
05/24/13 1.0.4 Correct type errors per PCN 13-0503-01
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 2013 EXAR Corporation
Datasheet May 2013
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