EXAR SP1481ECN-L/TR

SP1481E/SP1485E
Enhanced Low Power Half-Duplex
RS-485 Transceivers
■ +5V Only
■ Low Power BiCMOS
■ Driver/Receiver Enable for Multi-Drop
configurations
■ Low Power Shutdown Mode
(SP1481E)
■ Enhanced ESD Specifications:
+15KV Human Body Model
+15KV IEC1000-4-2 Air Discharge
+8KV IEC1000-4-2 Contact Discharge
RO 1
R
8 VCC
RE 2
7 B
DE 3
6 A
DI 4
D
5 GND
Now Available in Lead Free Packaging
description
The SP1481E and the SP1485E are a family of half-duplex transceivers that meet the
specifications of RS-485 and RS-422 serial protocols with enhanced ESD performance. The
ESD tolerance has been improved on these devices to over +15KV for both Human Body
Model and IEC1000-4-2 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 versions, the SP1481E and the SP1485E feature Exar's BiCMOS design allowing
low power operation without sacrificing performance. The SP1481E and SP1485E meet the
requirements of the RS-485 and RS-422 protocols up to 20Mbps under load. The SP1481E
is equipped with a low power Shutdown mode.
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
ABSOLUTE MAXIMUM RATINGS
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
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.
VCC..............................................................................+7V
Power Dissipation per Package
8-pin NSOIC (derate 6.60mW/oC above +70oC).........................550mW
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
SP1481E/SP1485E 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
VOUT = HIGH
VOUT = LOW
MIN.TYP.
MAX.
UNITSCONDITIONS
3.5
2
1.5
VCC
VCC
VCC
Volts
Volts
Volts
Unloaded; R = ∞; see Figure 1
with load; R = 50Ω; (RS-422);
see Figure 1
with load; R = 27Ω; (RS-485);see Figure 1
0.2
Volts
R = 27Ω or R = 50Ω; see Figure 1
2.0
3
0.8
±10
±250
Volts
Volts
Volts
μA
mA
R = 27Ω or R = 50Ω; see Figure 1
Applies to DE, DI, RE
Applies to DE, DI, RE
Applies to DE, DI, RE
±250
mA
‑7V ≤ VO ≤ +12V
‑7V ≤ VO ≤ +12V
SP1481E/SP1485E driver
AC Characteristics
Maximum Data Rate
20
Mbps
Driver Input to Output
20
30
ns
Driver Input to Output 20
40
ns
(SP1485EMN ONLY)
RE = 5V, DE = 5V; RDIFF = 54Ω,
CL1 = CL2 = 100pF
tPLH; RDIFF = 54Ω, CL1 = CL2 = 100pF;
see Figures 3 and 5
tPLH; RDIFF = 54Ω, CLI = CL2 = 100pF;
See Figures 3 and 5
Driver Input to Output
20
30
ns
Driver Input to Output
20
40
ns
(SP1485EMN ONLY)
Driver Skew
3
5
ns
Driver Rise or Fall Time
8
20
ns
Driver Enable to Output High
40
70
ns
Driver Enable to Output Low
40
70
ns
Driver Disable Time from Low
40
70
ns
Driver Disable Time from High
40
70
ns
tPHL; RDIFF = 54Ω, CL1 = CL2 = 100pF;
see Figures 3 and 5
tPHL; RDIFF = 54Ω, CL1 = CL2 = 100pF;
see Figures 3 and 5
see Figures 3 and 5, tSKEW = | tPLH - tPHL |
From 10% to 90%; RDIFF = 54Ω,
CL1 = CL2 = 100pF; see Figures 3 & 6
CL = 100pF; see Figures 4 & 6; S2 closed
CL = 100pF; see Figures 4 & 6; S1 closed
CL = 100pF; see Figures 4 & 6; S1 closed
CL = 100pF; see Figures 4 & 6; S2 closed
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
SPECIFICATIONS (continued)
TMIN to TMAX and VCC = 5V ± 5% unless otherwise noted
PARAMETERS
MIN.TYP.
MAX.
UNITSCONDITIONS
Differential Input Threshold
-0.2
+0.2
Volts
‑7V ≤ VCM ≤ +12V
Differential Input Threshold
-0.4
+0.4
Volts
‑7V ≤ VCM ≤ +12V
SP1481E/SP1485E RECEIVER
DC Characteristics
(SP1485EMN ONLY)
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
0.4V ≤ VO ≤ 2.4V; RE = 5V
Three-State (High Impedance)
Output Current
±1
µA
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
95
mA
0V ≤ VO ≤ VCC
Mbps
RE = 0V, DE = 0V
Input Resistance
Short-Circuit Current 7
SP1481E/SP1485E RECEIVER
AC Characteristics
Maximum Data Rate
Receiver Input to Output
20
25
70
ns
Receiver Input to Output
25
70
ns
Diff. Receiver Skew ItPLH-tPHLI
5
10
45
Output High
Receiver Disable from Low
tPLH; RDIFF = 54Ω,
CL1 = CL2 = 100pF; Figures 3 & 7
tPHL; RDIFF = 54Ω,
CL1 = CL2 = 100pF; Figures 3 & 7
ns
RDIFF = 54Ω; CL1 = CL2 = 100pF;
Figures 3 & 7
70
ns
CRL = 15pF; Figures 2 & 8; S1 closed
45
70
ns
CRL = 15pF; Figures 2 & 8; S2 closed
45
70
ns
CRL = 15pF; Figures 2 & 8; S1 closed
Receiver Disable from High 45
70
ns
CRL = 15pF; Figures 2 & 8; S2 closed
Receiver Enable to
Output Low
Receiver Enable to
SP1481E
Shutdown Timing
Time to Shutdown
50
200
600
ns
RE = 5V, DE = 0V
40
100
ns
CL = 100pF; See Figures 4 & 6; S2 closed
40
100
ns
CL = 100pF; See Figures 4 & 6; S1 closed
300
1000
ns
CL = 15pF; See Figures 2 & 8; S2 closed
300
1000
ns
CL = 15pF; See Figures 2 & 8; S1 closed
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
+4.75
+5.25
Supply Current
Volts
No Load
900
μA
RE, DI = 0V or VCC; DE = VCC
600
μA
RE = 0V, DI = 0V or 5V; DE = 0V
SP1481E/1485E
SP1481E
Shutdown Mode
10
μA
DE = 0V, RE=VCC
environmental and mechanical
Operating Temperature
Commercial (_C_)
0
+70
°C
Industrial (_E_)
-40
+85
°C
(_M_)
-40
+125
°C
Storage Temperature
-65
+150
°C
Package
NSOIC (_N)
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
Pin function
R
RO 1
8
VCC
RE 2
7
B
DE 3
6
A
5
GND
Pin 1 – RO – Receiver Output. Pin 2 – RE – Receiver Output Enable Active LOW.
Pin 4 – DI – Driver Input.
Pin 5 – GND – Ground Connection.
D
DI 4
Pin 3 – DE – Driver Output Enable Active HIGH.
SP485
Pin 6 – A – Driver Output/Receiver Input Non-inverting.
Top View
Pin 7 – B – Driver Output/Receiver Input Inverting.
SP1481E and SP1485E
Pinout (Top View)
Pin 8 – Vcc – Positive Supply 4.75V<Vcc< 5.25V.
A
VOD
1K
Test Point
Receiver
Output
R
VCC
S1
CRL
1K
VOC
R
S2
B
Figure 1. RS-485 Driver DC Test Load Circuit
Figure 2. Receiver Timing Test Load Circuit
3V
DE
DI
CL1
A
B
A
RDIFF
B
CL2
Output
Under
Test CL
RO
15pF
500
S1
VCC
S2
Figure 3. RS-485 Driver/Receiver Timing Test Circuit
DI
DRIVER
OUTPUT
f = 1MHz; tR < 1ns; tF < 1ns
+3V
1.5V
0V
B
A
Figure 4. RS-485 Driver Timing Test Load #2 Circuit
1.5V
tPLH
tPHL
VO 1/2VO
tPLH
1/2VO
DIFFERENTIAL VO+
OUTPUT 0V
VA – VB VO–
tSKEW
tSKEW
tR
tF
Figure 5. Driver Propagation Delays
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
INPUTS OUTPUTS
RE DE LINE
DI CONDITION B
A
X
1
1
No Fault
0
1
X
1
0
No Fault
1
0
X
0
X
X
Z
Z
X
1
X
Fault
Z
Z
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
Table 1. Transmit Function Truth Table
f = 1MHz; f= tR < 1ns; tF < 1ns
DE
A, B
A, B
+3V
1.5V
0V
1.5V
tZL
5V
2.3V
VOL
VOH
2.3V
0V
tLZ
Output normally LOW
0.5V
Output normally HIGH
0.5V
tZH
tHZ
Figure 6. Driver Enable and Disable Times
A–B
R
V0D2+
0V
V0D2–
VOH
VOL
INPUT
1.5V
tPHL
OUTPUT
0V
1.5V
tPHL
f = 1MHz; tR < 1ns; tF < 1ns
Figure 7. Receiver Propagation Delays
RE
R
R
+3V
0V
5V
VIL
VIH
0V
f = 1MHz; tR < 1ns; tF < 1ns
1.5V
1.5V
tZL
1.5V
1.5V
tLZ
Output normally LOW
0.5V
Output normally HIGH
0.5V
tZH
tHZ
Figure 8. Receiver Enable and Disable Times
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
DESCRIPTION
A logic LOW on RE (pin 2) will enable the
receiver, a logic HIGH on RE (pin 2) will disable the receiver. The SP1481E and SP1485E are half-duplex
differential transceivers that meet the requirements of RS-485 and RS-422. Fabricated
with a Exar proprietary BiCMOS process,
these products require a fraction of the power
of older bipolar designs.
The receiver for the SP1481E and SP1485E
will operate up to at least 20Mbps. 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.
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.
Shutdown Mode
SP1481E
The SP1481E is 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 3) and a logic HIGH
on RE (pin 2) will put the SP1481E into Shutdown mode. In Shutdown, supply current will
drop to typically 1μA.
Drivers
ESD Tolerance
The driver outputs of the SP1481E and
SP1485E 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 SP1481E, and
SP1485E 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 DE (pin 3) will tri-state the
driver outputs.
The SP1481E Family incorporates ruggedized ESD cells on all driver output and
receiver input pins. The ESD structure is
improved over our previous family for more
rugged applications and environments
sensitive to electro-static discharges and
associated transients. The improved ESD
tolerance is at least ±15kV without damage
nor latch-up. There are different methods of ESD testing
applied:
a) MIL-STD-883, Method 3015.7
b) IEC1000-4-2 Air-Discharge
c) IEC1000-4-2 Direct Contact
The transmitters of the SP1481E and
SP1485E will operate up to at least
20Mbps.
The Human Body Model has been the
generally accepted ESD testing method
for semiconductors. This method is also
specified in MIL-STD-883, Method 3015.7
for ESD testing. The premise of this ESD
test is to simulate the human body’s potential
to store electro-static energy and discharge
it to an integrated circuit. The simulation is
performed by using a test model as shown
in Figure 7. This method will test the IC’s
capability to withstand an ESD transient during normal handling such as in manufacturing areas where the ICs tend to be handled
frequently. Receivers
The SP1481E and SP1485E 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
SP1481E and SP1485E have a tri-state
enable control pin. Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
There are two methods within IEC1000-4-2,
the Air Discharge method and the Contact
Discharge method.
The IEC-1000-4-2, formerly IEC801-2, is
generally used for testing ESD on equipment
and systems. For system manufacturers,
they must guarantee a certain amount of ESD
protection since the system itself is exposed
to the outside environment and human presence. The premise with IEC1000-4-2 is that
the system is required to withstand an amount
of static electricity when ESD is applied to
points and surfaces of the equipment that
are accessible to personnel during normal
usage. The transceiver IC receives most
of the ESD current when the ESD source
is applied to the connector pins. The test
circuit for IEC1000-4-2 is shown on Figure 8. R
RSS
R
RC
C
SW2
SW2
SW1
SW1
Device
Under
Test
C
CSS
DC Power
Source
Figure 7. ESD Test Circuit for Human Body Model
Contact-Discharge Module
R
RSS
R
RC
C
RV
SW2
SW2
SW1
SW1
DC Power
Source
Device
Under
Test
C
CSS
RS and RV add up to 330Ω for
for IEC1000-4-2.
Figure 8. ESD Test Circuit for IEC1000-4-2
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
With the Air Discharge Method, an ESD
voltage is applied to the equipment under
test (EUT) through air. This simulates an
electrically charged person ready to connect
a cable onto the rear of the system only to
find an unpleasant zap just before the person
touches the back panel. The high energy
potential on the person discharges through
an arcing path to the rear panel of the system
before he or she even touches the system. This energy, whether discharged directly or
through air, is predominantly a function of the
discharge current rather than the discharge
voltage. Variables with an air discharge such
as approach speed of the object carrying the
ESD potential to the system and humidity
will tend to change the discharge current. For example, the rise time of the discharge
current varies with the approach speed.
30A
15A
0A
t=0ns
Figure 9. ESD Test Waveform for IEC1000-4-2
switch (SW1) is on. Now that the capacitor
is charged, the second switch (SW2) is on
while SW1 switches off. The voltage stored
in the capacitor is then applied through RS,
the current limiting resistor, onto the device
under test (DUT). In ESD tests, the SW2
switch is pulsed so that the device under
test receives a duration of voltage.
The Contact Discharge Method applies the
ESD current directly to the EUT. This method
was devised to reduce the unpredictability
of the ESD arc. The discharge current rise
time is constant since the energy is directly
transferred without the air-gap arc. In situations such as hand held systems, the ESD
charge can be directly discharged to the
equipment from a person already holding
the equipment. The current is transferred
on to the keypad or the serial port of the
equipment directly and then travels through
the PCB and finally to the IC.
For the Human Body Model, the current
limiting resistor (RS) and the source capacitor
(CS) are 1.5kΩ an 100pF, respectively. For
IEC-1000-4-2, the current limiting resistor
(RS) and the source capacitor (CS) are 330Ω
an 150pF, respectively. The circuit model in Figures 7 and 8 represent
the typical ESD testing circuit used for all
three methods. The CS is initially charged
with the DC power supply when the first
Sp1481E,
SP1485E
Family
The higher CS value and lower RS value in
the IEC1000-4-2 model are more stringent
than the Human Body Model. The larger
storage capacitor injects a higher voltage
to the test point when SW2 is switched on. The lower current limiting resistor increases
the current charge onto the test point. Human Body
MODEL
Air Discharge
Driver Outputs ±15kV
Receiver Inputs ±15kV
t=30ns
t
IEC1000-4-2
Direct Contact
±15kV ±8kV
±15kV ±8kV
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
Level
4
4
SP1481E-1485E_100_061609
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com
SP1481E-1485E_100_061609
ordering information
ModelTemperature RangePackage
SP1481ECN-L.................................................... 0˚C to +70˚C................................................ 8-pin Narrow SOIC
SP1481ECN-L/TR...............................................0˚C to +70˚C................................................ 8-pin Narrow SOIC
SP1481EEN-L.................................................. .-40˚C to +85˚C.............................................. 8-pin Narrow SOIC
SP1481EEN-L/TR............................................ .-40˚C to +85˚C.............................................. 8-pin Narrow SOIC
SP1485ECN-L.................................................... 0˚C to +70˚C................................................ 8-pin Narrow SOIC
SP1485ECN-L/TR.............................................. 0˚C to +70˚C................................................ 8-pin Narrow SOIC
SP1485EEN-L...................................................-40˚C to +85˚C.............................................. 8-pin Narrow SOIC
SP1485EEN-L/TR.............................................-40˚C to +85˚C.............................................. 8-pin Narrow SOIC
SP1485EMN-L.................................................-40˚C to +125˚C............................................. 8-pin Narrow SOIC
DATE
REVISION DESCRIPTION
03/08/07
J
06/16/09
1.0.0
Legacy Sipex Datasheet
Convert to Exar format, update ordering information and
change revision to 1.0.0
Notice
EXAR Corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reliability. 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 specific 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 significantly 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 2009 EXAR Corporation
Datasheet June 2009
Send your Interface technical inquiry with technical details to: [email protected]
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
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10
SP1481E-1485E_100_061609