SP3495E-3497E
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND
ADVANCED FAILSAFE
MAY 2009
GENERAL DESCRIPTION
The SP3495E - SP3497E transceivers are suitable
for high speed bidirectional communication on
multipoint bus transmission lines. They are designed
for balanced data transmission and comply with both
RS-485 and RS-422 EIA standards. Each device
contains one differential driver and one differential
receiver
Driver differential outputs and receiver differential
inputs are connected internally to form a half-duplex
input/output to the RS-485 bus. Separate RE and DE
pins enable and disable the driver and receiver
independently or may be externally connected
together as a direct control. The device enters a low
power shutdown mode if both driver and receiver are
disabled. the bus-pin outputs of disabled or powered
down devices are in high impedance state. The high
impedance driver output is maintained over the entire
common-mode voltage range of -7V to +12V.
SP3495E - SP3497E operates from a single 3.3V
power supply. SP3495E - SP3497E transceivers load
the data bus only half as much as a standard RS-485
unit load. This allows up to 64 devices to be
connected simultaneously on a bus without violating
required RS-485 signal margin and without using
repeaters. Excessive power dissipation caused by
bus contention or by shorting outputs to ground or a
voltage source is prevented by short circuit protection
and thermal shutdown. This feature forces the driver
output into high impedance state if the absolute value
of the output current exceeds 250mA or if junction
temperature exceeds 165°C. Receivers will fail-safe
to a logic high output state if the inputs are
unconnected (floating) or shorted. All RS-485 inputs
REV. 1.0.0
and outputs are ESD protected up to +/-15kV Human
Body Model.
FEATURES
• 3.3V Single Supply Operation
• High Speed up to 32Mbps
• Robust +/-15kV ESD protection
• Hot Swap glitch protection
• Advanced Fail-safe Receiver Inputs
• Half Unit Load, 64 Transceivers on bus
• Driver short circuit current limit and thermal
shutdown for overload protection
• Low Current 1uA shutdown mode
TYPICAL APPLICATIONS
• Factory Automation Controls
• Motor Control
• Industrial Process Control
• Building Automation
• Security Systems
• Remote Utility Meter Reading
• Long or un-terminated transmission lines
FIGURE 1. TYPICAL APPLICATION CIRCUIT
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com
SP3495E-3497E
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
REV. 1.0.0
FIGURE 2. PIN OUT ASSIGNMENT
SP3495E 8-Pin Half Duplex
RO
1
R
2
RE
DE 3
4
DI
8 VCC
7 B
6 A
D
5
GND
SP3496E 8-pin Full Duplex
Vcc
R
D
GND
1
2
R
8 A
7
B
6
3
D
4
Z
5 Y
SP3497E 14-pin Full Duplex
NC
R
1
2
R
RE 3
4
DE
14
13
12
11
10
D 5
6
GND
7
GND
D
9
8
Vcc
NC
A
B
Z
Y
NC
ORDERING INFORMATION
PART NUMBER
PACKAGE
OPERATING TEMPERATURE
RANGE
DEVICE STATUS
SP3495EEN-L
8-pin Narrow SOIC
-40°C to +85°C
Active
SP3495EEN-L/TR
8-pin Narrow SOIC
-40°C to +85°C
Active
SP3496EEN-L
8-pin Narrow SOIC
-40°C to +85°C
Active
SP3496EEN-L/TR
8-pin Narrow SOIC
-40°C to +85°C
Active
SP3497EEN-L
14-pin Narrow SOIC
-40°C to +85°C
Active
SP3497EEN-L/TR
14-pin Narrow SOIC
-40°C to +85°C
Active
Note: To order Tape and Reel option include "/TR" in ordering part number. All packages are Pb-free/ RoHS compliant.
2
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
PIN DESCRIPTIONS
Pin Assignments
PIN NUMBER
HALF DUPLEX
FULL DUPLEX
SP3495E
SP3496E
SP3497E
1
2
2
2
3
-
-
3
4
PIN NAME
TYPE
DESCRIPTION
RO
O
Receiver Output. When RE is low and if (AB) ≥ -40mV, RO is High. If (A-B) ≤ -200mV,
RO is Low.
I
Receiver Output Enable, When RE is Low,
RO is enabled. When RE is High, RO is
high impedance. RE should be High and
DE should be low to enter shutdown mode.
RE is a hot-swap input.
I
Driver Output Enable. When DE is High,
outputs are enabled. When DE is low, outputs are high impedance. DE should be low
and RE should be High to enter shutdown
mode. DE is a hot-swap input
Driver Input. With DE high, a low level on DI
forces Non-Inverting output low and inverting output high. Similarly, a high level on DI
forces Non-Inverting output High and Inverting output Low.
RE
DE
4
3
5
DI
I
5
4
6, 7
GND
Pwr
6
-
-
A
O
Non-Inverting Receiver Input and NonInverting Driver Output
7
-
-
B
O
Inverting Receiver Input and Inverting
Driver Output
8
1
14
Vcc
Pwr
+3.3V power supply input. Bypass with
0.1uF capacitor.
-
8
12
A
I
Non-Inverting Receiver Input
-
7
11
B
I
Inverting Reciever Input
-
5
9
Y
O
Non-Inverting Driver Output
-
6
10
Z
O
Inverting Driver Output
-
-
1, 8, 13
NC
-
No Connect, not internally connected
Pin type: I=Input, O=Output.
3
Ground
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
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 to the
specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability and cause permanent
damage to the device.
VCC
+6.0V
Input Voltage at control pins (RE, DE and DI)
-0.5V to (VCC + 0.3V)
Voltage Range on A and B pins
-9V to +14V
Storage Temperature Range
-65°C to + 150°C
Power Dissipation
Maximum Junction Temperature 150°C
8-Pin SO θJA = 128.4°C/W
14-Pin SO θJA = 86°C/W
CAUTION:
ESD (Electrostatic Discharge) sensitive device. Permanent damage may occur on unconnected devices subject to high energy electrostatic fields. Unused
devices must be stored in conductive foam or shunts. Personnel should be properly grounded prior to handling this device. The protective foam should be
discharged to the destination socket before devices are removed.
ELECTRICAL CHARACTERISTICS
UNLESS OTHERWISE NOTED: VCC = +3.0V TO +3.6V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT
VCC = +3.3V AND 25OC.
SYMBOL
PARAMETERS
MIN.
TYP.
MAX.
UNITS
Vcc
V
CONDITIONS
DRIVER DC CHARACTERISTICS
VOD
∆VOD
Differential Driver Output
Change in Magnitude of Differential
Output
No Load
2.0
RL = 100Ω (RS-422), Figure 3
1.5
RL = 54Ω (RS-485), Figure 3
1.5
VCM = -7V, Figure 4
1.5
VCM = +12V, Figure 4
-0.20
0.20
V
RL = 100Ω (RS-422), Figure 3,
See note 1
-0.20
0.20
RL = 54Ω (RS-485), Figure 3,
See note 1
-0.20
0.20
VCM = -7V, Figure 4, See
note 1
VCM = +12V, Figure 4, See note
1
-0.20
0.20
Driver Common Mode Output
Voltage steady state
1.3
2.5
V
Figure 3
∆VOC
Change in Magnitude of Common
Mode Output Voltage
-0.2
0.2
V
Figure 3, See note 1
IDSC
Driver Short Circuit Current Limit
-250
VOC
250
4
mA
VOUT Forced to -7V, Figure 5
mA
VOUT Forced to +12V, Figure 5
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
UNLESS OTHERWISE NOTED: VCC = +3.0V TO +3.6V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT
VCC = +3.3V AND 25OC.
SYMBOL
VIH
PARAMETERS
MIN.
TYP.
2.0
IIN
UNITS
CONDITIONS
V
Logic Input High
V
Logic Input Low
Logic Input Thresholds (DI, DE, RE)
VIL
VHYS
MAX.
0.8
Driver Input Hysteresis
100
Logic Input Current (DI, DE and RE)
10
-10
mV
TA = 25°C
uA
IN = 0V
uA
IN = Vcc
Driver AC Characteristics
freq
Data Signaling Rate
32
tPLH
Driver Propagation Delay (low to
High)
5
Driver Propagation Delay (High to
Low)
5
tPHL
tR
Driver Rise Time
Mbps 1/tUI, Duty Cycle 40 to 60%
11
24
ns
CL = 50pF, RL = 54Ω,
freq = 8MHz, Figures 6 and 7
11
24
ns
CL = 50pF, RL = 54Ω,
freq = 8MHz, Figures 6 and 7
2.5
4.5
10
ns
CL = 50pF, RL = 54Ω,
freq = 8MHz, Figures 6 and 7
tF
Driver Fall time
2.5
4.5
10
ns
CL = 50pF, RL = 54Ω,
freq = 8MHz, Figures 6 and 7
|tPLH-tPHL|
Differential Pulse Skew
3
ns
Figures 6 and 7
tOZH
Driver Enable to Output High
50
ns
CL = 50pF, RL = 500Ω, Figures
8 and 9
tOZL
Driver Enable to Outut Low
50
ns
CL = 50pF, RL = 500Ω, Figures
10 and 11
tOHZ
Driver Disable from Output High
50
ns
CL = 50pF, RL = 500Ω, Figures
8 and 9
tOLZ
Driver Disable from Output Low
50
ns
CL = 50pF, RL = 500Ω, Figures
10 and 11
tOZV
Shutdown to Driver Output Valid
6
us
CL = 50pF, RL = 500Ω
50
600
ns
Note 2 and 3
-290
500
uA
DE = 0, Vcc = 0 or 3.3V
VA or VB = 12V, other input 0V
tSHDN
Time to Shutdown
RECEIVER DC CHARACTERISTICS
IIN
Input Current (A, B pins)
VA or VB = -7V, other input 0V
VIH
VIL
Receiver Differential Thresholds
(VA - VB)
-200
Receiver Input Hysteresis
VOH
Receiver Output Voltage High
VOL
Receiver Output Voltage Low
mV
-7V ≤ VCM ≤ 12V, rising
-125
mV
-7V ≤ VCM ≤ 12V, falling
25
mV
VCM = 0V
-85
-40
2.4
0.4
5
V
IOUT = -8mA, VID = 200mV
V
IOUT = 8mA, VID = -200mV
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
UNLESS OTHERWISE NOTED: VCC = +3.0V TO +3.6V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT
VCC = +3.3V AND 25OC.
SYMBOL
IOZ
PARAMETERS
High-Z Receiver Output Current
MIN.
TYP.
MAX.
-1
1
IOSS
RIN
Receiver Output Short Circuit
Current
-95
Receiver Input Resistance
24
95
UNITS
CONDITIONS
uA
RE = Vcc, VOUT = 0V
uA
RE = Vcc, VOUT = Vcc
mA
VOUT = 0V
mA
VOUT = Vcc
KΩ
-7V ≤ VCM ≤ 12V
RECEIVER AC CHARACTERISTICS
freq
Data Signaling Rate
32
Mbps 1/tUI, Duty Cycle 40 to 60%
tPLH
Receiver Propagation Delay (Low to
High)
15
40
ns
VID = +/-2V, CL = 15pF, Freq =
8MHz, Figure 12 and 13
tPHL
Receiver Propagation Delay (High to
Low)
15
40
ns
VID = +/-2V, CL = 15pF, Freq =
8MHz, Figure 12 and 13
skew
Receiver Propagation Delay Skew
3
ns
VID = +/-2V, CL = 15pF, Freq =
8MHz, Figure 12 and 13
skew = |tPLH-tPHL|
tR
Receiver Output Rise Time
1
2
6
ns
CL = 15pF, Freq = 8MHz
tF
Receiver Output Fall Time
1
2
6
ns
CL = 15pF, Freq = 8MHz
tZH
Receiver Enable to Output High
50
ns
CL = 15pF, RL = 1kΩ,
Figure 14
tZL
Receiver Enable to Output Low
50
ns
CL = 15pF, RL = 1kΩ,
Figure 14
tHZ
Receiver Output High to Disable
50
ns
CL = 15pF, RL = 1kΩ,
Figure 14
tLZ
Receiver Output Low to Disable
50
ns
CL = 15pF, RL = 1kΩ,
Figure 14
tZH(SHDN)
Shutdown to Receiver Output Valid
High
6
us
CL = 15pF, RL = 1kΩ
tZL(SHDN)
Shutdown to Receiver Output Valid
Low
6
us
CL = 15pF, RL = 1kΩ
600
ns
Note 2 and 3
tSHDN
Time to Shutdown
50
POWER REQUIRMENTS AND RECOMMENDED OPERATING CONDITIONS
Vcc
Supply Voltage
ICC1
3.0
3.3
3.6
V
Supply Current - Driver Enabled
5.0
mA
DE = Vcc, No Load, RE and DI
= 0V or Vcc
ICC2
Supply Current - Receiver Enabled
5.0
mA
DE = 0V, RE = 0V, No Load
ICC3
Supply Current - Shutdown Mode
1
6
uA
DE = 0V, RE = Vcc, DI = Vcc or
0V
TSD
Thermal Shutdown Temperature
165
6
°C
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
UNLESS OTHERWISE NOTED: VCC = +3.0V TO +3.6V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT
VCC = +3.3V AND 25OC.
SYMBOL
PARAMETERS
MIN.
Thermal Shutdown Hysteresis
ESD Protection at Pins A, B, Y and Z
TYP.
MAX.
UNITS
20
°C
+/-15
kV
CONDITIONS
Human Body Model
NOTE:
1.
Change in Magnitude of Differential Output Voltage and Change in Magnitude of Common Mode Output Voltage
are the changes in output voltage when DI input changes state.
2.
The transceivers are put into shutdown by bringing RE High and DE Low simultaneously for at least 600ns. If the
control inputs are in this state for less than 50ns, the device is guaranteed not enter shutdown. If the enable inputs
are held in this state for at least 600ns the device is assured to be in shutdown. Note that the receiver and driver
enable times increase during shutdown
3.
Gauranteed by design and bench characterization.
7
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
FIGURE 3. DRIVER DC TEST CIRCUIT
R/2
DI
VOD
D
R/2
VCC
VOC
FIGURE 4. DRIVER COMMON MODE LOAD TEST
DE = 3.3V
375Ω
A/Y
DI = 0 or Vcc
D
60Ω
VOD
B/Z
375Ω
FIGURE 5. DRIVER SHORT CIRCUIT CURRENT LIMIT TEST
DE = 0 or Vcc
DI = 0 or Vcc
A/Y
IOSD
D
B/Z
100Ω
-7V to +12V V
8
VCM
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
FIGURE 6. DRIVER PROPAGATION DELAY TEST CIRCUIT
RL
54Ω
Y
DI
D
CL
50pF
VOD
Z
3.3V
FIGURE 7. DRIVER PROPAGATION DELAY TIMING DIAGRAM
Vcc
DI
Vcc/2
Vcc/2
0V
Z
t PLH
t PHL
VO 1/2VO
1/2VO
Y
VDIFF
VY – VZ
t DPLH
VO+
0V
VO–
t DPHL
90%
10%
tF
90%
10%
tR
t SKEW = |t DPLH - t DPHL|
FIGURE 8. DRIVER ENABLE AND DISABLE TIME TEST CIRCUIT 1
Y
0 or Vcc
DI
D
OUT
Z
GENERATOR
S1
CL = 50pF
50Ω
9
RL = 500Ω
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
FIGURE 9. DRIVER ENABLE DISABLE TIMING DIAGRAM 1
Vcc
DE
Vcc/2
0
tZH, tZH(SHDN)
OUT
0.25V
VOM = (VOL + Vcc)/2
t HZ
FIGURE 10. DRIVER ENABLE AND DISABLE TIME TEST CIRCUIT 2
Vcc
RL = 500Ω
Y
0 or Vcc
DI
OUT
Z
GENERATOR
S1
D
CL = 50pF
50Ω
10
0
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
FIGURE 11. DRIVER ENABLE AND DISABLE TIMING DIAGRAM 2
Vcc
Vcc/2
DE
0
tZL, tZL(SHDN)
t LZ
Vcc OUT
VOL
VOM = (VOL + Vcc)/2
0.25V
FIGURE 12. RECEIVER PROPAGATION DELAY TEST CIRCUIT
A
VID
B
R
RE
OUT
CL
15pF
FIGURE 13. RECEIVER PROPAGATION DELAY TIMING DIAGRAM
+1V
A
B
t PHL
t PLH
-1V
VOH
1.5V
VOL
OUT
11
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
FIGURE 14. RECEIVER ENABLE AND DISABLE TIMES TEST CIRCUIT
1.5V
S1
S3
B
-1.5V
R
A
S2
RE
GENERATOR
Vcc
1kΩ
CL= 15pF
50Ω
FIGURE 15. RECEIVER ENABLE AND DISABLE TIMING DIAGRAM 1
S1 is open, S2 is closed, S3 = 1.5V
3V
1.5V
RE
t ZH, t ZH(SHDN)
VOH
OUT
VOH /2
0V
FIGURE 16. RECEIVER ENABLE AND DISABLE TIMING DIAGRAM 2
S1 is closed, S2 is open, S3 = -1.5V
3V
1.5V
RE
t ZL,t ZL(SHDN)
0V
VCC
OUT
VOL= VCC /2
VOL
12
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
FIGURE 17. RECEIVER ENABLE AND DISABLE TIMING DIAGRAM 3
S1 is open, S2 is closed, S3 = 1.5V
3V
RE
1.5V
tHZ
0.25V
VOH
0V
OUT
FIGURE 18. RECEIVER ENABLE AND DISABLE TIMING DIAGRAM 4
S1 is closed, S2 is open, S3 = -1.5V
3V
RE
1.5V
0V
t LZ
VCC
OUT
0.25V
VOL
13
SP3495E-3497E
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
REV. 1.0.0
1.0 PRODUCT DESCRIPTION
The SP349xE high speed transceivers contain one driver and one receiver. The SP3495 is a half-duplex
design while the SP3496E and SP3497E are full-duplex designs. The control pins RE and DE feature a
hotswap capability allowing live insertion without spurious data transfer. Drivers are output short-circuit current
limited. Thermal-shutdown circuitry protects drivers against excessive power dissipation. When activited, the
thermal-shutdown circuitry forces the driver outptus into a high-impedance state.
Advanced Failsafe
The Receivers incorporate fail-safe circuitry, which guarantees a logic-high receiver output when the receiver
inputs are open or shorted, or when they are connected to a terminated transmission line with all drivers
disabled. In a terminated bus with all transmitters disabled the receivers differential input voltage is pulled to 0V
by the termination. The SP349xE interprets 0V differential as a logic high with a minimum 40mV noise margin.
HOT-SWAP CAPABILITY
When Vcc is first applied the SP349xE holds the driver enable and receiver enable inactive for approximately
10 microseconds. During power ramp-up other system IC’s may drive unpredictable values. Hot-swap
capability prevents the SP349xE from driving any output signal until power has stabilized. After the initial
power-up sequence, the hot-swap circuit becomes transparent and driver enable and receiver enable resume
their normal functions and timings
14
SP3495E-3497E
REV. 1.0.0
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
PACKAGE DIMENSIONS (14 PIN NSOIC)
15
SP3495E-3497E
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
PACKAGE DIMENSIONS (8 PIN NSOIC)
16
REV. 1.0.0
SP3495E-3497E
HIGH SPEED +3.3V RS-485/RS-422 TRANSCEIVERS WITH +/-15KV ESD PROTECTION AND ADVANCED FAILSAFE
REV. 1.0.0
REVISION HISTORY
DATE
REVISION
5/01/09
1.0.0
DESCRIPTION
Production Release.
NOTICE
EXAR Corporation reserves the right to make changes to the products contained in this publication in order to
improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any
circuits described herein, conveys no license under any patent or other right, and makes no representation that
the circuits are free of patent infringement. Charts and schedules contained here in 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 writing, 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 May 2009.
Send your technical inquiries with details to our e-mail hotline: uarttechsupport@exar.com.
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
17
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