EXAR XR5487E

XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD
AND +/-15KV ESD-PROTECTION
OCTOBER 2010
REV. 1.0.0
GENERAL DESCRIPTION
FEATURES
The XR5486E-XR5488E family of RS-485 devices
are designed for reliable, bidirectional communication
on multipoint bus transmission lines. Each device
contains one differential driver and one differential
receiver. XR5488E is a half-duplex device while the
other part numbers are full-duplex. All devices comply
with TIA/EIA-485 and TIA/EIA-422 standards. Leadfree and RoHS compliant packages are available for
all models.
These devices are ruggedized for use in harsh
operating conditions over the entire common mode
voltage range from -7V to +12V. Receivers are
specially designed to fail-safe to a logic high output
state if the inputs are left un-driven or shorted. All RS485 bus-pins are protected against severe ESD
events up to +/-15kV Air-Gap (IEC-61000-4-2), up to
+/-8kV Contact Discharge (IEC-61000-4-2) and up to
+/-15kV Human body Model. Drivers are protected
from excess current flow caused by bus contention or
output short-circuits by both an internal current limit
and a thermal-overload shutdown. Devices are rated
for Industrial (-40°C to +85°C) operating
temperatures. Receivers have exceptionally high
input impedance, which places only 1/8th the
standard load on a bus. Up to 256 transceivers may
coexist while preserving full signal margin.
All devices operate from a single 5.0V power supply
and draw negligible quiescent power. All versions
except the XR5487E may independently enable and
disable their driver and receiver and enter a low
power shutdown mode if both driver and receiver are
disabled. All outputs maintain high impedance in
shutdown or when powered-off.
• 5.0V Single Supply Operation
• High Speed up to 52Mbps
• Advanced Fail-safe Receiver Inputs
• Hot Swap glitch protection on control inputs
• Robust ESD Protection for RS-485 pins
■
+/-15kV Air-Gap Discharge
■
+/-15kV Human Body Model
■
+/-8kV Contact Discharge
• 1/8th Unit Load, 256 transceivers on bus
• Driver short circuit current limit and thermal
shutdown for overload protection
• Low Current 1μA shutdown mode (except
XR5487E)
• Industry standard package footprints
TYPICAL APPLICATIONS
• Motor Control
• Building Automation
• Security Systems
• Remote Utility Meter Reading
FIGURE 1. TYPICAL APPLICATION CIRCUIT
DE
DE
XR5488E
DI
XR5488E
B
B
STUB
RT
DI
RT
A
A
RO
RO
B
RE
A
XR5488E
A
XR5488E
B
DE
RE
RE DE
DI
RO
RE
DI
RO
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
REV. 1.0.0
FIGURE 2. PIN OUT ASSIGNMENT
8 VCC
RO
1
RE
2
DE
3
DI
4
5 GND
VCC
1
8
A
RO
2
7
B
DI
3
6
Z
GND
4
5
Y
NC
1
14 VCC
RO
2
13 NC
RE
3
DE
4
DI
5
GND
6
9
GND
7
8 NC
8-Pin NSOIC
Half Duplex
XR5488E
8-Pin NSOIC
Full Duplex
XR5487E
14-Pin NSOIC
Full Duplex
XR5486E
7 B
6 A
12 A
11 B
10 Z
Y
ORDERING INFORMATION
PART NUMBER
PACKAGE
OPERATING TEMPERATURE
RANGE
DEVICE STATUS
XR5486EID-F
14-pin Narrow SOIC
-40°C to +85°C
Active
XR5487EID-F
8-pin Narrow SOIC
-40°C to +85°C
Active
XR5488EID-F
8-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
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
PIN DESCRIPTIONS
Pin Assignments
PIN NUMBER
HALF DUPLEX
FULL DUPLEX
XR5488E
XR5487E
XR5486E
1
2
2
2
3
-
-
3
4
PIN NAME
TYPE
DESCRIPTION
RO
O
Receiver Output. When RE is low and if (AB) ≥ -50mV, 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
+5.0V power supply input. Bypass with
0.1uF capacitor.
-
8
12
A
I
Non-Inverting Receiver Input.
-
7
11
B
I
Inverting Receiver 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.
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
REV. 1.0.0
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 ≤ +7.0V
VCC
Input Voltage at control pins (RE, DE)
-0.3V to (VCC + 0.3V)
Driver input voltage (DI)
-0.3V to (VCC + 0.3V)
Receiver output voltage (RO)
-0.3V to (VCC + 0.3V)
Driver output voltage (A, B, Y and Z)
-8V to +13V
Receiver Input Voltage (A, B)
-8V to +13V
Storage Temperature Range
-65°C to + 150°C
Lead Temperature
+300°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 = +5.0V +/-0.25V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT VCC
= +5.0V AND 25OC.
SYMBOL
PARAMETERS
MIN
TYP
MAX
UNIT
CONDITIONS
S
DRIVER DC CHARACTERISTICS
Vcc
No Load
2.8
VOD
ΔVOD
Differential Driver Output
Change in Magnitude of Differential
Output
RL = 100Ω (RS-422), Figure 3
2.4
V
RL = 54Ω (RS-485), Figure 3
2.4
VCM = -7V, Figure 4
2.4
VCM = +12V, Figure 4
-0.20
0.20
RL = 100Ω (RS-422), Figure 3,
See note 1
-0.20
0.20
RL = 54Ω (RS-485), Figure 3, See
note 1
V
-0.20
0.20
-0.20
0.20
4
VCM = -7V, Figure 4, See
note 1
VCM = +12V, Figure 4, See note 1
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
UNLESS OTHERWISE NOTED: VCC = +5.0V +/-0.25V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT VCC
= +5.0V AND 25OC.
SYMBOL
VOC
PARAMETERS
MIN
TYP
Driver Common Mode Output
Voltage steady state
MAX
UNIT
CONDITIONS
S
3.0
V
Figure 3
Figure 3, See note 1
ΔVOC
Change in Magnitude of Common
Mode Output Voltage
-0.2
0.2
V
IOSD
Driver Short Circuit Current Limit
-250
250
mA
-7V ≤ VOUT ≤ +12V, Figure 5
Output Leakage Current (FullDuplex versions, Y and Z pins)
-75
125
μA
DE = 0V, RE = 0V, Vcc = 0V or 5V,
-7V ≤ VOUT ≤ +12V
V
Logic Input High
V
Logic Input Low
IOL
VIH
VIL
VHYS
IIN
Logic Input Thresholds (DI, DE, RE)
2.0
0.8
Driver Input Hysteresis
Logic Input Current (DI, DE and RE)
100
-1
1
mV
TA = 25°C
μA
0V ≤ IN ≤ +VCC, after first transition
Mbp
s
1/tUI, Duty Cycle 40 to 60%, Figure 4, CL = 50pF, RL = 54Ω.
DRIVER AC CHARACTERISTICS
freq
Data Signaling Rate
52
tPLH
Driver Propagation Delay (Low to
High)
4
25
ns
tPHL
Driver Propagation Delay (High to
Low)
4
25
ns
tR
Driver Rise Time
2
8
ns
tF
Driver Fall time
2
8
ns
+/-3
ns
Figures 6 and 7
|tPLH-tPHL|
Differential Pulse Skew
CL = 50pF, RL = 54Ω,
Figures 6 and 7
CL = 50pF, RL = 54Ω,
Figures 6 and 7
CL = 50pF, RL = 54Ω,
Figures 6 and 7
CL = 50pF, RL = 54Ω,
Figures 6 and 7
tZH
Driver Enable to Output High
60
ns
CL = 50pF, RL = 500Ω, Figures 8
and 9
tZL
Driver Enable to Output Low
60
ns
CL = 50pF, RL = 500Ω, Figures 10
and 11
tHZ
Driver Disable from Output High
60
ns
CL = 50pF, RL = 500Ω, Figures 8
and 9
tLZ
Driver Disable from Output Low
60
ns
CL = 50pF, RL = 500Ω, Figures 10
and 11
tZV
Shutdown to Driver Output Valid
1
μs
CL = 50pF, RL = 500Ω
600
ns
Notes 2, 3 and 4
tSHDN
Time to Shutdown
50
200
RECEIVER DC CHARACTERISTICS
5
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
REV. 1.0.0
UNLESS OTHERWISE NOTED: VCC = +5.0V +/-0.25V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT VCC
= +5.0V AND 25OC.
SYMBOL
IIN
PARAMETERS
MIN
Input Current (A, B pins)
-75
TYP
MAX
125
UNIT
CONDITIONS
S
μA
DE = 0, Vcc = 0 or 3.3V
VA or VB = 12V, other input 0V
VA or VB = -7V, other input 0V
VIH
VIL
Receiver Differential Thresholds
(VA - VB)
-50
-200
Receiver Input Hysteresis
VOH
Receiver Output Voltage High
VOL
Receiver Output Voltage Low
IOZ
High-Z Receiver Output Current
IOSS
Receiver Output Short Circuit
Current
RIN
Receiver Input Resistance
25
Vcc 1.2
mV
-7V ≤ VCM ≤
+12V, rising
mV
-7V ≤ VCM ≤
+12V, falling
mV
VCM = 0V
V
IOUT = -8mA, VID = -50mV
0.4
V
IOUT = 8mA, VID = -200mV
+/-1
μA
RE = Vcc, 0.40 ≤ VOUT ≤
+/-125
mA
0 ≤ VRO ≤ Vcc
96
KΩ
-7V ≤ VCM ≤
52
Mbp
s
1/tUI, Duty Cycle 40 to 60%,
+2.4V
+12V
RECEIVER AC CHARACTERISTICS
freq
Data Signaling Rate
tPLH
Receiver Propagation Delay (Low to
High)
20
30
ns
VID = +/-2V, CL = 15pF, Figures 12
and 13
tPHL
Receiver Propagation Delay (High
to Low)
20
30
ns
VID = +/-2V, CL = 15pF, Figures 12
and 13
skew
Receiver Propagation Delay Skew
CL = 15pF
+/-3
ns
VID = +/-2V, CL = 15pF, Figures 12
and 13
skew = |tPLH-tPHL|
tR
Receiver Output Rise Time
2
4
ns
CL = 15pF
tF
Receiver Output Fall Time
2
4
ns
CL = 15pF
tZH
Receiver Enable to Output High
40
ns
tZL
Receiver Enable to Output Low
40
ns
tHZ
Receiver Disable from Output High
40
ns
tLZ
Receiver Disable from Output Low
40
ns
tZH(SHDN)
Shutdown to Receiver Output Valid
High
1
μs
6
CL = 15pF, RL = 1kΩ,
Figures 14 and 15
CL = 15pF, RL = 1kΩ,
Figures 14 and 16
CL = 15pF, RL = 1kΩ,
Figures 14 and 17
CL = 15pF, RL = 1kΩ,
Figures 14 and 18
CL = 15pF, RL = 1kΩ, Figures 14
and 15
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
UNLESS OTHERWISE NOTED: VCC = +5.0V +/-0.25V WITH TA FROM -40OC TO +85OC. TYPICAL VALUES ARE AT VCC
= +5.0V AND 25OC.
SYMBOL
PARAMETERS
tZL(SHDN)
Shutdown to Receiver Output Valid
Low
tSHDN
Time to Shutdown
MIN
TYP
50
200
MAX
UNIT
S
CONDITIONS
1
μs
CL = 15pF, RL = 1kΩ, Figures 14
and 16
600
ns
Notes 2, 3 and 4
POWER REQUIREMENTS AND RECOMMENDED OPERATING CONDITIONS
Vcc
Supply Voltage
4.75
ICC1
Supply Current - Active Mode
ICC2
Supply Current - Shutdown Mode
TSD
Thermal Shutdown Temperature
165
°C
Thermal Shutdown Hysteresis
20
°C
+/-15
kV
Human Body Model
+/-15
kV
IEC-61000-4-2 Air Discharge
+/-8
kV
IEC-61000-4-2 Contact Discharge
+/-2
kV
Human Body Model
+/-200
V
Machine Model
ESD Protection at Pins A, B, Y and
Z pins
ESD Protection for RO, DI, DE and
RE pins
5.0
5.25
V
800
1500
μA
No Load, DE = RE = Vcc or 0V,
DI = 0V or Vcc
1
μA
DE = 0V, RE = Vcc, DI = Vcc or 0V
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.
Guaranteed by design and bench characterization.
4.
Except devices which do not have DE or RE inputs.
7
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
FIGURE 3. DRIVER DC TEST CIRCUIT
FIGURE 4. DRIVER COMMON MODE LOAD TEST
V
DE
Vcc/2
tZH, tZH(SHDN)
OUT
0.25
VOM = (VOL + Vcc)/2
t HZ
FIGURE 5. DRIVER SHORT CIRCUIT CURRENT LIMIT TEST
8
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
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
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
FIGURE 9. DRIVER ENABLE DISABLE TIMING DIAGRAM 1
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
REV. 1.0.0
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
FIGURE 11. DRIVER ENABLE AND DISABLE TIMING DIAGRAM 2
FIGURE 12. RECEIVER PROPAGATION DELAY TEST CIRCUIT
FIGURE 13. RECEIVER PROPAGATION DELAY TIMING DIAGRAM
+1V
A
B
t PHL
t PLH
-1V
VOH
1.5V
VOL
OUT
11
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
FIGURE 14. RECEIVER ENABLE AND DISABLE TIMES TEST CIRCUIT
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
REV. 1.0.0
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
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
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
REV. 1.0.0
1.0 PRODUCT DESCRIPTION
XR5486E-XR5488E is a family of advanced RS-485/RS-422 transceivers. Each contain one driver and one
receiver. The XR5488E is a half-duplex design while the XR5486E and XR5487E are full-duplex designs. All
devices operate from a single 5.0V power supply. These devices feature failsafe circuitry that guarantees a
logic-high receiver output when the inputs are open or shorted, or when they are connected to a terminated
transmission line with all drivers disabled. The control pins RE and DE feature a hotswap capability allowing
live insertion without spurious data transfer. The drivers are not slew rate limited making transmit speeds up to
52Mbps possible. 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
Ordinary RS-485 differential receivers will be in an indeterminate state whenever the data bus is not being
actively driven. The Advanced Failsafe feature of the XR5486E-XR5488E family 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 XR5486E-XR5488E family interprets 0V
differential as a logic high with a minimum 50mV noise margin while maintaining compliance with the EIA/TIA485 standard of +/-200mV.
HOT-SWAP CAPABILITY
When a micro-processor or other logic device undergoes its power-up sequence, its logic-outputs are typically
at high impedance. In this state they are unable to drive the DE and RE signals to a defined logic level. During
this period, noise, parasitic coupling or leakage from other devices could cause standard CMOS enable inputs
to drift to an incorrect logic level.
If circuit boards are inserted into an energized backplane (commonly called "live insertion" or "hot-swap")
power may suddenly be applied to all circuits. Without the hot-swap capability, this situation could improperly
enable the transceiver’s driver or receiver, driving invalid data onto shared busses and possibly causing driver
contention or device damage.
The XR5486E-XR5488E family contains a special power-on-reset circuit that holds the driver enable and
receiver enable inactive for approximately 10 microseconds. After this initial power-up sequence the hot-swap
circuit becomes transparent and driver enable and receiver enable resume their normal un-skewed functions
and timings.
+/-15kV ESD PROTECTION
ESD protection structures are incorporated on all pins to protect against electrostatic discharges encountered
during handling and assembly. The driver outputs and receiver inputs of the XR5486E-XR5488E family have
extra protection against static electricity. Exar uses state of the art structures to protect these pins against ESD
of +/-15kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown
and powered down. After an ESD event, the XR5486E-XR5488E family keep operating without latch-up or
damage.
ESD protection can be tested in various ways. The transmitter outputs and receiver inputs of the XR5486EXR5488E family are characterized for protection to the following limits:
■
+/-15kV using the Human Body Model
■
+/-8kV using the Contact Discharge Model
■
+/-15kV using the Airgap Discharge Model
ESD TEST CONDITIONS
ESD performance depends on a variety of conditions. Contact Exar for a reliability report that documents test
setup, methodology and results.
14
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
IEC 61000-4-2
The IEC 61000-4-2 standard covers ESD testing and performance of finished equipment. However, it does not
specifically refer to integrated circuits. The XR5486E-XR5488E family helps you design equipment to meet IEC
61000-4-2, without sacrificing board-space and cost for external ESD-protection components.
The major differences between tests done using the Human body model and IEC 61000-4-2 is a higher peak
current in IEC 61000-4-2. Series resistance is lower in the IEC 61000-4-2 model. Hence, the ESD withstand
voltage measured to IEC 61000-4-2 is generally lower than that of human body model.
The air-gap test involves approaching the device with a charged probe. The contact discharge method
connects the probe to the device before the probe is energized.
MACHINE MODEL
The machine model for ESD tests all pins using a 200pF storage capacitor and zero discharge resistance. The
objective is to emulate the stress caused when I/O pins are contacted by handling equipment during test and
assembly.
256 TRANSCEIVERS ON THE BUS
The standard RS-485 receiver input impedance is 12k Ohms (1 unit load). A standard driver can drive up to 32
unit loads. The XR5486E-XR5488E family of transceivers have only a 1/8th unit load receiver input impedance
of 96k Ohms, thereby allowing eight times as many, up to 256, transceivers to be connected in parallel on a
communication line. Any combination of these devices and other RS-485 transceivers up to a total of 32 unit
loads may be connected to the line.
LOW POWER SHUTDOWN MODE
Low-power shutdown mode is initiated by bringing both RE high and DE low simultaneously. While in shutdown
devices draw only 50nA of supply current. DE and RE may be tied together and driven by a single control
signal. Devices are guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the
inputs are in this state for at least 600ns, the parts are shutdown.
Enable times tZH and tZL apply when the part is not in low-power shutdown state. Enable times tZH(SHDN) and
tZL(SHDN) apply when the parts are shutdown. The drivers and receivers take longer to become enabled from
low-power shutdown tZH(SHDN) and tZL(SHDN) than from driver / receiver disable mode (tZH and tZL).
DRIVER OUTPUT PROTECTION
Two mechanisms prevent excessive output current and power dissipation caused by faults or by bus
contention. First, a driver current limit on the output stage provides immediate protection against short circuits
over the whole common-mode voltage range. Second, a thermal-shutdown circuit forces the driver outputs into
a high-impedance state if junction temperature becomes excessive.
LINE LENGTH
The RS-485/RS-422 standard covers line lengths up to 4000ft. Maximum achievable line length is a function of
signal attenuation and noise. Termination prevents signal reflections by eliminating the impedance mismatches
on a transmission line. Line termination is generaly used if rise and fall times are shorter than the round-trip
signal propagation time.
15
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
2.0 FUNCTION TABLES
TABLE 1: FULL DUPLEX 14 PIN XR5486E
TRANSMITTING
Inputs
Outputs
RE
DE
DI
Y
Z
X
1
1
1
0
X
1
0
0
1
0
0
X
High-Z
1
0
X
Shutdown
TABLE 2: FULL DUPLEX 8 PIN XR5487E
TRANSMITTING
Input
Outputs
DI
Y
Z
1
1
0
0
0
1
TABLE 3: HALF DUPLEX XR5488E
TRANSMITTING
Inputs
Outputs
RE
DE
DI
A
B
X
1
1
1
0
X
1
0
0
1
0
0
X
High-Z
1
0
X
Shutdown
16
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
TABLE 4: FULL DUPLEX 14 PIN XR5486E
RECEIVING
Inputs
Ouptut
RE
DE
VA - VB
RO
0
X
≥ -50mV
1
0
X
≤ -200mV
0
0
X
Open/Shorted
1
1
1
X
High-Z
1
0
X
Shutdown
TABLE 5: FULL DUPLEX 8 PIN XR5487E
RECEIVING
Inputs
Output
VA - VB
RO
≥ -50mV
1
≤ -200mV
0
Open/Shorted
1
TABLE 6: HALF DUPLEX XR5488E
RECEIVING
Inputs
Output
RE
DE
VA - VB
RO
0
X
≥ -50mV
1
0
X
≤ -200mV
0
0
X
Open/Shorted
1
1
1
X
High-Z
1
0
X
Shutdown
Note: Receiver inputs -200mV < VA - VB < -50mV should be considered indeterminate.
17
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
REV. 1.0.0
3.0 PRODUCT SELECTOR GUIDE
TABLE 7: SELECTION GUIDE
RECEIVER
SHUTDOWN AND DRIVER
ENABLE
PART
NUMBER
DUPLEX
DATA RATE
MBPS
XR5486E
Full
52
Yes
XR5487E
Full
52
XR5488E
Half
52
TRANS ON
BUS
FOOT-PRINT
Yes
256
SN75180
No
No
256
SN75179
Yes
Yes
256
SN75176
4.0 TYPICAL APPLICATIONS:
H alf-D uplex N etw ork
RT
STUB
RT
Bi-Directional Full-Duplex Network
18
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
Point to Multi-point with Repeater
Repeater
(optional)
19
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
PACKAGE DIMENSIONS (14 PIN NSOIC)
20
REV. 1.0.0
XR5486E-5488E
REV. 1.0.0
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
PACKAGE DIMENSIONS (8 PIN NSOIC)
21
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
22
REV. 1.0.0
XR5486E-5488E
ULTRA HIGH SPEED RS-485/RS-422 PROFIBUS TRANSCEIVERS WITH 1/8TH UNIT LOAD AND +/-15KV ESD-PROTECTION
REV. 1.0.0
REVISION HISTORY
DATE
REVISION
November 2009
Rev 1.0.0
October 2010
1.0.1
DESCRIPTION
Released datasheet.
Add PROFIBUS logo to front page
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 2010 EXAR Corporation
Datasheet October 2010.
Send your technical inquiries with details to our e-mail hotline: [email protected].
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
23