Maxim MAX3081E 15kvesd-protected,fail-safe,high-speed (10mbps) Datasheet

19-1800; Rev 0; 9/00
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
Features
♦ ESD Protection for RS-485 I/O Pins
±15kV, Human Body Model
♦ True Fail-Safe Receiver While Maintaining
EIA/TIA-485 Compatibility
♦ Enhanced Slew-Rate Limiting Facilitates
Error-Free Data Transmission
(MAX3080E–MAX3085E/MAX3089E)
♦ 1nA Low-Current Shutdown Mode (Except
MAX3081E/MAX3084E/MAX3087E)
♦ Pin-Selectable Full/Half-Duplex Operation
(MAX3089E)
♦ Phase Controls to Correct for Twisted-Pair
Reversal (MAX3089E)
♦ Allow Up to 256 Transceivers on the Bus
Applications
RS-422/RS-485 Communications
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Ordering Information
PART
TEMP. RANGE
MAX3080ECSD
0°C to +70°C
MAX3080ECPD
MAX3080EESD
MAX3080EEPD
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
14 SO
14 Plastic DIP
14 SO
14 Plastic DIP
Ordering Information continued at end of data sheet.
Selector Guide
Part
Half/Full
Duplex
Data
Rate
(Mbps)
SlewRate
Limited
LowPower
Shutdown
Receiver/
Driver
Enable
Quiescent Transceivers
Current
On
(µA)
Bus (µA)
Pin
Count
IndustryStandard
Pinout
MAX3080E
Full
0.115
Yes
Yes
Yes
375
256
14
75180
MAX3081E
Full
0.115
Yes
No
No
MAX3082E
Half
0.115
Yes
Yes
Yes
375
256
8
75179
375
256
8
75176
MAX3083E
Full
0.5
Yes
Yes
MAX3084E
Full
0.5
Yes
No
Yes
375
256
14
75180
No
375
256
8
MAX3085E
Half
0.5
Yes
75179
Yes
Yes
375
256
8
75176
MAX3086E
Full
10
MAX3087E
Full
10
No
Yes
Yes
375
256
14
75180
No
No
No
375
256
8
MAX3088E
Half
75179
10
No
Yes
Yes
375
256
8
75176
MAX3089E
Selectable
Selectable
Selectable
Yes
Yes
375
256
14
75180*
*Pin compatible with 75180, with additional features implemented using pins 1, 6, 8, and 13.
________________________________________________________________ Maxim Integrated Products
1
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAX3080E–MAX3089E
General Description
The MAX3080E–MAX3089E are ±15kV electrostatic discharge (ESD)-protected, high-speed transceivers for RS485/RS-422 communication that contain one driver and
one receiver. These devices feature fail-safe circuitry,
which guarantees a logic-high receiver output when the
receiver inputs are open or shorted. This means that the
receiver output will be a logic high if all transmitters on a
terminated bus are disabled (high impedance). The
MAX3080E/MAX3081E/MAX3082E feature reduced
slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing
error-free data transmission up to 115kbps. The
MAX3083E/MAX3084E/MAX3085E offer higher driver
output slew-rate limits, allowing transmit speeds up to
500kbps. The MAX3086E/MAX3087E/ MAX3088Es’ driver slew rates are not limited, making transmit speeds
up to 10Mbps possible. The MAX3089E’s slew rate is
selectable between 115kbps, 500kbps, and 10Mbps by
driving a selector pin with a single three-state driver. All
devices feature enhanced ESD protection. All transmitter
outputs and receiver inputs are protected to ±15kV
using the Human Body Model.
These transceivers typically draw 375µA of supply
current when unloaded, or when fully loaded with the drivers disabled.
All devices have a 1/8-unit-load receiver input impedance
that allows up to 256 transceivers on the bus. The
MAX3082E/MAX3085E/MAX3088E are intended for halfduplex communications, while the MAX3080E/MAX3081E/
MAX3083E/MAX3084E/MAX3086E/MAX3087E are
intended for full-duplex communications. The MAX3089E
is selectable between half-duplex and full-duplex operation. It also features independently programmable
receiver and transmitter output phase via separate pins.
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC) ............................................................+7V
Control Input Voltage (RE, DE)...................-0.3V to (VCC + 0.3V)
Special Input Voltage
(H/F, SRL, TXP, RXP)..............................-0.3V to (VCC + 0.3V)
Driver Input Voltage (DI).............................-0.3V to (VCC + 0.3V)
Driver Output Voltage (A, B, Y, Z)........................................±13V
Receiver Input Voltage (A, B) ..............................................±13V
Receiver Input Voltage, Full Duplex (A, B) ..........................±25V
Receiver Output Voltage (RO)....................-0.3V to (VCC + 0.3V)
Continuous Power Dissipation
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ...727mW
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
14-Pin Plastic DIP (derate 10.0mW/°C above +70°C) ....800mW
14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW
Operating Temperature Ranges
MAX308_EC_ _ ...................................................0°C to +70°C
MAX308_EE_ _ ................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
5
V
DRIVER
Differential Driver Output
(No Load)
VOD1
Differential Driver Output
VOD2
Change-in-Magnitude of
Differential Output Voltage
(Note 2)
∆VOD
Figure 5, R = 50Ω or R = 27Ω
0.2
V
VOC
Figure 5, R = 50Ω or R = 27Ω
3
V
Change-in-Magnitude of
Common-Mode Voltage (Note 2)
∆VOC
Figure 5, R = 50Ω or R = 27Ω
0.2
V
Input High Voltage
VIH1
DE, DI, RE, H/F, TXP, RXP
Input Low Voltage
VIL1
DI Input Hysteresis
VHYS
DE, DI, RE, H/F, TXP, RXP
MAX3080E–MAX3085E, and MAX3089E with
SRL = VCC or unconnected
Driver Common-Mode Output
Voltage
Figure 5
Figure 5, R = 50Ω (RS-422)
2.0
Figure 5, R = 27Ω (RS-485)
1.5
V
2.0
V
0.8
100
mV
IIN1
DE, DI, RE
Input High Voltage
Input Middle Voltage
IIN2
VIH2
VIM2
H/F, TXP, RXP, internal pulldown
SRL
SRL (Note 3)
Input Low Voltage
VIL2
SRL
SRL Input Current
IIN3
Input Current (A and B)
IIN4
DE = GND,
VCC = GND or 5.25V
VIN = 12V
125
VIN = -7V
-75
Output Leakage (Y and Z)
Full Duplex
IO
DE = GND,
VCC = GND or 5.25V
VIN = 12V
Driver Short-Circuit Output
Current (Note 4)
VOD1
SRL Input Current
2
±2
10
VCC - 0.8
0.4VCC
SRL = VCC
-7V ≤ VOUT ≤ VCC
0V ≤ VOUT ≤ 12V
0V ≤ VOUT ≤ VCC
40
V
V
0.8
V
-75
VIN = -7V
µA
0.6VCC
75
SRL = GND (Note 3)
V
125
-100
µA
µA
µA
-250
250
±25
_______________________________________________________________________________________
mA
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
MAX3080E–MAX3089E
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
-200
-125
-50
mV
0.4
mV
V
V
±1
µA
RECEIVER
Receiver Differential Threshold
Voltage
VTH
Receiver Input Hysteresis
Receiver Output High Voltage
Receiver Output Low Voltage
∆VTH
VOH
VOL
IO = -4mA, VID = -50mV
IO = 4mA, VID = -200mV
Three-State Output Current at
Receiver
IOZR
0.4V ≤ VO ≤ 2.4V
Receiver Input Resistance
RIN
-7V ≤ VCM ≤ 12V
96
Receiver Output Short-Circuit
Current
IOSR
0V ≤ VRO ≤ VCC
±7
-7V ≤ VCM ≤ 12V
25
VCC -1.5
kΩ
±95
mA
SUPPLY CURRENT
Supply Current
ICC
Supply Current in Shutdown
Mode
ESD Protection for Y, Z, A, B
ISHDN
No load,
RE = DI = GND
or VCC, SRL = VCC
DE = VCC
430
DE = GND
375
600
No load,
RE = DI = GND
or VCC, SRL = GND
DE = VCC
475
1000
DE = GND
420
800
DE = GND, V RE = VCC
0.001
10
Human Body Model
±15
900
µA
µA
µA
kV
Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referred to device
ground unless otherwise noted.
Note 2: ∆VOD and ∆VOC are the changes in VOD and VOC, respectively, when the DI input changes state.
Note 3: The SRL pin is internally biased to VCC / 2 by a 100kΩ/100kΩ resistor-divider. It is guaranteed to be VCC / 2 if left
unconnected.
Note 4: Maximum current level applies to peak current just prior to foldback-current limiting; minimum current level applies during
current limiting.
_______________________________________________________________________________________
3
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
SWITCHING CHARACTERISTICS—MAX3080E/MAX3081E/MAX3082E, and MAX3089E
with SRL = Unconnected
(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.)
PARAMETER
Driver Input-to-Output
SYMBOL
tDPLH
tDPHL
CONDITIONS
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Output Skew
| tDPLH - tDPHL |
tDSKEW
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Rise or Fall Time
tDR, tDF
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
MIN
TYP
MAX
500
2030
2600
500
2030
2600
-3
±200
ns
1320
2500
ns
667
ns
Maximum Data Rate
fMAX
Driver Enable to Output High
tDZH
Figures 8 and 10, CL = 100pF, S2 closed
3500
ns
Driver Enable to Output Low
tDZL
Figures 8 and 10, CL = 100pF, S1 closed
3500
ns
Driver Disable Time from Low
tDLZ
Figures 8 and 10, CL = 15pF, S1 closed
100
ns
Driver Disable Time from High
tDHZ
Figures 8 and 10, CL = 15pF, S2 closed
100
ns
Receiver Input to Output
| tRPLH - tRPHL | Differential
Receiver Skew
115
UNITS
kbps
tRPLH,
tRPHL
Figures 11 and 13; | VID | ≥ 2.0V;
rise and fall time of VID ≤ 15ns
127
200
ns
tRSKD
Figures 11 and 13; | VID | ≥ 2.0V;
rise and fall time of VID ≤ 15ns
3
±30
ns
Receiver Enable to Output Low
tRZL
Figures 6 and 12, CL = 100pF, S1 closed
20
50
ns
Receiver Enable to Output High
tRZH
Figures 6 and 12, CL = 100pF, S2 closed
20
50
ns
Receiver Disable Time from Low
tRLZ
Figures 6 and 12, CL = 100pF, S1 closed
20
50
ns
Receiver Disable Time from
High
tRHZ
Figures 6 and 12, CL = 100pF, S2 closed
20
50
ns
200
600
ns
Time to Shutdown
tSHDN
(Note 5)
50
Driver Enable from Shutdown to
Output High
tDZH(SHDN)
Figures 8 and 10, CL = 15pF, S2 closed
6000
ns
Driver Enable from Shutdown to
Output Low
tDZL(SHDN)
Figures 8 and 10, CL = 15pF, S1 closed
6000
ns
Receiver Enable from ShutdowntRZH(SHDN)
to-Output High
Figures 6 and 12, CL = 100pF, S2 closed
3500
ns
Receiver Enable from Shutdownto-Output Low
Figures 6 and 12, CL = 100pF, S1 closed
3500
ns
4
tRZL(SHDN)
_______________________________________________________________________________________
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.)
PARAMETER
Driver Input-to-Output
SYMBOL
tDPLH
tDPHL
CONDITIONS
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Output Skew
| tDPLH - tDPHL |
tDSKEW
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
Driver Rise or Fall Time
tDR, tDF
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
MIN
TYP
MAX
250
720
1000
250
720
1000
-3
±100
ns
530
750
ns
200
ns
Maximum Data Rate
fMAX
Driver Enable to Output High
tDZH
Figures 8 and 10, CL = 100pF, S2 closed
2500
ns
Driver Enable to Output Low
tDZL
Figures 8 and 10, CL = 100pF, S1 closed
2500
ns
Driver Disable Time from Low
tDLZ
Figures 8 and 10, CL = 15pF, S1 closed
100
ns
Driver Disable Time from High
tDHZ
Figures 8 and 10, CL = 15pF, S2 closed
100
ns
Receiver Input to Output
| tRPLH - tRPHL | Differential
Receiver Skew
500
UNITS
kbps
tRPLH,
tRPHL
Figures 11 and 13; | VID | ≥ 2.0V;
rise and fall time of VID ≤ 15ns
127
200
ns
tRSKD
Figures 11 and 13; | VID | ≥ 2.0V;
rise and fall time of VID ≤ 15ns
3
±30
ns
Receiver Enable to Output Low
tRZL
Figures 6 and 12, CL = 100pF, S1 closed
20
50
ns
Receiver Enable to Output High
tRZH
Figures 6 and 12, CL = 100pF, S2 closed
20
50
ns
Receiver Disable Time from Low
tRLZ
Figures 6 and 12, CL = 100pF, S1 closed
20
50
ns
Receiver Disable Time from
High
tRHZ
Figures 6 and 12, CL = 100pF, S2 closed
20
50
ns
200
600
ns
Time to Shutdown
tSHDN
(Note 5)
50
Driver Enable from
Shutdown-to-Output High
tDZH(SHDN)
Figures 8 and 10, CL = 15pF, S2 closed
4500
ns
Driver Enable from
Shutdown-to-Output Low
tDZL(SHDN)
Figures 8 and 10, CL = 15pF, S1 closed
4500
ns
Receiver Enable from
Shutdown-to-Output High
tRZH(SHDN)
Figures 6 and 12, CL = 100pF, S2 closed
3500
ns
Receiver Enable from
Shutdown-to-Output Low
tRZL(SHDN)
Figures 6 and 12, CL = 100pF, S1 closed
3500
ns
_______________________________________________________________________________________
5
MAX3080E–MAX3089E
SWITCHING CHARACTERISTICS—MAX3083E/MAX3084E/MAX3085E, and MAX3089E with
SRL = VCC
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
SWITCHING CHARACTERISTICS—MAX3086E/MAX3087E/MAX3088E, and MAX3089E with
SRL = GND
(VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.)
PARAMETER
Driver Input-to-Output
SYMBOL
tDPLH
tDPHL
CONDITIONS
MIN
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
TYP
MAX
34
60
34
60
UNITS
ns
Driver Output Skew
| tDPLH - tDPHL |
tDSKEW
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
-2.5
±10
ns
Driver Rise or Fall Time
tDR, tDF
Figures 7 and 9, RDIFF = 54Ω,
CL1 = CL2 = 100pF
14
25
ns
Maximum Data Rate
fMAX
Driver Enable to Output High
tDZH
Figures 8 and 10, CL = 100pF, S2 closed
150
ns
Driver Enable to Output Low
tDZL
Figures 8 and 10, CL = 100pF, S1 closed
150
ns
Driver Disable Time from Low
tDLZ
Figures 8 and 10, CL = 15pF, S1 closed
100
ns
tDHZ
Figures 8 and 10, CL = 15pF, S2 closed
100
ns
Driver Disable Time from High
Receiver Input-to-Output
| tRPLH - tRPHL | Differential
Receiver Skew
10
Mbps
tRPLH,
tRPHL
Figures 11 and 13; | VID | ≥ 2.0V;
rise and fall time of VID ≤ 15ns
106
150
ns
tRSKD
Figures 11 and 13; | VID | ≥ 2.0V;
rise and fall time of VID ≤ 15ns
0
±10
ns
Receiver Enable to Output Low
tRZL
Figures 6 and 12, CL = 100pF, S1 closed
20
50
ns
Receiver Enable to Output High
tRZH
Figures 6 and 12, CL = 100pF, S2 closed
20
50
ns
Receiver Disable Time from Low
tRLZ
Figures 6 and 12, CL = 100pF, S1 closed
20
50
ns
Receiver Disable Time from
High
tRHZ
Figures 6 and 12, CL = 100pF, S2 closed
20
50
ns
200
600
ns
Time to Shutdown
tSHDN
(Note 5)
50
Driver Enable from
Shutdown-to-Output High
tDZH(SHDN)
Figures 8 and 10, CL = 15pF, S2 closed
250
ns
Driver Enable from
Shutdown-to-Output Low
tDZL(SHDN)
Figures 8 and 10, CL = 15pF, S1 closed
250
ns
Receiver Enable from
Shutdown-to-Output High
tRZH(SHDN)
Figures 6 and 12, CL = 100pF, S2 closed
3500
ns
Receiver Enable from
Shutdown-to-Output Low
tRZL(SHDN)
Figures 6 and 12, CL = 100pF, S1 closed
3500
ns
Note 5: The device is put into shutdown by bringing RE high and DE low. If the enable inputs are in this state for less than 50ns, the
device is guaranteed not to enter shutdown. If the enable inputs are in this state for at least 600ns, the device is guaranteed
to have entered shutdown.
6
_______________________________________________________________________________________
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
A
DE = GND
B
375
A
B: MAX3080E–MAX3085E,
MAX3089E WITH
SRL = OPEN OR VCC
B
325
0
20
40
60
MAX3080/3089 TOC-3
MAX3080/3089 TOC-2
3
2
1
0
5
4
3
2
1
5
4
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
OUTPUT HIGH VOLTAGE (V)
SHUTDOWN CURRENT
vs. TEMPERATURE
RECEIVER OUTPUT LOW VOLTAGE
vs. TEMPERATURE
RECEIVER OUTPUT HIGH VOLTAGE
vs. TEMPERATURE
16
14
12
10
8
6
0.50
IRO = 8mA
0.45
4
45
0.40
IRO = 8mA
4.4
OUTPUT VOLTAGE (V)
18
OUTPUT LOW VOLTAGE (V)
MAX3080/3089 TOC-1
20
0.35
0.30
0.25
0.20
0
0
20
40
60
100
80
4.1
40
3.8
0.10
-60 -40 -20
42
3.9
0.15
2
43
-60 -40
-20
0
20
40
60
80
-60 -40
100
-20
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
RECEIVER PROPAGATION DELAY
(500kbps MODE) vs. TEMPERATURE
RECEIVER PROPAGATION DELAY
(10Mbps MODE) vs. TEMPERATURE
DRIVER PROPAGATION DELAY
(115kbps MODE) vs. TEMPERATURE
CLOAD = 100pF
135
130
125
120
112
CLOAD = 100pF
110
PROPAGATION DELAY (ns)
MAX3080/3089 TOC-7
140
108
106
104
102
100
98
2.20
MAX3080/3089 TOC-9
SHUTDOWN CURRENT (nA)
0
100
80
10
0
0
-60 -40 -20
15
5
10
300
PROPAGATION DELAY (ns)
20
Rt = 54Ω
2.15
PROPAGATION DELAY (µs)
350
30
20
MAX3080/3089 TOC-4
400
40
25
MAX3080/3089 TOC-5
425
50
30
OUTPUT CURRENT (mA)
450
60
MAX3080/3089 TOC-8
475
A: MAX3086E/MAX3087E/MAX3088E,
MAX3089E WITH
SRL = GND
DE = VCC
OUTPUT CURRENT (mA)
500
MAX3080/3089 TOC-16
NO-LOAD SUPPLY CURRENT (µA)
525
OUTPUT CURRENT
vs. RECEIVER OUTPUT HIGH VOLTAGE
OUTPUT CURRENT
vs. RECEIVER OUTPUT LOW VOLTAGE
NO-LOAD SUPPLY CURRENT
vs. TEMPERATURE
2.10
2.05
2.00
1.95
96
115
94
-60 -40 -20
0
20
40
TEMPERATURE (°C)
60
80
100
1.90
-60 -40 -20
0
20
40
TEMPERATURE (°C)
60
80
100
-60 -40 -20
0
20
40
60
80
100
TEMPERATURE (°C)
_______________________________________________________________________________________
7
MAX3080E–MAX3089E
Typical Operating Characteristics
(VCC = +5V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VCC = +5V, TA = +25°C, unless otherwise noted.)
760
720
680
640
600
50
Rt = 54Ω
1.89
45
40
35
30
520
20
-60 -40 -20
0
20
40
60
80
100
1.87
1.86
1.85
1.83
0
-60 -40 -20
20
60
40
80
100
-60 -40 -20
0
40
20
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
DRIVER OUTPUT CURRENT
vs. DIFFERENTIAL OUTPUT VOLTAGE
OUTPUT CURRENT vs.
DRIVER OUTPUT LOW VOLTAGE
OUTPUT CURRENT vs.
DRIVER OUTPUT HIGH VOLTAGE
0.1
100
80
60
40
2
3
4
DIFFERENTIAL OUTPUT VOLTAGE (V)
5
-60
-50
-40
-30
-10
0
1
-70
-20
20
0 01
MAX3080/3089 TOC-27
OUTPUT CURRENT (mA)
1
-90
-80
OUTPUT CURRENT (mA)
10
120
100
-100
MAX3080-25
140
MAX3080 TOC-12
100
0
1.88
1.84
25
560
8
1.90
OUTPUT VOLTAGE (V)
800
Rt = 54Ω
55
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
MAX3080/3089 TOC-11
840
60
PROPAGATION DELAY (ns)
Rt = 54Ω
880
PROPAGATION DELAY (ns)
MAX3080/3089 TOC-10
920
DRIVER PROPAGATION DELAY
(10Mbps MODE) vs. TEMPERATURE
MAX3080/3089 TOC-13
DRIVER PROPAGATION DELAY
(500kbps MODE) vs. TEMPERATURE
OUTPUT CURRENT (mA)
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
0
0
2
4
6
8
OUTPUT LOW VOLTAGE (V)
10
12
-8
-6
-4
-2
0
2
OUTPUT HIGH VOLTAGE (V)
_______________________________________________________________________________________
4
6
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
(VCC = +5V, TA = +25°C, unless otherwise noted.)
RECEIVER PROPAGATION DELAY
MAX3086E/MAX3087E/MAX3088E AND MAX3089E
WITH SRL = GND
RECEIVER PROPAGATION DELAY
MAX3080E–MAX3085E AND MAX3089E
WITH SRL = OPEN OR VCC
MAX3080/3089 TYP 18
MAX3080/3089 TYP 17
VA - VB
2V/div
VA - VB
2V/div
RO
5V/div
RO
5V/div
50ns/div
50ns/div
DRIVER PROPAGATION DELAY
MAX3080E/MAX3081E/MAX3082E AND MAX3089E
WITH SRL = OPEN
MAX3080/3089 TYP 20
DI
5V/div
VY - VZ
2.5V/div
2µs/div
DRIVER PROPAGATION DELAY
MAX3086E/MAX3087E/MAX3088E AND MAX3089E
WITH SRL = GND
DRIVER PROPAGATION DELAY
MAX3083E/MAX3084E/MAX3085E AND MAX3089E
WITH SRL = VCC
MAX3080/3089 TYP 22
MAX3080/3089 TYP 21
DI
5V/div
VY - VZ
2.5V/div
500ns/div
DI
5V/div
VY - VZ
2 5V/div
50ns/div
_______________________________________________________________________________________
9
MAX3080E–MAX3089E
Typical Operating Characteristics (continued)
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
Pin Description
PIN
MAX3080E MAX3081E MAX3082E
MAX3083E MAX3084E MAX3085E
MAX3086E MAX3087E MAX3088E
FULL-DUPLEX
DEVICES
10
MAX3089E
HALFDUPLEX
DEVICES
FULLDUPLEX
MODE
HALFDUPLEX
MODE
NAME
FUNCTION
—
—
—
1
1
H/F
Half/Full-Duplex Selector Pin. Connect H/F to VCC for halfduplex mode; connect to GND or leave unconnected for
full-duplex mode.
2
2
1
2
2
RO
Receiver Output. When RE is low and if A - B ≥ -50mV,
RO will be high; if A - B ≤ -200mV, RO will be low.
3
—
2
3
3
RE
Receiver Output Enable. Drive RE low to enable RO; RO
is high impedance when RE is high. Drive RE high and
DE low to enter low-power shutdown mode.
4
—
3
4
4
DE
Driver Output Enable. Drive DE high to enable driver outputs. These outputs are high impedance when DE is low.
Drive RE high and DE low to enter low-power shutdown
mode.
5
3
4
5
5
DI
Driver Input. With DE high, a low on DI forces noninverting
output low and inverting output high. Similarly, a high on DI
forces non-inverting output high and inverting output low.
—
—
—
6
6
SRL
Slew-Rate-Limit Selector Pin. Connect SRL to GND for
10Mbps communication rate; connect to VCC for
500kbps communication rate. Leave unconnected for
115kbps communication rate.
6, 7
4
5
7
7
GND
Ground
—
—
—
8
8
TXP
Transmitter Phase. Connect TXP to GND, or leave floating
for normal transmitter phase/polarity. Connect to VCC to
invert the transmitter phase/polarity.
9
5
—
9
—
Y
Noninverting Driver Output
—
—
—
—
9
Y
Noninverting Receiver Input and Noninverting Driver
Output*
10
6
—
10
—
Z
Inverting Driver Output
—
—
—
—
10
Z
Inverting Receiver Input and Inverting Driver Output*
11
7
—
11
—
B
Inverting Receiver Input
—
—
—
—
11
B
Receiver Input Resistors*
—
—
7
—
—
B
Inverting Receiver Input and Inverting Driver Output
______________________________________________________________________________________
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
PIN
MAX3080E MAX3081E MAX3082E
MAX3083E MAX3084E MAX3085E
MAX3086E MAX3087E MAX3088E
FULL-DUPLEX
DEVICES
MAX3089E
NAME
HALFDUPLEX
DEVICES
FULLDUPLEX
MODE
HALFDUPLEX
MODE
FUNCTION
12
8
—
12
—
A
Noninverting Receiver Input
—
—
—
—
12
A
Receiver Input Resistors*
—
—
6
—
—
A
Noninverting Receiver Input and Noninverting Driver
Output
—
—
—
13
13
RXP
Receiver Phase. Connect RXP to GND, or leave unconnected for normal transmitter phase/polarity. Connect to
VCC to invert the receiver phase/polarity:
14
1
8
14
14
VCC
Positive Supply 4.75V ≤ VCC ≤ 5.25V
1, 8, 13
—
—
—
—
N.C.
Not Connected. Not internally connected.
*(MAX3089E only) In half-duplex mode, the driver outputs serve as receiver inputs. The full-duplex receiver inputs (A and B) will still
have a 1/8-unit load, but are not connected to the receiver.
Function Tables
MAX3080E/MAX3083E/MAX3086E
MAX3081E/MAX3084E/MAX3087E
TRANSMITTING
TRANSMITTING
INPUTS
INPUT
OUTPUTS
OUTPUTS
RE
DE
DI
Z
Y
DI
Z
Y
X
1
1
0
1
1
0
1
0
0
1
0
X
1
0
1
0
0
X
High-Z
1
0
X
High-Z
Shutdown
RECEIVING
RECEIVING
INPUTS
OUTPUT
INPUTS
OUTPUT
A-B
RO
≥ -0.05V
1
RE
DE
A-B
RO
≤ -0.2V
0
0
X
≥ -0.05V
1
Open/shorted
1
0
X
≤ -0.2V
0
0
X
Open/shorted
1
1
1
X
High-Z
1
0
X
Shutdown
X = Don’t care
Shutdown mode, driver and receiver outputs high impedance
______________________________________________________________________________________
11
MAX3080E–MAX3089E
Pin Description (continued)
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
Function Tables (continued)
MAX3082E/MAX3085E/MAX3088E
MAX3089E
TRANSMITTING
TRANSMITTING
INPUTS
INPUTS
OUTPUTS
OUTPUTS
RE
DE
DI
B/Z
A/Y
TXP
RE
DE
DI
Z
Y
X
1
1
0
1
0
X
1
1
0
1
X
1
0
1
0
0
X
1
0
1
0
0
0
X
High-Z
High-Z
1
X
1
1
1
0
1
0
X
1
X
1
0
0
1
X
0
0
X
High-Z
High-Z
X
1
0
X
Shutdown
Shutdown
RECEIVING
INPUTS
OUTPUT
RE
DE
A-B
RO
0
X
≥ -0.05V
1
0
X
≤ -0.2V
0
H/F
RXP
RE
DE
A-B
Y-Z
RO
0
X
Open/shorted
1
0
0
0
X
≥ -0.05V
X
1
1
1
X
High-Z
0
0
0
X
≤ -0.2V
X
0
1
0
X
Shutdown
0
1
0
X
≥ -0.05V
X
0
0
1
0
X
≤ -0.2V
X
1
1
0
0
0
X
≥ -0.05V
1
1
0
0
0
X
≤ -0.2V
0
1
1
0
0
X
≥ -0.05V
0
1
1
0
0
X
≤ -0.2V
1
0
0
0
X
Open/
shorted
X
1
1
0
0
0
X
Open/
shorted
1
0
1
0
X
Open/
shorted
X
0
1
1
0
0
X
Open/
shorted
0
X
X
1
1
X
X
High-Z
X
X
1
0
X
X
Shutdown
X = Don’t care
Shutdown mode, driver and receiver outputs high impedance
12
RECEIVING
INPUTS
OUTPUT
______________________________________________________________________________________
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
VCC
DE
4
N.C. 1
13 N.C.
RE 3
12 A
DE 4
11 B
DI 5
10 Z
D
GND 6
GND 7
9
Y
8
N.C.
VCC RE
0.1µF
14
14 VCC
R
RO 2
9
5
DI
Y
MAX3080E
MAX3083E
MAX3086E
Rt
D
MAX3080E–MAX3089E
TOP VIEW
RO
R
10
Z
12
2
RO
R
A
Rt
D
11
DI
B
NC
1, 8, 13
3
DIP/SO
6, 7 GND
GND
RE
DE
Figure 1. MAX3080E/MAX3083E/MAX3086E Pin Configuration and Typical Full-Duplex Operating Circuit
TOP VIEW
0.1µF
VCC
MAX3081E
MAX3084E
MAX3087E
VCC 1
5 Y
8
A
RO 2
7
B
DI 3
6
Z
VCC 1
GND 4
R
D
5
Y
DI
3
Rt
D
R
6 Z
RO
8 A
RO
2
R
Rt
D
7
DI
B
DIP/SO
4 GND
GND
Figure 2. MAX3081E/MAX3084E/MAX3087E Pin Configuration and Typical Full-Duplex Operating Circuit
TOP VIEW
0.1µF
RO
1
R
8
VCC
RO
RE 2
7
B
RE
DE 3
6
A
DE
5
GND
DI
DI 4
D
1
8
R
7 B
3
6 A
5
D
DI
B
Rt
D
DE
VCC
2
4
MAX3082E
MAX3085E
MAX3088E
Rt
A
GND
RO
R
RE
DIP/SO
NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS. REFER TO PINS A AND B WHEN DE IS HIGH.
Figure 3. MAX3082E/MAX3085E/MAX3088E Pin Configuration and Typical Half-Duplex Operating Circuit
______________________________________________________________________________________
13
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
Detailed Description
The MAX3080E–MAX3089E high-speed transceivers for
RS-485/RS-422 communication contain one driver and
one receiver. These devices feature 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 (see the Fail-Safe section). The
MAX3080E/MAX3081E/MAX3082E feature reduced
slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing
error-free data transmission up to 115kbps (see the
Reduced EMI and Reflections section). The
MAX3083E/MAX3084E/MAX3085E offer higher driver
output slew-rate limits, allowing transmit speeds up to
500kbps. The MAX3086E/MAX3087E/MAX3088E’s driver slew rates are not limited, making transmit speeds
up to 10Mbps possible. The MAX3089E’s slew rate is
selectable between 115kbps, 500kbps, and 10Mbps
by driving a selector pin with a three-state driver.
The MAX3082E/MAX3085E/MAX3088E are half-duplex
transceivers, while the MAX3080E/MAX3081E/
MAX3083E/MAX3084E/MAX3086E/MAX3087E are fullduplex transceivers. The MAX3089E is selectable
between half- and full-duplex communication by driving
a selector pin high or low, respectively.
All of these parts operate from a single +5V supply.
Drivers are output short-circuit current limited. Thermal
shutdown circuitry protects drivers against excessive
power dissipation. When activated, the thermal shutdown circuitry places the driver outputs into a highimpedance state.
Receiver Input Filtering
The receivers of the MAX3080E–MAX3085E, and the
MAX3089E when operating in 115kbps or 500kbps
mode, incorporate input filtering in addition to input
hysteresis. This filtering enhances noise immunity with
differential signals that have very slow rise and fall
times. Receiver propagation delay increases by 20%
due to this filtering.
Fail-Safe
The MAX3080E family guarantees a logic-high receiver
output when the receiver inputs are shorted or open, or
when they are connected to a terminated transmission
line with all drivers disabled. This is done by setting the
receiver threshold between -50mV and -200mV. If the
differential receiver input voltage (A-B) is greater than
or equal to -50mV, RO is logic high. If A-B is less than
or equal to -200mV, RO is logic low. In the case of a
terminated bus with all transmitters disabled, the
receiver’s differential input voltage is pulled to 0V by
14
the termination. With the receiver thresholds of the
MAX3080E family, this results in a logic high with a
50mV minimum noise margin. Unlike previous fail-safe
devices, the -50mV to -200mV threshold complies with
the ±200mV EIA/TIA-485 standard.
MAX3089E Programming
The MAX3089E has several programmable operating
modes. Transmitter rise and fall times are programmable between 2500ns, 750ns, and 25ns, resulting in
maximum data rates of 115kbps, 500kbps, and
10Mbps, respectively. To select the desired data rate,
drive SRL to one of three possible states by using a
three-state driver, by connecting it to VCC or GND, or
by leaving it unconnected. For 115kbps operation, set
the three-state device in high-impedance mode or
leave SRL unconnected. For 500kbps operation, drive
SRL high or connect it to VCC. For 10Mbps operation,
drive SRL low or connect it to GND. SRL can be
changed during operation without interrupting data
communications.
Occasionally, twisted-pair lines are connected backward from normal orientation. The MAX3089E has two
pins that invert the phase of the driver and the receiver
to correct for this problem. For normal operation, drive
TXP and RXP low, connect them to ground, or leave
them unconnected (internal pulldown). To invert the driver phase, drive TXP high or connect it to V CC. To
invert the receiver phase, drive RXP high or connect it
to V CC . Note that the receiver threshold is positive
when RXP is high.
The MAX3089E can operate in full- or half-duplex
mode. Drive the H/F pin low, leave it unconnected
(internal pulldown), or connect it to GND for full-duplex
operation, and drive it high for half-duplex operation. In
full-duplex mode, the pin configuration of the driver and
receiver is the same as that of a MAX3080E (Figure 4).
In half-duplex mode, the receiver inputs are switched to
the driver outputs, connecting outputs Y and Z to inputs
A and B, respectively. In half-duplex mode, the internal
full-duplex receiver input resistors are still connected to
pins 11 and 12.
±15kV ESD Protection
As with all Maxim devices, 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
MAX3080E–MAX3089E family have extra protection
against static electricity. Maxim’s engineers have
developed state-of-the-art structures to protect these
pins against ESD of ±15kV without damage.
______________________________________________________________________________________
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
MAX3080E–MAX3089E
VCC
RE
MAX3089E
A
RD
TOP VIEW
B
H/F
1
14 V CC
RO 2
RE 3
RXP
13 RXP
MAX3089E
12 A
DE 4
11 B
DI 5
10 Z
SRL 6
9
Y
GND 7
8
TXP
H/F
Z
TXP
DIP/SO
Y
DI
NOTE: SWITCH POSITIONS
INDICATED FOR H/F = GND
GND
DE
SRL
Figure 4. MAX3089E Pin Configuration and Functional Diagram
Y
TEST POINT
RECEIVER
OUTPUT
CRL
15pF
R
VOD
R
1k
VCC
S1
1k
VOC
S2
Z
Figure 5. Driver DC Test Load
Figure 6. Receiver Enable/Disable Timing Test Load
The ESD-protected pins are tested with reference to the
ground pin in a powered-down condition. They are tested to ±15kV using the Human Body Model.
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the test device
through a 1.5kΩ resistor.
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 14a shows the Human Body Model, and Figure
14b shows the current waveform it generates when dis-
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. All pins require this protec-
______________________________________________________________________________________
15
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
3V
DE
DI
CL1
Y
RDIFF
VOD2
VCC
S1
500Ω
OUTPUT
UNDER TEST
Z
CL
CL2
S2
Figure 7. Driver Timing Test Circuit
Figure 8. Driver Enable and Disable Timing Test Load
5V
DI
5V
1.5V
0
DE
1 5V
tDPHL
tDPLH
1/2 VO
1 5V
tDZL(SHDN), tDZL
Z
tDLZ
Y, Z
VO
2.3V OUTPUT NORMALLY LOW
VOL
Y
1/2 VO
VO
VDIFF
0
-VO
1 5V
0
10%
tDR
VDIFF = V (Y) - V (Z)
OUTPUT NORMALLY HIGH
Y, Z
90%
90%
VOH -0.5V
2 3V
10%
0
tDZH(SHDN), tDZH
tDF
tSKEW = | tDPLH - tDPHL |
Figure 9. Driver Propagation Delays
VOL +0.5V
tDHZ
Figure 10. Driver Enable and Disable Times (Except
MAX3081E/MAX3084E/MAX3087E)
5V
RE
1 5V
1 5V
0
RO
VOH
VOL
1V
A
-1V
B
1.5V
OUTPUT
tRPHL
tRPLH
1.5V
tRZL(SHDN), tRZL
tRLZ
VCC
RO
1.5V OUTPUT NORMALLY LOW
RO
1.5V
INPUT
VOL + 0 5V
OUTPUT NORMALLY HIGH
VOH - 0.5V
0
tRZH(SHDN), tRZH
Figure 11. Receiver Propagation Delays
16
tRHZ
Figure 12. Receiver Enable and Disable Times (Except
MAX3081E/MAX3084E/MAX3087E)
______________________________________________________________________________________
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
CHARGE-CURRENT
LIMIT RESISTOR
MAX3080E–MAX3089E
RC
1MΩ
RD
1500Ω
DISCHARGE
RESISTANCE
B
R
RECEIVER
OUTPUT
A
Ir
Cs
100pF
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 14a. Human Body ESD Test Model
Figure 13. Receiver Propagation Delay Test Circuit
IP 100%
90%
HIGHVOLTAGE
DC
SOURCE
MAX3080/3089 FIG-14
VID
ATE
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
AMPERES
36.8%
20dB/div
10%
0
0
tRL
TIME
tDL
CURRENT WAVEFORM
0Hz
100kHz/div
1MHz
Figure 15. Driver Output Waveform and FFT Plot of
MAX3086E/MAX3087E/MAX3088E, and MAX3089E with
SRL = GND, Transmitting a 20kHz Signal
20dB/div
MAX3080/3089 FIG-16
MAX3080/3089 FIG-15
Figure 14b. Human Body Current Waveform
20dB/div
0Hz
100kHz/div
Figure 16. Driver Output Waveform and FFT Plot of
MAX3083E/MAX3084E/MAX3085E, and MAX3089E
with SRL = VCC, Transmitting a 20kHz Signal
1MHz
0Hz
100kHz/div
1MHz
Figure 17. Driver Output Waveform and FFT Plot of
MAX3080E/MAX3081E/MAX3082E, and MAX3089E
with SRL = Unconnected, Transmitting a 20kHz Signal
______________________________________________________________________________________
17
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
MAX3080/3089 FIG 18
MAX3080E/MAX3081E/MAX3083E/
MAX3084E/MAX3086E/MAX3087E/
MAX3089E (FULL DUPLEX)
DI
5V/div
VA - VB
1V/div
RO
5V/div
A
RO
RE
R
120Ω
B
DATA IN
DE
Z
DI
D
120Ω
Y
DATA OUT
NOTE: RE AND DE ON MAX3080E/MAX3083E/MAX3086E/MAX3089E ONLY.
5µs/div
Figure 18. Line Repeater for MAX3080E/MAX3081E/MAX3083E/
MAX3084E/MAX3086E/MAX3087E, and MAX3089E in Full-Duplex
Mode
Figure 19. MAX3080E/MAX3081E/MAX3082E, and MAX3089E
with SRL = Unconnected, System Differential Voltage at 50kHz
Driving 4000ft of Cable
during test and assembly. All pins require this protection, not just RS-485 inputs and outputs.
Figure 17’s high-frequency harmonic components are
even lower.
In general, a transmitter’s rise time relates directly to the
length of an unterminated stub, which can be driven with
only minor waveform reflections. The following equation
expresses this relationship conservatively:
Length = tRISE / (10 x 1.5ns/ft)
Applications Information
256 Transceivers on the Bus
The standard RS-485 receiver input impedance is 12kΩ
(one-unit load), and the standard driver can drive up to
32 unit loads. The MAX3080E family of transceivers
have a 1/8-unit-load receiver input impedance (96kΩ),
allowing up to 256 transceivers to be connected in parallel on one communication line. Any combination of
these devices and/or other RS-485 transceivers with a
total of 32 unit loads or less can be connected to the
line.
Reduced EMI and Reflections
The MAX3080E–MAX3085E, and MAX3089E with SRL =
VCC or unconnected, are slew-rate limited, minimizing
EMI and reducing reflections caused by improperly terminated cables. Figure 15 shows the driver output
waveform and its Fourier analysis of a 20kHz signal
transmitted by a MAX3086E/MAX3087E/MAX3088E,
and MAX3089E with SRL = GND. High-frequency harmonic components with large amplitudes are evident.
Figure 16 shows the same signal displayed for a
MAX3083E/MAX3084E/MAX3085E, and MAX3089E with
SRL = VCC), transmitting under the same conditions.
Figure 16’s high-frequency harmonic components are
much lower in amplitude, compared with Figure 15’s,
and the potential for EMI is significantly reduced. Figure
17 shows the same signal displayed for a MAX3080E/
MAX3081E/MAX3082E, and MAX3089E with SRL =
unconnected, transmitting under the same conditions.
18
where tRISE is the transmitter’s rise time.
For example, the MAX3080E’s rise time is typically
1320ns, which results in excellent waveforms with a stub
length up to 90 feet. A system can work well with longer
unterminated stubs, even with severe reflections, if the
waveform settles out before the UART samples them.
Low-Power Shutdown Mode
(Except MAX3082E/MAX3085E/MAX3088E)
Low-power shutdown mode is initiated by bringing both
RE high and DE low. In shutdown, the devices typically
draw only 1nA of supply current.
RE and DE may be driven simultaneously; the parts 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 guaranteed to enter
shutdown.
Enable times t ZH and t ZL in the Switching Characteristics tables assume the part was not in a lowpower shutdown state. Enable times tZH(SHDN) and
tZL(SHDN) assume the parts were shut down. It takes
drivers and receivers longer to become enabled from
low-power shutdown mode (tZH(SHDN), tZH(SHDN)) than
from driver/receiver-disable mode (tZH, tZL).
______________________________________________________________________________________
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
DI
5V/div
DI
5V/div
VA - VB
1V/div
VA - VB
1V/div
RO
5V/div
RO
5V/div
1µs/div
2µs/div
Figure 20. MAX3083E/MAX3084E/MAX3085E, and MAX3089E
with SRL = VCC, System Differential Voltage at 50kHz Driving
4000ft of Cable
Figure 21. MAX3086E/MAX3087E/MAX3088E, and MAX3089E
with SRL = GND, System Differential Voltage at 200kHz Driving
4000ft of Cable
120Ω
120Ω
DE
B
B
DI
D
D
DI
DE
RO
RE
A
B
A
B
A
A
R
R
RO
RE
R
MAX3082E
MAX3085E
MAX3088E
MAX3089E (HALF-DUPLEX)
R
D
D
DI
DE
RO RE
DI
DE
RO RE
Figure 22. Typical Half-Duplex RS-485 Network
Driver Output Protection
Typical Applications
Two mechanisms prevent excessive output current and
power dissipation caused by faults or by bus contention. The first, a foldback current limit on the output
stage, provides immediate protection against short circuits over the whole common-mode voltage range (see
Typical Operating Characteristics). The second, a thermal shutdown circuit, forces the driver outputs into a
high-impedance state if the die temperature becomes
excessive.
The MAX3082E/MAX3085E/MAX3088E/MAX3089E
transceivers are designed for bidirectional data communications on multipoint bus transmission lines.
Figures 22 and 23 show typical network applications
circuits. These parts can also be used as line repeaters,
with cable lengths longer than 4000 feet, as shown in
Figure 18.
To minimize reflections, the line should be terminated at
both ends in its characteristic impedance, and stub
lengths off the main line should be kept as short as
possible. The slew-rate-limited MAX3082E/MAX3085E,
and the two modes of the MAX3089E, are more tolerant
of imperfect termination.
Line Length vs. Data Rate
The RS-485/RS-422 standard covers line lengths up to
4000 feet. For line lengths greater than 4000 feet, use
the repeater application shown in Figure 18.
Figures 19, 20, and 21 show the system differential voltage for the parts driving 4000 feet of 26AWG twistedpair wire at 110kHz into 120Ω loads.
______________________________________________________________________________________
19
MAX3080E–MAX3089E
MAX3080/3089 FIG 20
MAX3080/3089 FIG 19
MAX3080E–MAX3089E
±15kV ESD-Protected, Fail-Safe, High-Speed (10Mbps),
Slew-Rate-Limited RS-485/RS-422 Transceivers
A
R
RO
RE
Y
120Ω
120Ω
D
B
Z
Z
B
DE
DI
DI
DE
120Ω
D
Y
120Ω
Z
Y
B
A
Y
Z
B
R
A
RE
RO
A
R
D
D
DI
R
DE RE RO
DI
DE RE RO
NOTE: RE AND DE ON MAX3080E/MAX3083E/MAX3086E/MAX3089E ONLY.
MAX3080E
MAX3081E
MAX3083E
MAX3084E
MAX3086E
MAX3087E
MAX3089E (FULL-DUPLEX)
Figure 23. Typical Full-Duplex RS-485 Network
Ordering Information (continued)
PART
MAX3081ECSA
MAX3081ECPA
MAX3081EESA
MAX3081EEPA
MAX3082ECSA
MAX3082ECPA
MAX3082EESA
MAX3082EEPA
MAX3083ECSD
MAX3083ECPD
MAX3083EESD
MAX3083EEPD
MAX3084ECSA
MAX3084ECPA
MAX3084EESA
MAX3084EEPA
MAX3085ECSA
MAX3085ECPA
MAX3085EESA
MAX3085EEPA
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
14 SO
14 Plastic DIP
14 SO
14 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
PART
MAX3086ECSD
MAX3086ECPD
MAX3086EESD
MAX3086EEPD
MAX3087ECSA
MAX3087ECPA
MAX3087EESA
MAX3087EEPA
MAX3088ECSA
MAX3088ECPA
MAX3088EESA
MAX3088EEPA
MAX3089ECSD
MAX3089ECPD
MAX3089EESD
MAX3089EEPD
TEMP. RANGE
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
14 SO
14 Plastic DIP
14 SO
14 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
8 SO
8 Plastic DIP
14 SO
14 Plastic DIP
14 SO
14 Plastic DIP
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
20
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