For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
General Description
The MAX481, MAX483, MAX485, MAX487MAX491, and
MAX1487 are low-power transceivers for RS-485 and RS-
422 communication. Each part contains one driver and one
receiver. The MAX483, MAX487, MAX488, and MAX489
feature reduced slew-rate drivers that minimize EMI and
reduce reflections caused by improperly terminated cables,
thus allowing error-free data transmission up to 250kbps.
The driver slew rates of the MAX481, MAX485, MAX490,
MAX491, and MAX1487 are not limited, allowing them to
transmit up to 2.5Mbps.
These transceivers draw between 120µA and 500µA of
supply current when unloaded or fully loaded with disabled
drivers. Additionally, the MAX481, MAX483, and MAX487
have a low-current shutdown mode in which they consume
only 0.1µA. All parts operate from a single 5V supply.
Drivers are short-circuit current limited and are protected
against excessive power dissipation by thermal shutdown
circuitry that places the driver outputs into a high-imped-
ance state. The receiver input has a fail-safe feature that
guarantees a logic-high output if the input is open circuit.
The MAX487 and MAX1487 feature quarter-unit-load
receiver input impedance, allowing up to 128 MAX487/
MAX1487 transceivers on the bus. Full-duplex communi-
cations are obtained using the MAX488MAX491, while
the MAX481, MAX483, MAX485, MAX487, and MAX1487
are designed for half-duplex applications.
________________________Applications
Low-Power RS-485 Transceivers
Low-Power RS-422 Transceivers
Level Translators
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
__Next Generation Device Features
For Fault-Tolerant Applications
MAX3430: ±80V Fault-Protected, Fail-Safe, 1/4
Unit Load, +3.3V, RS-485 Transceiver
MAX3440EMAX3444E: ±15kV ESD-Protected,
±60V Fault-Protected, 10Mbps, Fail-Safe,
RS-485/J1708 Transceivers
For Space-Constrained Applications
MAX3460MAX3464: +5V, Fail-Safe, 20Mbps,
Profibus RS-485/RS-422 Transceivers
MAX3362: +3.3V, High-Speed, RS-485/RS-422
Transceiver in a SOT23 Package
MAX3280EMAX3284E: ±15kV ESD-Protected,
52Mbps, +3V to +5.5V, SOT23, RS-485/RS-422,
True Fail-Safe Receivers
MAX3293/MAX3294/MAX3295: 20Mbps, +3.3V,
SOT23, RS-855/RS-422 Transmitters
For Multiple Transceiver Applications
MAX3030EMAX3033E: ±15kV ESD-Protected,
+3.3V, Quad RS-422 Transmitters
For Fail-Safe Applications
MAX3080MAX3089: Fail-Safe, High-Speed
(10Mbps), Slew-Rate-Limited RS-485/RS-422
Transceivers
For Low-Voltage Applications
MAX3483E/MAX3485E/MAX3486E/MAX3488E/
MAX3490E/MAX3491E: +3.3V Powered, ±15kV
ESD-Protected, 12Mbps, Slew-Rate-Limited,
True RS-485/RS-422 Transceivers
MAX481/MAX483/MAX485/MAX487MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
________________________________________________________________ Maxim Integrated Products
1
______________________________________________________________Selection Table
19-0122; Rev 8; 10/03
MAX481
MAX483
MAX485
MAX487
MAX488
MAX489
MAX490
MAX491
MAX1487
PART
NUMBER
HALF/FULL
DUPLEX
DATA RATE
(Mbps)
SLEW-RATE
LIMITED
LOW-POWER
SHUTDOWN
RECEIVER/
DRIVER
ENABLE
QUIESCENT
CURRENT
(
µ
A)
NUMBER OF
TRANSMITTERS
ON BUS
PIN
COUNT
Half
Half
Half
Half
Full
Full
Full
Full
Half
2.5
0.25
2.5
0.25
0.25
0.25
2.5
2.5
2.5
No
Yes
No
Yes
Yes
Yes
No
No
No
Yes
Yes
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
300
120
300
120
120
120
300
300
230
32
32
32
128
32
32
32
32
128
8
8
8
8
8
14
8
14
8
Ordering Information appears at end of data sheet.
MAX481/MAX483/MAX485/MAX487MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
CC
) .............................................................12V
Control Input Voltage (
RE, DE)...................-0.5V to (V
CC
+ 0.5V)
Driver Input Voltage (DI).............................-0.5V to (V
CC
+ 0.5V)
Driver Output Voltage (A, B)...................................-8V to +12.5V
Receiver Input Voltage (A, B).................................-8V to +12.5V
Receiver Output Voltage (RO).....................-0.5V to (V
CC
+0.5V)
Continuous Power Dissipation (T
A
= +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ....727mW
14-Pin Plastic DIP (derate 10.00mW/°C above +70°C) ..800mW
8-Pin SO (derate 5.88mW/°C above +70°C).................471mW
14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW
8-Pin µMAX (derate 4.1mW/°C above +70°C) ..............830mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C).........640mW
14-Pin CERDIP (derate 9.09mW/°C above +70°C).......727mW
Operating Temperature Ranges
MAX4_ _C_ _/MAX1487C_ A ...............................0°C to +70°C
MAX4_ _E_ _/MAX1487E_ A .............................-40°C to +85°C
MAX4_ _MJ_/MAX1487MJA ...........................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
DC ELECTRICAL CHARACTERISTICS
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
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.
V
V
IN
= -7V
V
IN
= 12V
V
IN
= -7V
V
IN
= 12V
Input Current
(A, B)
I
IN2
V
TH
k
48
-7V V
CM
12V, MAX487/MAX1487
R
IN
Receiver Input Resistance
-7V V
CM
12V, all devices except
MAX487/MAX1487
R = 27 (RS-485), Figure 4
0.4V V
O
2.4V
R = 50 (RS-422)
I
O
= 4mA, V
ID
= -200mV
I
O
= -4mA, V
ID
= 200mV
V
CM
= 0V
-7V V
CM
12V
DE, DI, RE
DE, DI, RE
MAX487/MAX1487,
DE = 0V, V
CC
= 0V or 5.25V
DE, DI, RE
R = 27 or 50, Figure 4
R = 27 or 50, Figure 4
R = 27 or 50, Figure 4
DE = 0V;
V
CC
= 0V or 5.25V,
all devices except
MAX487/MAX1487
CONDITIONS
k
12
µA
±1
I
OZR
Three-State (high impedance)
Output Current at Receiver
V
0.4
V
OL
Receiver Output Low Voltage
3.5
V
OH
Receiver Output High Voltage
mV
70
V
TH
Receiver Input Hysteresis
V
-0.2
0.2
Receiver Differential Threshold
Voltage
-0.2
mA
0.25
mA
-0.8
1.0
1.5
5
V
OD2
Differential Driver Output
(with load)
V
2
V
5
V
OD1
Differential Driver Output (no load)
µA
±2
I
IN1
Input Current
V
0.8
V
IL
Input Low Voltage
V
2.0
V
IH
Input High Voltage
V
0.2
V
OD
Change in Magnitude of Driver
Common-Mode Output Voltage
for Complementary Output States
V
0.2
V
OD
Change in Magnitude of Driver
Differential Output Voltage for
Complementary Output States
V
3
V
OC
Driver Common-Mode Output
Voltage
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
MAX481/MAX483/MAX485/MAX487MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
_______________________________________________________________________________________
3
SWITCHING CHARACTERISTICS--MAX481/MAX485, MAX490/MAX491, MAX1487
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
DC ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
mA
7
95
0V V
O
V
CC
I
OSR
Receiver Short-Circuit Current
mA
35
250
-7V V
O
12V (Note 4)
I
OSD2
Driver Short-Circuit Current,
V
O
= Low
mA
35
250
-7V V
O
12V (Note 4)
I
OSD1
Driver Short-Circuit Current,
V
O
= High
MAX1487,
RE = 0V or V
CC
250
400
350
650
ns
10
30
60
t
PHL
Driver Rise or Fall Time
Figures 6 and 8, R
DIFF
= 54, C
L1
= C
L2
= 100pF
ns
MAX490M, MAX491M
MAX490C/E, MAX491C/E
20
90
150
MAX481, MAX485, MAX1487
MAX490M, MAX491M
MAX490C/E, MAX491C/E
MAX481, MAX485, MAX1487
Figures 6 and 8, R
DIFF
= 54,
C
L1
= C
L2
= 100pF
MAX481 (Note 5)
Figures 5 and 11, C
RL
= 15pF, S2 closed
Figures 5 and 11, C
RL
= 15pF, S1 closed
Figures 5 and 11, C
RL
= 15pF, S2 closed
Figures 5 and 11, C
RL
= 15pF, S1 closed
Figures 6 and 10, R
DIFF
= 54,
C
L1
= C
L2
= 100pF
Figures 6 and 8,
R
DIFF
= 54,
C
L1
= C
L2
= 100pF
Figures 6 and 10,
R
DIFF
= 54,
C
L1
= C
L2
= 100pF
CONDITIONS
ns
5
10
t
SKEW
ns
50
200
600
t
SHDN
Time to Shutdown
Mbps
2.5
f
MAX
Maximum Data Rate
ns
20
50
t
HZ
Receiver Disable Time from High
ns
10
30
60
t
PLH
20
50
t
LZ
Receiver Disable Time from Low
ns
20
50
t
ZH
Driver Input to Output
Receiver Enable to Output High
ns
20
50
t
ZL
Receiver Enable to Output Low
20
90
200
ns
ns
13
40
70
t
HZ
t
SKD
Driver Disable Time from High
|
t
PLH
- t
PHL
|
Differential
Receiver Skew
ns
40
70
t
LZ
Driver Disable Time from Low
ns
40
70
t
ZL
Driver Enable to Output Low
3
15
40
ns
5
15
25
ns
3
15
40
t
R
, t
F
20
90
200
Driver Output Skew to Output
t
PLH
, t
PHL
Receiver Input to Output
40
70
t
ZH
Driver Enable to Output High
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
CONDITIONS
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
230
400
300
500
MAX481/MAX485,
RE = 0V or V
CC
500
900
MAX490/MAX491,
DE, DI, RE = 0V or V
CC
300
500
MAX488/MAX489,
DE, DI, RE = 0V or V
CC
120
250
DE = V
CC
300
500
DE = 0V
DE = V
CC
DE = 0V
µA
MAX481/483/487, DE = 0V, RE = V
CC
0.1
10
I
SHDN
Supply Current in Shutdown
120
250
I
CC
No-Load Supply Current
(Note 3)
DE = 5V
DE = 0V
MAX483
MAX487
MAX483/MAX487,
RE = 0V or V
CC
Figures 7 and 9, C
L
= 100pF, S2 closed
Figures 7 and 9, C
L
= 100pF, S1 closed
Figures 7 and 9, C
L
= 15pF, S1 closed
Figures 7 and 9, C
L
= 15pF, S2 closed
µA
MAX481/MAX483/MAX485/MAX487MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
4
_______________________________________________________________________________________
SWITCHING CHARACTERISTICS--MAX483, MAX487/MAX488/MAX489
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
SWITCHING CHARACTERISTICS--MAX481/MAX485, MAX490/MAX491, MAX1487 (continued)
(V
CC
= 5V ±5%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Notes 1, 2)
300
1000
Figures 7 and 9, C
L
= 100pF, S2 closed
Figures 7 and 9, C
L
= 100pF, S1 closed
Figures 5 and 11, C
L
= 15pF, S2 closed,
A - B = 2V
CONDITIONS
ns
40
100
t
ZH(SHDN)
Driver Enable from Shutdown to
Output High (MAX481)
ns
Figures 5 and 11, C
L
= 15pF, S1 closed,
B - A = 2V
t
ZL(SHDN)
Receiver Enable from Shutdown
to Output Low (MAX481)
ns
40
100
t
ZL(SHDN)
Driver Enable from Shutdown to
Output Low (MAX481)
ns
300
1000
t
ZH(SHDN)
Receiver Enable from Shutdown
to Output High (MAX481)
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
t
PLH
t
SKEW
Figures 6 and 8, R
DIFF
= 54,
C
L1
= C
L2
= 100pF
t
PHL
Figures 6 and 8, R
DIFF
= 54,
C
L1
= C
L2
= 100pF
Driver Input to Output
Driver Output Skew to Output
ns
100
800
ns
ns
2000
MAX483/MAX487, Figures 7 and 9,
C
L
= 100pF, S2 closed
t
ZH(SHDN)
Driver Enable from Shutdown to
Output High
250
2000
ns
2500
MAX483/MAX487, Figures 5 and 11,
C
L
= 15pF, S1 closed
t
ZL(SHDN)
Receiver Enable from Shutdown
to Output Low
ns
2500
MAX483/MAX487, Figures 5 and 11,
C
L
= 15pF, S2 closed
t
ZH(SHDN)
Receiver Enable from Shutdown
to Output High
ns
2000
MAX483/MAX487, Figures 7 and 9,
C
L
= 100pF, S1 closed
t
ZL(SHDN)
Driver Enable from Shutdown to
Output Low
ns
50
200
600
MAX483/MAX487 (Note 5)
t
SHDN
Time to Shutdown
t
PHL
t
PLH
, t
PHL
< 50% of data period
Figures 5 and 11, C
RL
= 15pF, S2 closed
Figures 5 and 11, C
RL
= 15pF, S1 closed
Figures 5 and 11, C
RL
= 15pF, S2 closed
Figures 5 and 11, C
RL
= 15pF, S1 closed
Figures 7 and 9, C
L
= 15pF, S2 closed
Figures 6 and 10, R
DIFF
= 54,
C
L1
= C
L2
= 100pF
Figures 7 and 9, C
L
= 15pF, S1 closed
Figures 7 and 9, C
L
= 100pF, S1 closed
Figures 7 and 9, C
L
= 100pF, S2 closed
CONDITIONS
kbps
250
f
MAX
250
800
2000
Maximum Data Rate
ns
20
50
t
HZ
Receiver Disable Time from High
ns
250
800
2000
20
50
t
LZ
Receiver Disable Time from Low
ns
20
50
t
ZH
Receiver Enable to Output High
ns
20
50
t
ZL
Receiver Enable to Output Low
ns
ns
100
300
3000
t
HZ
t
SKD
Driver Disable Time from High
I
t
PLH
- t
PHL
I
Differential
Receiver Skew
Figures 6 and 10, R
DIFF
= 54,
C
L1
= C
L2
= 100pF
ns
300
3000
t
LZ
Driver Disable Time from Low
ns
250
2000
t
ZL
Driver Enable to Output Low
ns
Figures 6 and 8, R
DIFF
= 54,
C
L1
= C
L2
= 100pF
ns
250
2000
t
R
, t
F
250
2000
Driver Rise or Fall Time
ns
t
PLH
Receiver Input to Output
250
2000
t
ZH
Driver Enable to Output High
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
MAX481/MAX483/MAX485/MAX487MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
_______________________________________________________________________________________
5
30
0
0
2.5
OUTPUT CURRENT vs.
RECEIVER OUTPUT LOW VOLTAGE
5
25
MAX481-01
OUTPUT LOW VOLTAGE (V)
OUTPUT CURRENT (mA)
1.5
15
10
0.5
1.0
2.0
20
35
40
45
0.9
0.1
-50
-25
25
75
RECEIVER OUTPUT LOW VOLTAGE vs.
TEMPERATURE
0.3
0.7
TEMPERATURE (°C)
OUTPUT LOW VOLTAGE (V)
0
50
0.5
0.8
0.2
0.6
0.4
0
100
125
MAX481-04
I
RO
= 8mA
-20
-4
1.5
2.0
3.0
5.0
OUTPUT CURRENT vs.
RECEIVER OUTPUT HIGH VOLTAGE
-8
-16
MAX481-02
OUTPUT HIGH VOLTAGE (V)
OUTPUT CURRENT (mA)
2.5
4.0
-12
-18
-6
-14
-10
-2
0
3.5
4.5
4.8
3.2
-50
-25
25
75
RECEIVER OUTPUT HIGH VOLTAGE vs.
TEMPERATURE
3.6
4.4
TEMPERATURE (°C)
OUTPUT HIGH VOLTAGE (V)
0
50
4.0
4.6
3.4
4.2
3.8
3.0
100
125
MAX481-03
I
RO
= 8mA
90
0
0
1.0
3.0
4.5
DRIVER OUTPUT CURRENT vs.
DIFFERENTIAL OUTPUT VOLTAGE
10
70
MAX481-05
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
2.0
4.0
50
30
80
60
40
20
0.5
1.5
2.5
3.5
2.3
1.5
-50
-25
25
125
DRIVER DIFFERENTIAL OUTPUT VOLTAGE
vs. TEMPERATURE
1.7
2.1
MAX481-06
TEMPERATURE (
°
C)
DIFFERENTIAL OUTPUT VOLTAGE (V)
0
75
1.9
2.2
1.6
2.0
1.8
100
50
2.4
R = 54
__________________________________________Typical Operating Characteristics
(V
CC
= 5V, T
A
= +25°C, unless otherwise noted.)
NOTES FOR ELECTRICAL/SWITCHING CHARACTERISTICS
Note 1:
All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device
ground unless otherwise specified.
Note 2:
All typical specifications are given for V
CC
= 5V and T
A
= +25°C.
Note 3:
Supply current specification is valid for loaded transmitters when DE = 0V.
Note 4:
Applies to peak current. See
Typical Operating Characteristics.
Note 5:
The MAX481/MAX483/MAX487 are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less
than 50ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 600ns, the parts are
guaranteed to have entered shutdown. See Low-Power Shutdown Mode section.
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