MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
General Description
The MAX481, MAX483, MAX485, MAX487–MAX491, and
MAX1487 are low-power transceivers for RS-485 and RS422 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-impedance 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 communications are obtained using the MAX488–MAX491, 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
__Next Generation Device Features
o For Fault-Tolerant Applications
MAX3430: ±80V Fault-Protected, Fail-Safe, 1/4
Unit Load, +3.3V, RS-485 Transceiver
MAX3440E–MAX3444E: ±15kV ESD-Protected,
±60V Fault-Protected, 10Mbps, Fail-Safe,
RS-485/J1708 Transceivers
o For Space-Constrained Applications
MAX3460–MAX3464: +5V, Fail-Safe, 20Mbps,
Profibus RS-485/RS-422 Transceivers
MAX3362: +3.3V, High-Speed, RS-485/RS-422
Transceiver in a SOT23 Package
MAX3280E–MAX3284E: ±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-485/RS-422 Transmitters
o For Multiple Transceiver Applications
MAX3030E–MAX3033E: ±15kV ESD-Protected,
+3.3V, Quad RS-422 Transmitters
o For Fail-Safe Applications
MAX3080–MAX3089: Fail-Safe, High-Speed
(10Mbps), Slew-Rate-Limited RS-485/RS-422
Transceivers
o 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
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Ordering Information appears at end of data sheet.
______________________________________________________________Selection Table
DATA
RATE
(Mbps)
LOWRECEIVER/ QUIESCENT
POWER
DRIVER
CURRENT
SHUTDOWN
ENABLE
(μA)
NUMBER OF
RECEIVERS ON
BUS
PART
NUMBER
HALF/FULL
DUPLEX
MAX481
Half
2.5
No
Yes
Yes
300
32
8
MAX483
Half
0.25
Yes
Yes
Yes
120
32
8
MAX485
Half
2.5
No
No
Yes
300
32
8
MAX487
Half
0.25
Yes
Yes
Yes
120
128
8
MAX488
Full
0.25
Yes
No
No
120
32
8
MAX489
Full
0.25
Yes
No
Yes
120
32
14
MAX490
Full
2.5
No
No
No
300
32
8
MAX491
Full
2.5
No
No
Yes
300
32
14
MAX1487
Half
2.5
No
No
Yes
230
128
8
SLEW-RATE
LIMITED
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
PIN
COUNT
19-0122; Rev 10; 9/14
MAX481/MAX483/MAX485/
MAX487–MAX491/MAX1487
Low-Power, Slew-Rate-Limited
RS-485/RS-422 Transceivers
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2)
PARAMETER
SYMBOL
TYP
MAX
MAX488/MAX489,
DE, DI, RE = 0V or VCC
CONDITIONS
MIN
120
250
MAX490/MAX491,
DE, DI, RE = 0V or VCC
300
UNITS
500
ICC
MAX481/MAX485,
RE = 0V or VCC
DE = VCC
500
900
DE = 0V
300
500
MAX1487,
RE = 0V or VCC
No-Load Supply Current
(Note 3)
DE = VCC
300
500
DE = 0V
230
400
MAX483
350
650
MAX487
250
120
0.1
400
250
10
µA
MAX483/MAX487,
RE = 0V or VCC
DE = 5V
µA
Supply Current in Shutdown
ISHDN
DE = 0V
MAX481/483/487, DE = 0V, RE = VCC
Driver Short-Circuit Current,
VO = High
IOSD1
-7V ≤ VO ≤12V (Note 4)
35
250
mA
Driver Short-Circuit Current,
VO = Low
IOSD2
-7V ≤ VO ≤12V (Note 4)
35
250
mA
Receiver Short-Circuit Current
IOSR
0V ≤ VO ≤ VCC
7
95
mA
MAX
60
60
10
40
25
40
70
70
70
70
200
150
200
UNITS
SWITCHING CHARACTERISTICS—MAX481/MAX485, MAX490/MAX491, MAX1487
(VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2)
PARAMETER
Driver Input to Output
Driver Output Skew to Output
Driver Rise or Fall Time
Driver Enable to Output High
Driver Enable to Output Low
Driver Disable Time from Low
Driver Disable Time from High
Receiver Input to Output
| tPLH - tPHL | Differential
Receiver Skew
Receiver Enable to Output Low
Receiver Enable to Output High
Receiver Disable Time from Low
Receiver Disable Time from High
Maximum Data Rate
Time to Shutdown
Maxim Integrated
SYMBOL
CONDITIONS
tPLH
Figures 6 and 8, RDIFF = 54Ω,
CL1 = CL2 = 100pF
tPHL
tSKEW
Figures 6 and 8, RDIFF = 54Ω, CL1 = CL2 = 100pF
MIN
10
10
MAX481, MAX485, MAX1487
Figures 6 and 8,
tR, tF
RDIFF = 54Ω,
MAX490C/E, MAX491C/E
CL1 = CL2 = 100pF MAX490M, MAX491M
tZH
Figures 7 and 9, CL = 100pF, S2 closed
tZL
Figures 7 and 9, CL = 100pF, S1 closed
tLZ
Figures 7 and 9, CL = 15pF, S1 closed
tHZ
Figures 7 and 9, CL = 15pF, S2 closed
Figures 6 and 10, MAX481, MAX485, MAX1487
MAX490C/E, MAX491C/E
tPLH, tPHL RDIFF = 54Ω,
CL1 = CL2 = 100pF MAX490M, MAX491M
3
5
3
20
20
20
TYP
30
30
5
15
15
15
40
40
40
40
90
90
90
tSKD
Figures 6 and 10, RDIFF = 54Ω,
CL1 = CL2 = 100pF
13
tZL
tZH
tLZ
tHZ
Figures 5 and 11, CRL = 15pF, S1 closed
Figures 5 and 11, CRL = 15pF, S2 closed
Figures 5 and 11, CRL = 15pF, S1 closed
Figures 5 and 11, CRL = 15pF, S2 closed
20
20
20
20
50
50
50
50
200
600
fMAX
tSHDN
MAX481 (Note 5)
2.5
50
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Mbps
ns
3
