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
Functional Diagrams
Level Translators
__Next Generation Device Features
♦ 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
♦ 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
♦ For Multiple Transceiver Applications
MAX3030E–MAX3033E: ±15kV ESD-Protected,
+3.3V, Quad RS-422 Transmitters
♦ For Fail-Safe Applications
MAX3080–MAX3089: 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
Transceivers for EMI-Sensitive Applications
Industrial-Control Local Area Networks
Ordering Information appears at end of data sheet.
______________________________________________________________Selection Table
DATA
RATE
(Mbps)
SLEW-RATE
LIMITED
LOWRECEIVER/ QUIESCENT
POWER
DRIVER
CURRENT
SHUTDOWN
ENABLE
(μA)
NUMBER OF
RECEIVERS ON
BUS
PIN
COUNT
300
32
8
120
32
8
300
32
8
Yes
120
128
8
No
120
32
8
Yes
120
32
14
No
No
300
32
8
No
Yes
300
32
14
No
Yes
230
128
8
PART
NUMBER
HALF/FULL
DUPLEX
MAX481
Half
2.5
No
Yes
Yes
MAX483
Half
0.25
Yes
Yes
Yes
MAX485
Half
2.5
No
No
Yes
MAX487
Half
0.25
Yes
Yes
MAX488
Full
0.25
Yes
No
MAX489
Full
0.25
Yes
No
2.5
No
PinMAX490
Configurations Full
appear at end of data sheet.
Functional Diagrams continued at end of dataNo
sheet.
MAX491
Full
2.5
UCSP is a trademark of Maxim Integrated Products, Inc.
MAX1487
Half
2.5
No
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-0122; Rev 9; 9/09
