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 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-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
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 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-855/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
ABSOLUTE MAXIMUM RATINGS
Supply Voltage
(VCC).............................................................12V
Control Input Voltage (RE, DE)...................-0.5V to (VCC +
0.5V)
Driver Input Voltage (DI).............................-0.5V to (VCC
+ 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 (VCC
+0.5V)
Continuous Power Dissipation (TA = +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
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.
Figure 1. MAX481/MAX483/MAX485/MAX487/MAX1487 Pin Configuration and
Typical Operating Circuit
Figure 2. MAX488/MAX490 Pin Configuration and Typical Operating
Circuit
Figure 3. MAX489/MAX491 Pin Configuration and Typical Operating
Circuit
