MAX490:Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers

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.

Key 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
MAX1487, MAX481, MAX483, MAX485, MAX487, MAX488, MAX489, MAX490, MAX491: Pin Configuration and Typical Operating Circuit
MAX1487, MAX481, MAX483, MAX485, MAX487, MAX488, MAX489, MAX490, MAX491: Pin Configuration and Typical Operating Circuit
Applications/Uses
  • Industrial-Control Local Area Networks
  • Level Translators
  • Low-Power RS-422 Transceivers
  • Low-Power RS-485 Transceivers
  • Transceivers for EMI-Sensitive Applications
DataSheet
titleDownload file
MAX1487-MAX491 Data SheetMAX1487-MAX491.pdf
Parametrics
Part NumberTx/RxDuplexVSUPPLY
(V)
ICC
(mA)
Data Rate
(kbps)
Tx ENRx ENICC (Shutdn.)
(µA)
Rx/Tx on BusRx Failsafe w/ InputsSlew Rate LimitingOper. Temp.
(°C)
Package/PinsBudgetary
Price
typmintypSee Notes
MAX14871Tx + 1RxHalf50.32500YesYes-128OpenNo-55 to +125
-40 to +85
0 to +70
µMAX/8
PDIP(N)/8
SOIC(N)/8
$1.54 @1k
MAX481Half0.52500YesYes0.132µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
MAX483Half0.35250YesYes0.132µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
MAX485Half0.52500YesYes-32µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
MAX487Half0.25250YesYes0.1128µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
MAX488Full0.12250NoNo-32µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
MAX489Full0.12250YesYes-32CDIP(N)/14
PDIP(N)/14
SOIC(N)/14
MAX490Full0.32500NoNo-32µMAX/8
CDIP(N)/8
PDIP(N)/8
SOIC(N)/8
MAX491Full0.32500YesYes-32CDIP(N)/14
PDIP(N)/14
SOIC(N)/14
Quality and Environmental Data
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX490C/DNo Longer AvailableDICE;0°C to +70°CSee data sheet
MAX490CPANo Longer AvailableMAX490CPA+PDIP(N),;8 pin;79.7 mm²0°C to +70°CNo
MAX490CPA+ActivePDIP(N),;8 pin;79.7 mm²0°C to +70°CLead Free
MAX490CSANo Longer AvailableMAX490CSA+SOIC(N),;8 pin;30.9 mm²0°C to +70°CNo
MAX490CSA+ActiveSOIC(N),;8 pin;30.9 mm²0°C to +70°CLead Free
MAX490CSA+TActiveSOIC(N),;8 pin;30.9 mm²0°C to +70°CLead Free
MAX490CSA-TNo Longer AvailableMAX490CSA+TN.SO;8 pin0°C to +70°CSee data sheet
MAX490CUANo Longer AvailableMAX490CUA+µMAX,;8 pin;15.6 mm²0°C to +70°CNo
MAX490CUA+ActiveµMAX,;8 pin;15.6 mm²0°C to +70°CLead Free
MAX490CUA+TActiveµMAX,;8 pin;15.6 mm²0°C to +70°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX490CUA-TNo Longer AvailableMAX490CUA+TµMAX,;8 pin;15.6 mm²0°C to +70°CNo
MAX490EPANo Longer AvailableMAX490EPA+PDIP(N),;8 pin;79.7 mm²-40°C to +85°CNo
MAX490EPA+ActivePDIP(N),;8 pin;79.7 mm²-40°C to +85°CLead Free
MAX490ESANo Longer AvailableMAX490ESA+SOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
MAX490ESA+ActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
MAX490ESA+TActiveSOIC(N),;8 pin;30.9 mm²-40°C to +85°CLead Free
MAX490ESA-TNo Longer AvailableMAX490ESA+TSOIC(N),;8 pin;30.9 mm²-40°C to +85°CNo
MAX490MJAActiveCDIP(N),;8 pin;82.6 mm²-55°C to +125°CNo
MAX490MJA/883BActiveCDIP(N),;8 pin;82.6 mm²-55°C to +125°CNo
MAX1487-MAX491.pdf MAX491
MAX1487-MAX491_cn.pdf MAX491
MAX490.pdf MAX490
MAX1487-MAX491_cn.pdf MAX491