|3.3V Low Power Full Duplex RS-485 Transceivers with 10Mbps Data Rate
|Supply Voltage (Nom) (V)
|No. of Tx
|No. of Rx
|Data Rate (MAX) (Mbps)
|HBM ESD (kV)
|IEC 61000-4-2 Contact (±kV)
|Transient Tolerance (V)
|Fault Tolerance (V)
|Temperature Range (°C)
|0 to 70, -40 to 85
|ICC (Max) (mA)
|Typ Shutdown Current (µA)
|PROFIBUS (5V) or High Output (3V)
The SP3490 and SP3491 devices are +3.3V low power full-duplex transceivers that meet the specifications of the RS-485 and RS-422 serial protocols. These devices are pin-to-pin compatible with the MaxLinear SP490 and SP491 devices as well as popular industry standards. The SP3490 and SP3491 feature MaxLinear's BiCMOS process, allowing low power operation without sacrificing performance. The SP3490 and SP3491 meet the electrical specifications of the RS-485 and RS-422 serial protocols up to 10Mbps under load. The SP3491 is identical to the SP3490 with the addition of driver and receiver tri-state enable lines.
- Full Duplex RS-485 and RS-422 Transceivers
- Operates from a single +3.3V supply
- Interoperable with +5.0V logic
- -7V to +12V Common-Mode Input Voltage Range
- +200mV Receiver Input Sensitivity
- Allows up to 32 transceivers on the serial bus
- Compatibility with LTC490 and SN75179
Documentation & Design Tools
|SP3490/SP3491 +3.3V Low Power Full-Duplex RS-485 Transceivers with 10Mbps Data Rate
|AN-291, RS-485 Advanced Fail-Safe Feature
|RS-232 and RS-485 PCB Layout Application Note
|AN-292, RS-485 Cable Lengths vs Data Signaling Rate
|ANI-13, RS-485 and RS-422 Physical Topologies
Quality & RoHS
|RoHS | Exempt
|MSL Rating / Peak Reflow
|L1 / 260ᵒC
|L1 / 260ᵒC
|L1 / 260ᵒC
Click on the links above to download the Certificate of Non-Use of Hazardous Substances.
Parts & Purchasing
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.
FAQs & Support
Search our list of FAQs for answers to common technical questions.
For material content, environmental, quality and reliability questions review the Quality tab or visit our Quality page.
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Submit a Technical Support Question As a New Question
For RS-232 it is 50 feet (15 meters), or the cable length equal to a capacitance of 2500 pF, at a maximum transmission rate of 19.2kbps. When we reduce the baud rate, it allows for longer cable length. For Example:
Baud Rate (bps)
Maximum RS-232 Cable Length (ft)
Fail Safe is an attempt to keep the output of the RS-485 receiver to a known state. Transceivers may have standard fail safe or advanced / enhanced receiver fail safe features. Standard fail safe supports open inputs while enhanced fail safe transceivers such as the SP339 and XR34350 support open input, shorted input and undriven terminated lines without external biasing. See Application Note ANI-22 for more detail.
The Parts & Purchasing section of the product page shows the Status of all orderable part numbers for that product. Click Show obsolete parts, to see all EOL or OBS products.