|Information||3.3V Low Power Full Duplex RS-485 Transceivers with 10Mbps Data Rate|
|Supported Protocols||RS-422, RS-485|
|Supply Voltage (Nom) (V)||3.3|
|No. of Tx||1|
|No. of Rx||1|
|HBM ESD (kV)||2|
|IEC 61000-4-2 Contact (±kV)||-|
|Temperature Range (°C)||0 to 70, -40 to 85|
|Data Rate (MAX) (Mbps)||10|
|ICC (Max) (mA)||2|
|Typ Shutdown Current (µA)||10|
|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
- Driver/Receiver Tri-state Enable Lines
- -7V to +12V Common-Mode Input Voltage Range
- +200mV Receiver Input Sensitivity
- Allows up to 32 transceivers on the serial bus
- Compatibility with LTC491 and SN75180
Documentation & Design Tools
|Data Sheets||SP3490/SP3491 +3.3V Low Power Full-Duplex RS-485 Transceivers with 10Mbps Data Rate||1.0.3||September 2017||481.9 KB|
|Application Notes||AN-292, RS-485 Cable Lengths vs Data Signaling Rate||R00||May 2022||2.7 MB|
|Application Notes||AN-291, RS-485 Advanced Fail-Safe Feature||00||January 2022||920.5 KB|
|Application Notes||ANI-13, RS-485 and RS-422 Physical Topologies||D||December 2006||183.2 KB|
|Product FAQs||SP3491 FAQ||1.0.0||October 2006||179.8 KB|
|Product Brochures||Interface Brochure||October 2019||1.3 MB|
Quality & RoHS
|Part Number||RoHS | Exempt||RoHS||Halogen Free||REACH||TSCA||MSL Rating / Peak Reflow||Package|
|SP3491CN-L||N||Y||Y||Y||Y||L2 / 260ᵒC||NSOIC14|
|SP3491CN-L/TR||N||Y||Y||Y||Y||L2 / 260ᵒC||NSOIC14|
|SP3491EN-L||N||Y||Y||Y||Y||L2 / 260ᵒC||NSOIC14|
|SP3491EN-L/TR||N||Y||Y||Y||Y||L2 / 260ᵒC||NSOIC14|
Click on the links above to download the Certificate of Non-Use of Hazardous Substances.
Parts & Purchasing
|Part Number||Pkg Code||Min Temp||Max Temp||Status||Suggested Replacement||Buy Now||Order Samples||PDN|
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.
For ordering information and general customer service visit our Contact Us page.
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.
In this example, we looked for XRA1201. Click on part number header or on the link at the bottom of the result. This brings you to the product page. For example:
Click on Parts & Purchasing, highlighted with the blue arrow above. The screen changes to:
Notice the status column and the “Show obsolete parts” link. A legend tells you the definition of the different statuses. Click on the “Show obsolete parts” link to see EOL or OBS part numbers along with the Active part numbers, the legend still present:
Another method to find out if a part is OBS or EOL is to click on SUPPORT at the top:
And then Product Change Notifications:
Type the part into the search, and click on one of the part numbers from the drop down menu. Then you can look for the Product Discontinuation Notice, which generally is at the top of the list, for example:
If you see this, it tells you that this particular orderable part has been discontinued and when the last order date is, or was. If you click on the file, then you can view the notice we sent about this if you purchased the part in the recent past. It may also advise of a replacement part. When an orderable part first becomes discontinued, Product Discontinuation Notices are sent are sent to those who have purchased the parts in the recent past, if purchased directly, with a dated opportunity to place a last order.