|Information||Enhanced Full Duplex RS-485 Transceivers|
|Supported Protocols||RS-422, RS-485|
|Supply Voltage (Nom) (V)||5|
|No. of Tx||1|
|No. of Rx||1|
|HBM ESD (kV)||15|
|IEC 61000-4-2 Contact (±kV)||-|
|Temperature Range (°C)||0 to 70, -40 to 85|
|Data Rate (MAX) (Mbps)||10|
|ICC (Max) (mA)||-|
|Typ Shutdown Current (µA)|
|PROFIBUS (5V) or High Output (3V)|
The SP490E is a low power differential line driver/receiver meeting
RS-485 and RS-422 standards up to 10Mbps. The SP491E is identical to the
SP490E with the addition of driver and receiver tri-state enable lines.
Both products feature ±200mV receiver input sensitivity, over wide
common mode range. The SP490E is available in 8-pin plastic DIP and
8-pin NSOIC packages for operation over the commercial and industrial
temperature ranges. The SP491E is available in 14-pin DIP and 14-pin
NSOIC packages for operation over the commercial and industrial
- +5V Only
- Low Power BiCMOS
- Driver/Receiver Enable
- RS-485 and RS-422 Drivers/Receivers
- Pin Compatible with LTC491 and SN75180
- Improved ESD Specifications:
- ±15kV Human Body Model
- ±15kV IEC1000-4-2 Air Discharge
Documentation & Design Tools
|Data Sheets||SP490E_SP491E Enhanced Full Duplex RS-485 Transceivers||1.0.2||March 2018||669.7 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 Brochures||Interface Brochure||October 2019||1.3 MB|
Quality & RoHS
|Part Number||RoHS | Exempt||RoHS||Halogen Free||REACH||TSCA||MSL Rating / Peak Reflow||Package|
|SP491ECN-L/TR||N||Y||Y||Y||Y||L2 / 260ᵒC||NSOIC14|
|SP491EEN-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.