DescriptionThe SP4082E is designed for reliable, bidirectional communication on multipoint bus transmission lines. The device contains one differential driver and one differential receiver. It is a half-duplex de- vice. The device complys with TIA/EIA-485 and TIA/EIA-422 standards. Lead-free and RoHS compli- ant packages are available.
This device is ruggedized for use in harsh operating conditions over the entire common-mode volt- age range from -7V to +2V. Receivers are specially designed to fail-safe to a logic high output state if the inputs are un-driven or shorted. All RS-485 bus-pins are protected against severe ESD events up to ±15kV (Human Body Model). Drivers are protected from excess current flow caused by bus contention or output short-circuits by both an internal current limit and a thermal-overload shutdown. Devices are rated for industrial (-40 to +85oC) operating temperatures. Receivers have exceptionally high input impedance, which places only /8th the standard load on a shared bus. Up to 256 transceivers may coexist while preserving full signal margin.
The device operates from a single 5.0V power supply and draws negligible quiescent power. The device has an independent enable and disable for the driver and receiver and will enter a low power shutdown mode if both driver and receiver are disabled. All outputs maintain high impedance during shutdown or when powered-off.
For technical support or help choosing a product please email Exar’s Serial Technical Support group at: email@example.com.
- 5.0V Single Supply Operation
- Controlled Driver Slew Rates 115kbps, Low EMI
- Receiver Failsafe on Open or Shorted Lines
- 1/8th Unil Load, 256 Transceivers on Bus
- Robust ESD Protection for RS-485 Pins +/-15KV Human Body Model
- Driver Short Circuit Current Limit and Thermal Shutdown for Overload Protection
- Industry Standard Package Footprints
- Motor Control
- Building Automation
- Security Systems
- Remote Meter Reading
Parts & Purchasing
|Part Number||Pkg Code||RoHS||Min Temp||Max Temp||Status||Buy Now||Order Samples|
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.
Frequently Asked Questions
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. When you hover over it, it will turn grey and you can click anywhere in the grey box. This brings you to the product page. For example:
Click on Parts & Purchasing, highlighted in yellow 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:
Another method to find out if a part is OBS or EOL is to click on SUPPORT:
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.