The XR3070-78X family of high performance RS-485/422 devices are designed for improved performance in noisy industrial environments and increased tolerance to system faults.
The analog bus pins can withstand direct shorts up to ±18V, and are protected against ESD events up to ±15kV. The differential high output driver delivers 10% higher SNR than standard RS-485/422 devices, affording additional noise margin or extended cable lengths.
The receivers include full fail-safe circuitry, guaranteeing a logic-high receiver output when the receiver inputs are open, shorted, or undriven. The receiver input impedance is at minimum 96kΩ (1/8 unit load), allowing up to 256 devices on the bus while preserving the full signal margin.
The drivers are protected by short circuit detection as well as thermal shutdown, and maintain high impedance in shutdown or when powered off. The XR3070-75X drivers are slew limited for reduced EMI and error-free communication over long or unterminated data cables.
The devices with DE and RE pins include hot swap circuitry to prevent false transitions on the bus during powerup or live insertion, and can enter a 1nA low current shutdown mode for extreme power savings.
The transceivers draw less than 600µA from a +3.3V supply, and typically only 300µA when idling with the receivers active.
For technical support or help choosing a product please email Exar’s Serial Technical Support group at: firstname.lastname@example.org.
- 10% Higher SNR (Signal-to-Noise Ratio) compared to other RS-485 devices (1.65V vs. 1.5V)
- ±18V Fault Tolerance on Analog Bus pins
- Robust ESD (ElectroStatic Discharge) Protection:
- ±15kV IEC 61000-4-2 Air Gap Discharge
- ±8kV IEC 61000-4-2 Contact Discharge
- ±15kV Human Body Model
- ±4kV Human Body Model on non-bus pins
- +3.0V to +3.6V Operation (3.3V ± 10%)
- 300µA Idle Current, 1nA Shutdown Current
- Enhanced Receiver Fail-Safe Protection for Open, Shorted, or Terminated but Idle Data Lines
- Hot-Swap Glitch Protection on DE and RE Pins
- Driver Short Circuit Current Limit and Thermal Shutdown for Overload Protection
- 1/8th Unit Load Allows up to 256 Devices on Bus
- Industry Standard 8 and 14 NSOIC Packages
- Motor Control
- Security Systems
- Building and Process Automation
- Remote Utility Meter Reading
- Energy Monitoring and Control
- Long or Unterminated Transmission Lines
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.