XR3078X

Low Power 18V Tolerant RS-485/RS-422 +3.3V Transceivers
Data Sheets Active
Order Now

Overview

Information Low Power 18V Tolerant RS-485/RS-422 +3.3V Transceivers
Supported Protocols RS-422, RS-485
Supply Voltage (Nom) (V) 3.3
No. of Tx 1
No. of Rx 1
Duplex Half
Data Rate (MAX) (Mbps) 20
HBM ESD (kV) 15
IEC 61000-4-2 Contact (±kV) 8
Rx Fail-Safe Advanced
Multi-Drop Nodes 256
Transient Tolerance (V) -70 to 70
Fault Tolerance (V) -18 to 18
VL Pin
Temperature Range (°C) -40 to 85
Package NSOIC-8
ICC (Max) (mA) 0.6
Shutdown ✔
Typ Shutdown Current (µA) 1nA
Hot Swap ✔
PROFIBUS (5V) or High Output (3V) ✔
Show more

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 15% 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.


  • 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

Documentation & Design Tools

All Types Data Sheets Application Notes Product Briefs & Brochures
Type Title Version Date File Size
Data Sheets XR3070-78X Low Power 18V Tolerant RS-485/RS-422 +3.3V Transceivers 1.0.3 October 2019 230.2 KB
Application Notes RS-485 Transceivers in Fieldbus Networks R00 October 2024 2.4 MB
Application Notes DAN-190, MaxLinear UARTs in RS-485 Applications R01 July 2023 2.4 MB
Application Notes AN-291, RS-485 Advanced Fail-Safe Feature R01 May 2023 3.7 MB
Application Notes RS-232 and RS-485 PCB Layout Application Note R00 December 2022 2.8 MB
Application Notes AN-292, RS-485 Cable Lengths vs Data Signaling Rate R01 July 2022 2.7 MB
Product Brochures Interface Brochure R02 November 2024 3.6 MB
Register for a myMxL account or Login to myMxL to view all Technical Documentation & Design Tools.

Quality & RoHS

Part Number RoHS | Exempt RoHS Halogen Free REACH TSCA MSL Rating / Peak Reflow Package
XR3078XIDTR-F N Y Y Y Y L1 / 260ᵒC NSOIC8
XR3078XID-F N Y Y Y Y L1 / 260ᵒC NSOIC8

Click on the links above to download the Certificate of Non-Use of Hazardous Substances.

Additional Quality Documentation may be available, please Contact Support.

Parts & Purchasing

Part Number Pkg Code Min Temp Max Temp Status Buy Now Order Samples
XR3078XID-F NSOIC8 -40 85 Active Order
XR3078XIDTR-F NSOIC8 -40 85 Active Order

Part Status Legend
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.

Packaging

Pkg Code Details Quantities Dimensions
NSOIC8
  • JEDEC Reference: MS-012
  • MSL Pb-Free: L1 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 128.4ºC/W (std); 96.8ºC/W (fused)
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: 98
  • Quantity per Reel: 2500
  • Quantity per Tube: 98
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 330 x 12 x 8
  • Tape & Reel Unit Orientation: Quadrant 1
  • Dimensions: mm
  • Length: 4.90
  • Width: 3.90
  • Thickness: 1.75
  • Lead Pitch: 1.27

Notifications

Distribution Date Description File
07/17/2023 In 2023, MaxLinear will be converting all shipping labels for the parts noted from an EXAR format to MaxLinear’s label. During this transition customers may receive either label. This change affects only shipping and packing labels. This change will not affect the part number, part marking, manufacturing process or manufacturing sites. Only work in progress material will be converted. Existing inventory from MaxLinear’s warehouse, channel sales, distributor, and such, will not be converted. Hence, customers may experience receiving mixed shipments with both Exar and MaxLinear labels for some period until existing inventory of old labels is eventually cleared out. Situation is product to product with no predictable way to determine when all old labels will be exhausted. No change to product form, fit, function and reliability. ADDENDUM A: Fixed MBB label logo for DX204001 to MaxLinear logo. ADDENDUM B: Replaced ‘All other affected products outer box label’ with clearer pictures. Corrected Date Issued (from original PCN) issue date +90 days to August 30, 2023.
06/01/2023 In 2023, MaxLinear will be converting all shipping labels for the parts noted from an EXAR format to MaxLinear’s label. During this transition customers may receive either label. This change affects only shipping and packing labels. This change will not affect the part number, part marking, manufacturing process or manufacturing sites. Only work in progress material will be converted. Existing inventory from MaxLinear’s warehouse, channel sales, distributor, and such, will not be converted. Hence, customers may experience receiving mixed shipments with both Exar and MaxLinear labels for some period until existing inventory of old labels is eventually cleared out. Situation is product to product with no predictable way to determine when all old labels will be exhausted. No change to product form, fit, function and reliability.
06/01/2023 In 2023, MaxLinear will be converting all shipping labels for the parts noted from an EXAR format to MaxLinear’s label. During this transition customers may receive either label. This change affects only shipping and packing labels. This change will not affect the part number, part marking, manufacturing process or manufacturing sites. Only work in progress material will be converted. Existing inventory from MaxLinear’s warehouse, channel sales, distributor, and such, will not be converted. Hence, customers may experience receiving mixed shipments with both Exar and MaxLinear labels for some period until existing inventory of old labels is eventually cleared out. Situation is product to product with no predictable way to determine when all old labels will be exhausted. No change to product form, fit, function and reliability. ADDENDUM: Fixed MBB label logo for DX204001 to MaxLinear logo.
07/11/2017 Product Discontinuation Notification
02/15/2017 Qualification of alternate assembly subcon, ANST.
04/28/2016 Qualification of alternate assembly subcon, JCET.

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)

19200

50

9600

500

4800

1000

2400

3000
 
For RS-485 / RS-422 the data rate can exceed 10Mbps depending on the cable length. A cable length of 15 meters (50 feet) will do a maximum of 10Mbps. A cable length of 1200 meters (4000 feet) will do a maximum of 90kbps over 24 AWG gauge twisted pair cable (with 10 pF/ft). Refer to Annex A TIA/EIA-422-B. Also refer the RS-485 Cable Lengths vs. Data Signaling Rate Application Note (AN-292).
 
 

As RS-422/RS-485 uses differential signaling, it is more immune to noise and longer cables and/or high data rates can be used, especially in noisy environments. Also, RS-485 allows for multi-point operation, up to 32 unit loads. Transceivers may use a fraction of a unit load, increasing the number of devices on the bus. For example, the XR33152 receiver input impedance is at least 120 kΩ, which equates to 1/10 of a unit load. Therefore, XR33152 allows more than 320 devices (32 x 10) on the bus.

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.

 

Figure 1:  Standard Failsafe Receiver Sensitivity Range
 


 

 
Figure 2: Standard Failsafe with Open Input
 
 
 
Figure 3: Enhanced Failsafe Receiver Sensitivity Range
 
 
 
Figure 4:  Enhanced Failsafe with Open Input
 
 
 
Figure 5:  Enhanced Failsafe with Shorted Input
 
 
 
Figure 6:  Enhanced Failsafe with Un-driven terminated lines
 
 
 

Yes, this is possible using one RS-485 transceiver. The microcontrollers will have to be addressable and have tri-state outputs. The RS-485 device can be controlled by the host via the DE/RE pin. The micros will have to be in either receiving mode or tri-state mode when the RS-485 transceiver is transmitting data. When the host transmits it will have to send an address to the specific micro. If any micro transmits the transceiver will have to be in receiving mode and all other micros will have to be in receive or tri-state. So the host would have to initiate this sequence by addressing the micro first then switch the transceiver to receive.
The half duplex system would have a bus with one transceiver and multiple microcontrollers all tied to the bus. For 5V systems the SP485 family can be used. For 3V systems the SP3070 family can be used. The require speed will determine the part number. The SP3078 part runs up to speeds of 16Mbps.  See the parametric search on https://www.exar.com/products/interface/serial-transceivers/rs485-422 for more options.
Care must be taken to assure the transceiver can drive the multiple micros in RX mode.

ESD tests are “destructive tests.” The part is tested until it suffers damage. Therefore parts cannot be 100% tested in production, instead a sample of parts are characterized during the product qualification. The test procedure consists of “zapping” pins with a given voltage using the appropriate model and then running the part through electrical tests to check for functionality or performance degradation.

ESD is caused by static electricity. In order for an ESD event to occur there must be a buildup of static charge. Very high charge levels are actually quite rare. In a normal factory environment, taking basic ESD precautions (grounding-straps, anti-static smocks, ionizers, humidity control, etc.) static levels can be kept below a few tens of volts. In an uncontrolled environment, like an office, static levels rarely get above 2000 volts. Under some worstcase conditions (wearing synthetic fabrics, rubbing against synthetic upholstered furniture, extremely low humidity)
levels can go as high as 12 to 15 thousand volts. Actually to get to 15000 volts or higher you would need to be in an uncomfortably dry environment (humidity below 10%) otherwise static charge will naturally dissipate through corona discharge. It would definitely be considered a “bad hair day.” Humans can generally feel a static shock only above 3000 volts. A discharge greater than 4000 volts can cause an audible “pop.” But repeated lower level discharges can be imperceptible and still may have a cumulative damaging effect on sensitive ICs. All ICs, even those with robust protection, can be damaged if they are hit hard enough or often enough.

Most ICs in a typical system are at greatest risk of ESD damage in the factory when the PCB is assembled and the system is being built. After the system is put together they are soldered onto the PCB and shielded within a metal or plastic system enclosure. Interface ICs are designed to attach to an external connector that could be exposed to ESD when a cable is plugged in or when a person or object touches the connector. These interface pins are most likely to see ESD exposure and therefore benefit from additional protection.

Actually the letter “E” could have two different meanings, depending on where it is in the part number. Most of our interface devices are available in different temperature grades. Commercial temperature (0 to 70C) has a “C” after the numeric part number. Industrial-extended temperature (-40 to +85C) use the letter E. So for example SP485CN is commercial and SP485EN is industrial. The second letter indicates the package type, in this case N for narrow-SOIC. Another E in the suffix indicates that this device has enhanced ESD protection, typically of ±15000Volts on the interface pins. Devices that do not have the enhanced ESD still contain built-in ESD protection of at least ±2000Volts. For example the SP485ECN is ESD rated up to ±15kV, and the SP485CN is rated for ±2kV HBM.

The -F suffix indicates ROHS / Green compliance:
https://www.exar.com/quality-assurance-and-reliability/lead-free-program

Visit the product page for the part you are interested in.  The part's status is listed in the Parts & Purchasing section.  You can also view Product Lifecycle and Obsolescence Information including PDNs (Product Discontinuation Notifications).
 
To visit a product page, type the part into the search window on the top of the MaxLinear website.
 
In this example, we searched for XRA1201.  Visit the product page by clicking the part number or visit the orderable parts list by clicking "Orderable Parts". 
 
 
 

 

  

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.

 
 
 

 

Videos

English Chinese

RS-485 Transceivers - Advance vs. Standard Failsafe

MaxLinear offers RS-485 transceivers with both standard and advanced receiver failsafe features. This video will show the main differences and advantages between advanced failsafe receivers and standard failsafe receivers in a typical RS485 installation.

Tips to Maintain a Successful RS-485 Link

This video provides four tips to help maintain RS-485 serial communication without data loss

Company
Information
Contact Us
Careers
Maximize Your Potential

Join the MaxLinear team and help shape the future of networking and communications technology.

© 2024 MaxLinear. All Rights Reserved.