|Information||Advanced Failsafe RS-485/RS-422 Transceivers 1/8th Unit Load, Slew-Rate Limited, ±15kV ESD-Protected|
|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)||8|
|Temperature Range (°C)||-40 to 85|
|Data Rate (MAX) (Mbps)||0.5|
|ICC (Max) (mA)||0.9|
|Typ Shutdown Current (µA)||1|
|PROFIBUS (5V) or High Output (3V)|
The SP3080E-SP3088E family of RS-485 devices are designed for reliable,
bidirectional communication on multipoint bus transmission lines. Each
device contains one differential driver and one differential receiver.
The SP3082E, SP3085E and SP3088E are half-duplex devices; other part
numbers are full-duplex. All devices comply with TIA/EIA-485 and
TIA/EIA-422 standards. Lead-free and RoHS compliant packages are
available for all models.
These devices are ruggedized for use in harsh operating conditions over the entire common-mode voltage range from -7V to +12V. Receivers are specially designed to fail-safe to a logic high output state if the inputs are left un-driven or shorted. All RS-485 bus-pins are protected against severe ESD events up to ±15kV (Air-Gap and Human Body Model) and up to ±8kV Contact Discharge (IEC 1000- 4-2). 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 1/8th the standard load on a shared bus. Up to 256 transceivers may coexist while preserving full signal margin.
All devices operate from a single 5.0V power supply and draw negligible quiescent power. All versions except the SP3081E, SP3084E, and SP3087E may independently enable and disable their driver and receiver and enter a low power shutdown mode if both driver and receiver are disabled. All outputs maintain high impedance in shutdown or when powered-off.
- Half Duplex RS485 Transceiver
- 5.0V Single Supply Operation
- Slew rate controlled driver, Low EMI
- 500kbps data rate
- Receiver failsafe on open, short or terminated lines
- 1/8th Unit Load, 256 transceivers on bus
- Hot Swap glitch protection on control inputs
- Driver short circuit current limit and thermal shutdown for overload protection
- Ultra-low 400μA Quiescent Current
- 1μA shutdown mode
- Industry standard package footprints
- Robust ESD Specifications:
- ±15KV Human Body Model
- ±8KV IEC1000-4-2 Contact Discharge
Documentation & Design Tools
|Data Sheets||SP308xE Advanced-Failsafe RS-485 / RS-422 Transceivers||2.0.0||July 2022||480.5 KB|
|Application Notes||DAN-190, MaxLinear UARTs in RS-485 Applications||2||December 2022||2.3 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|
|Application Notes||AN-291, RS-485 Advanced Fail-Safe Feature||00||January 2022||920.5 KB|
|Application Notes||AN-214, RS-485 Transient vs. Fault Protection||October 2011||142.2 KB|
|Application Notes||ANI-13, RS-485 and RS-422 Physical Topologies||D||December 2006||183.2 KB|
|Application Notes||ANI-20, Advanced Features of the SP3070E-SP3078E and SP3080E- SP3088E High Performance RS-485 Transceivers||K||October 2006||615.7 KB|
|Product Brochures||Interface Brochure||October 2022||3.8 MB|
Quality & RoHS
|Part Number||RoHS | Exempt||RoHS||Halogen Free||REACH||TSCA||MSL Rating / Peak Reflow||Package|
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||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.
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.
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.
No, the maximum fault tolerance of the above devices is ±18V only. However, the XR3305x and XR3315x families DO support up to ±60V fault tolerance. To find the device in the XR3305x and XR3315x families with the configuration you are looking for, use the parametric search https://www.exar.com/products/interface/serial-transceivers/rs485-422. The Fault Tolerance column is on the right side of the table. See the filters on the left for device selection. See Application Note ANI-23 https://www.exar.com/ani-23.pdf for more on fault testing of these devices.
For any voltage above ±60V, refer to diode manufacturers, such as the Bourns RS-485 transient protection for example below, for an external diode to absorb the transient or surge voltage for protection.or