Single Channel E1 Line Interface Unit with JA & CDR


Long established in the E1 arena, Exar proves again, it has the right combination of design expertise, and market knowledge to bring innovative products to market. The XRT82D20 (single-channel), and the XRT81L27 (seven-channel) join several other E1 AFEs and LIUs to give designers a multitude of architecture combinations to meet, or exceed their OEM market requirements.

These new E1 devices, coupled with an already extensive product line including two seven-channel AFEs (XRT5897 and XRT5997), several four-channel devices (XRT5894, XRT5793, XRT5794 and XRT82L24), plus two single-channel parts (XRT59L91 and XRT7288) give EXAR a distinct marketplace advantage. These new products, along with Exar's other E1 LIUs and AFEs give customers a clear, and rich product family spanning DS1/E1 to SONET/SDH. Applications for these new devices include multiplexers (PDH and SDH), digital cross connects, DECT (Digital European Cordless Telephone) base stations, and CSU/DSU equipment.

The seven-channel (XRT81L27), and single-channel device (XRT82D20) complement Exar's already strong E1 The XRT81L27 contains seven independent E1 channels, including data and clock recovery circuits. Each channel performs the driver and receiver functions necessary to convert bipolar signals to logical levels as well as the reverse. Devices with seven E1 interfaces provide the most efficient method of implementing 21-channel line cards.

The device offers two distinct modes of Loss of Signal (LOS) detection: 1) The first approach does not require an external clock, but provides an LOS output indication signal that complies with ITU G.775 requirements; 2) the other approach does invoke an external clock that increases delay of LOS declaration and clearing. This allows the designer to implement LOS specifications that require a greater delay than the G.775 standard.

The XRT82D20 single-channel line interface device supports 75 ohm and 120 ohm E1 applications. It consists of a receiver with adaptive data slicer for accurate data and clock recovery, and a transmitter which accepts either single, or dual-rail digital input for signal line transmission using a low-impedance differential line driver. The XRT82D20 also includes a crystal-less jitter attenuator for clock and data smoothing which can be selected in either the transmit or receive path. The device is a complete line interface unit that allows the physical layer of the system to be implemented without additional components.


  • Seven (or one) independent E1 (CEPT) line interface units (transmitter and receiver) one chip
  • Generates transmit output pulses that are compliant with the ITU-T G.703 pulse template for 2.048Mbps (E1) rates
  • On-chip pulse shaping
  • Compliant with ITU-T G. 838 jitter tolerance requirements
  • Declares and clears Loss of Signal (LOS) meeting ITU-G.775 standards
  • Ultra low power dissipation
  • Low power 3.3V operation
  • Functions over industrial temperature range
  • Pb-Free, RoHS Compliant Versions Offered


Contact Sales to request additional information.


  • PDH multiplexers
  • SDH multiplexers
  • Digital cross-connect systems
  • DECT (Digital European Cordless Telephone) base stations
  • CSU/DSU equipment

Design Tools



Pkg Code Details Quantities Dimensions PDF
  • JEDEC Reference: MO-088
  • MSL Pb-Free: L1 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 46ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 1000
  • Quantity per Tube: 25
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 330 x 24 x 12
  • Tape & Reel Unit Orientation: Pin 1 at sprocket hole.
  • Dimensions: inch
  • Length: 0.705
  • Width: 0.296
  • Thickness: 0.13
  • Lead Pitch: 1.27

Parts & Purchasing

Part Number Pkg Code Min Temp Max Temp Status Buy Now Order Samples
XRT82D20IW SOJ28 -40 85 OBS Suggested:
XRT82D20IW-F SOJ28 -40 85 OBS Suggested:
XRT82D20IWTR SOJ28 -40 85 OBS Suggested:
XRT82D20IWTR-F SOJ28 -40 85 OBS Suggested:
Show obsolete parts
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.

Quality & Environmental Data

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

Additional Quality Documentation may be available, please Contact Support.
Distribution Date Description File
02/01/2019 Product Discontinuation Notice
11/22/2013 Qualification of an alternate qualified 28L SOJ production site, Greatek, Taiwan. Alternate assembly site.
10/03/2013 Product Discontinuation Notification Discontinued.


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.

Frequently Asked Questions

The -F suffix indicates ROHS / Green compliance:

The best way to determine this is to go to maxlinear.com and type the part into the search function. At or near the top of the results you should see something that looks like:

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.

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