4-Channel E3/DS3/STS-1 Line Iinterface Unit with Jitter Attenuator
Data Sheet


The XRT75L04 is a Four-Channel fully integrated Line Interface Unit (LIU) and Jitter Attenuator for E3/DS3/STS-1 applications. It incorporates four independent Receivers, Transmitters and Jitter Attenuators in a single 176 pin TQFP package.

Each channel of the XRT75L04 can be independently configured to operate in E3 (34.368 MHz), DS3 (44.736 MHz) or STS-1 (51.84 MHz) rates. Each transmitter can be turned off and tri-stated for redundancy support and power conservation. The XRT75L04’s differential receivers provide high noise interference margin and are able to receive the data over 1000 feet of cable, or with cable attenuation of up to 12 dB.

The XRT75L04 incorporates an advanced crystal-less jitter attenuator per channel that can be selected either in the transmit or receive path. The jitter attenuator performance meets the ETSI TBR-24 and Bellcore GR-499 specifications. The XRT75L04 provides both Serial Microprocessor Interface as well as a Hardware mode for programming and control.

The XRT75L04 supports local, remote and digital loop-backs. The XRT75L04 also contains an on-board Pseudo Random Binary Sequence (PRBS) generator and detector with the ability to insert and detect single bit error.


  • On chip Clock and Data Recovery circuit for high input jitter tolerance
  • Meets E3/DS3/STS-1 Jitter Tolerance Requirements
  • Detects and Clears LOS as per G.775
  • Receiver Monitor mode handles up to 20 dB flat loss with 6 dB cable attenuation
  • On chip B3ZS/HDB3 encoder and decoder that can be either enabled or disabled
  • On-chip Clock Synthesizer generates the appropriate rate clock from a single frequency Crystal
  • Provides low jitter clock outputs for either E3, DS3 or STS-1 rates
  • Meets Jitter Tolerance Requirements, as specified in ITU-T G.823_1993 for E3 Applications
  • Meets Jitter Tolerance Requirements, as specified in Bellcore GR-499-CORE for DS3 Applications
  • Compliant with Bellcore GR-499, GR-253 and ANSI T1.102 Specification for transmit pulse
  • Tri-state Transmit output capability for redundancy applications
  • Transmitter can be turned on or off Jitter Attenuator:
  • On chip advanced crystal-less Jitter Attenuator
  • Jitter Attenuators can be selected in Receive or Transmit paths
  • Compliant with jitter transfer template outlined in ITU G.751, G.752, G.755, GR-253 and GR-499-CORE,1995 standards
  • Meets ETSI TBR 24 Jitter Transfer Requirements
  • 16 or 32 bits selectable FIFO size
  • Meets the Jitter and Wander specifications described in ANSI T1.105.03b
  • Jitter Attenuators can be disabled
Control and Diagnostics:
  • 5 wire Serial Microprocessor Interface for control and configuration
  • Supports optional internal Transmit Driver Monitoring
  • PRBS Error Counter Register to accumulate errors
  • Hardware Mode for control and configuration
  • Supports Local, Remote and Digital Loop-backs
  • Single 3.3 V ± 5% power supply
  • 5 V Tolerant I/O
  • Available in 176 pin TQFP
  • -40°C to 85°C Industrial Temperature Range
  • Pb-Free, RoHS Compliant Versions Offered


  • E3/DS3 Access Equipment
  • STS1-SPE to DS3 Mapper
  • DSLAMs
  • Digital Cross Connect Systems
  • CSU/DSU Equipment
  • Routers
  • Fiber Optic Terminals

Design Tools

Simulation Models
Package Type Vcc Temp Mode Version File
QFP 3.3V Industrial 3


Pkg Code Details Quantities Dimensions PDF
  • JEDEC Reference: MO-026
  • MSL Pb-Free: L4 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 32.7ºC/W
  • Bulk Pack Style: Tray
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 750
  • Quantity per Tube: n/a
  • Quantity per Tray: 40
  • Reel Size (Dia. x Width x Pitch): 330 x 44 x 32
  • Tape & Reel Unit Orientation: Pin 1 at sprocket hole.
  • Dimensions: mm
  • Length: 24.00
  • Width: 24.00
  • Thickness: 1.60
  • Lead Pitch: 0.50

Parts & Purchasing

Part Number Pkg Code Min Temp Max Temp Status Buy Now Order Samples
XRT75L04IV LQFP176 OBS Suggested:
XRT75L04IV-F LQFP176 -40 85 Active Order
XRT75L04IVTR LQFP176 OBS Suggested:
XRT75L04IVTR-F LQFP176 -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

Part Number RoHS | Exempt RoHS Halogen Free REACH MSL Rating / Peak Reflow Package
XRT75L04IV-F N Y Y Y L4 / 260ᵒC LQFP176

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
07/11/2017 Product Discontinuation Notification
12/05/2013 Addition of an alternate qualified assembly site, ASE Chung-Li (Taiwan) for assembly using copper or gold wire bonding. Material change and alternate assembly site.
10/03/2013 Product Discontinuation Notification Discontinued.
03/19/2013 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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