Description
The XRT8001 is a single-chip, dual phase-locked loop clock adapter for WAN and ISDN applications. This product accommodates the most popular frequencies encountered in T1/E1 access equipment, T1/E1 multiplexers and concentrators, sub-rate switches, routers, Frame Relay Access Devices (FRADs), Remote Access Servers (RASs) and both PRI and BRI ISDN equipment.
Using a serial processor interface the designer can fully control the operational modes of the device by modifying the content of the internal registers. Designed with two internal phase locked loops, the XRT8001 generates two output clocks from a single input reference clock. Each of the two outputs can be independently programmed to generate frequency multiples of 64kHz and 56kHz from T1 and E1 ates.
The extremely impressive jitter performance of the XRT8001 makes it ideal for any equipment deployed in public or private networks with strict regulatory requirements. The device synthesizes two low-jitter clocks with user-selected, industry-standard frequencies, phased-locked to the system reference timing, making it capable of generating less than 0.05UI of wideband.
This chip has several modes of operation to provide designers with greatest flexibility. In the forward master mode, XRT8001 accepts up to 16th harmonic of either 1.544MHz (T1) or 2.048MHz (E1) as input reference, and generates multiples of 56kHz or 64kHz. In the reverse master mode, an input clock of 56kHz or 64kHz is used to generate 1.544MHz (T1) or 2.048MHz (E1) output clocks. In the fractional T1/E1 reverse master mode, the XRT8001 accepts up to the 32nd harmonic of 56kHz or 64kHz as input reference, and generates either 1.544MHz (T1) or 2.048MHz (E1). In the E1 to T1 master mode, the device acccepts up tp the 16th harmonic of 2.048MHz (E1) as input reference and generates 1.544MHz (T1). In the high speed reverse mode, the XRT8001 accepts 64kHz as input reference and generates multiples (1, 2, 4, or 8) of 2.048MHz (E1).
The forward and reverse modes can also be operated in slave configuration where the device generates the same output frequencies as master configuration while being phase locked to an 8kHz input reference.
Features
- Clock adaptation for most popular telecommunication frequencies
- Wide input frequency range
- Programmable output frequencies
- Less than 0.05UI wide band output jitter
- Low power operation (5V and 3.3V)
- Maximum lock time of 45ms
- Pb-Free, RoHS Compliant Versions Offered
Documentation
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Datasheet
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Schematics
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Product Brochure
Application
- DSU/CSU
- Frame Relay Access Devices (FRADs)
- Basic Rate (BRI) and Primary Rate (PRI) ISDN terminals
- Concentrators and multiplexers
Design Tools
Packaging
Parts & Purchasing
| Part Number | Pkg Code | RoHS | Min Temp | Max Temp | Status | Buy Now | Order Samples |
|---|---|---|---|---|---|---|---|
| XRT8000ID-F | WSOIC18 | -40 | 85 | Active | Order | ||
| XRT8000IDTR-F | WSOIC18 | -40 | 85 | OBS |
Suggested: XRT8000ID-F |
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| XRT8000IP-F | OBS |
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
https://www.exar.com/quality-assurance-and-reliability/lead-free-program
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.