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loop bandwidth and ppm tolerance? (Read 4577 times)

supermoment Senior Member Offline Posts: 167	loop bandwidth and ppm tolerance? May 12^th, 2011, 6:14am For the 1st order PI CDR, if it can tolerate until 500ppm of freq1. Does it mean the loop bandwidth is around (500ppm/1e6)*freq1? Is the loop bandwidth different to the ppm tolerance?
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rfidea Senior Member Offline Posts: 159 Europe	Re: loop bandwidth and ppm tolerance? Reply #1 - May 12^th, 2011, 8:47am What is a PI CDR?
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supermoment Senior Member Offline Posts: 167	Re: loop bandwidth and ppm tolerance? Reply #2 - May 13^th, 2011, 5:28pm PI = phase interpolator CDR= clock and data recovery circuit
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loose-electron Senior Fellow Offline Best Design Tool = Capable Designers Posts: 1638 San Diego California	Re: loop bandwidth and ppm tolerance? Reply #3 - May 16^th, 2011, 5:40pm if you want an answer here I think you need to define the question a lot more
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raja.cedt

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Re: loop bandwidth and ppm tolerance?
Reply #4 - May 19^th, 2011, 12:03pm

loop BW: How fast it can track Phase and frequency variations.

PPM(specific to CDR): How much frequency difference that can be tracked by CDR between data and clock with out loosing lock.

For a first order CDR there is no PPM (for most of the cases), i guess you are intended to ask 2nd order CDR

PI based CDR means Phase interpolation based Clock and Data Recovery

Thanks.

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newic Senior Member Offline Posts: 138	Re: loop bandwidth and ppm tolerance? Reply #5 - May 20^th, 2011, 6:12pm I think the first order PI based CDR can tolerance some PPM, depending on filter setting. For the loop BW, it is mainly determined by main loop parameter, excluding the 2nd order loop.
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