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Honored Contributor I
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How to find the precision/accuracy of system clock on Cyclone III starter board

Hi, 

 

I'm a student who has just begun to use FPGAs. How can I find the precision and accuracy of the 50 MHz system clock of the Cyclone III Starter Board? I've looked at the User Guide and at other web documentation but I haven't been able to find this particular information.  

 

Thank you so much if you can respond.
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Honored Contributor I
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There should be a bill of materials somewhere in the documentation for the board. Find the manufacturer's part# for the 50MHz oscillator and then find a data sheet for that part. The data sheet will give you the information you need.

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Honored Contributor I
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--- Quote Start ---  

 

I'm a student who has just begun to use FPGAs. How can I find the precision and accuracy of the 50 MHz system clock of the Cyclone III Starter Board? 

 

--- Quote End ---  

 

Perhaps a more important question is, "Why are you interested in that parameter?"  

 

Most cheap oscillators will have specifications like 50MHz with some parts-per-million (ppm) tolerance ... Mouser has a pull-down menu with the PPM tolerance .... 

 

http://www.mouser.com/passive-components/frequency-control-timing-devices/oscillators/standard-clock... 

 

If you really had a "precision" application, then the on-board oscillator might not be what you should use? For example, you might be better off connecting your board to an externa clock source that is generated by a synthesizer. 

 

Describe your concern or interest, and people can chime in with advice. 

 

Cheers, 

Dave
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Honored Contributor I
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Thank you both! 

 

Using the BOM linked to on this page: http://www.linear.com/solutions/5129 

 

I found this: http://www.digikey.com/product-detail/en/ecs-inc/ecs-3953c-500-tr/xc726ct-nd/274086 

 

 

 

Frequency Stability = ±100ppm 

 

 

 

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