Embedded Systems Conference
Home    Bloggers    Blogs    Article Archives    Messages    About Us   
Tw  |  Fb  |  In  |  Rss
Jonathan Harris

ADC Noise: The Clock Input & Phase Noise (Jitter), Part 2

Jonathan Harris
etnapowers
etnapowers
3/11/2014 7:18:48 AM
User Rank
Master
Re: measurement accuracy
@jonharris0: yes, it does make sense to me, the ADC determines the perfomance of the system not only for data sampling but also for data conditioning, the data in binary format are stored in the computer memory, that has to be capable of storing a big quantity of data, depending on the resolution of the ADC.

50%
50%
jonharris0
jonharris0
3/10/2014 7:47:12 AM
User Rank
Blogger
Re: measurement accuracy
Great question.  The data conversion is done inside the ADC so the performance is determined inside the ADC.  The software on the PC is merely processing the digital data that has already been converted by the ADC.  Does this make sense?

50%
50%
etnapowers
etnapowers
3/10/2014 3:50:01 AM
User Rank
Master
Re: measurement accuracy
@jonharris0: I'm looking forward for a blog on this. you're welcome, thank you for the details you provided, I guess that the data are collected in the memory of the PC by a conditioning system to convert the data from analog to digital format.

50%
50%
jonharris0
jonharris0
3/5/2014 4:35:53 PM
User Rank
Blogger
Re: measurement accuracy
This is a good point to look at.  Actually, the instrumentation that makes the most difference in terms of testing the ADC in this manner is the analog input signal generator for the ADC and the reference input signal generator for the clocking IC.  The measurements are done on a PC using Visual Analog software.  Perhaps a good topic for a blog would be an overview of the test setup to show how this data was collected on the AD9643 and AD9523. Thanks for the question!

50%
50%
etnapowers
etnapowers
3/5/2014 11:11:23 AM
User Rank
Master
measurement accuracy
The correlation between simulated and measured results is good, provided that there is a good accuracy of the testing instrumentation utilized in laboratory to test the noise.

50%
50%
jonharris0
jonharris0
3/3/2014 9:04:51 AM
User Rank
Blogger
Re: Jitter equation
Hi DaeJ, thanks for your comments!  Great question! The equations can be applied to any ADC and clocking source, not just the AD9643 and AD9523.  These two devices are just given for an example to show that the math will predict the overall SNR. 

100%
0%
DaeJ
DaeJ
3/2/2014 3:25:09 PM
User Rank
Master
Jitter equation
It is validated that the predicted data was almost the same as that of measurement data. These equations are based on AD9643 and AD9523 with clock input to calculate jitter noise. I wonder whether these equations could be applied to other components made by different manufacture.

50%
50%
More Blogs from Jonathan Harris
Before looking into the signal chain portion of the tool we began by looking at the calculator tool available in ADIsimRF.
The topic of this blog came up while at the IMS show and one of my colleagues mentioned that I should discuss the ADIsimRF tool as a part of the series. I thought this was a marvelous idea. Iíll have to precursor this discussion with the fact that I am actually an RF guy from my previous employment at an RF company which was my first position when I graduated from college.
One of the questions that appeared on one of the IMS blog posts was about the details of the demonstration I had set up at the Analog Devices booth.
The last and final day of the show is usually has the most relaxed atmosphere and this year that proved to be the case once again. It is the shortest day of the show lasting from just 9:00 AM to 3:00 PM.
After having a pretty good first day of the show, I was looking forward to a good second day and it did not disappoint. The second day of the show on Wednesday is the longest day of the show as the exhibit hours go from 9:00 AM until 6:00 PM (day one is 9:00 AM to 5:00 PM and day three is 9:00 AM to 3:00 PM).
flash poll
educational resources
 
follow Planet Analog on Twitter
Planet Analog Twitter Feed
like us on facebook
our partners
Planet Analog
About Us     Contact Us     Help     Register     Twitter     Facebook     RSS