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3224 dynamic range/oversampling

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3224 dynamic range/oversampling

Postby Audioguy » Sat Feb 17, 2007 7:50 am

Hi!

Questions in an endless stream from this newbie scope user. :)

There's a document on the Pico website stating that the effective resolution of the 12bit 3224 can be increased to 16bit on some signals by using oversampling.

How is that possible?

I thought that the analog to digital chip had a fixed 12bit resolution and it would seem to me that is the absolut limit for how low a signal that can be seen on the tinput of the chip.

Or is it so, that the actual ADC has more than 12bit but are limited by overall noise in the scope circuits, and by averaging the noise can be supressed and hence a higher effecdtive resolution?

Please help me to shed some light on thios issue.

/Peter
Audioguy
 

Postby alan » Mon Feb 26, 2007 6:51 pm

Hi,

The following post from the regular email newsletter probably answers this better than I can!

http://www.picotech.com/newsletter/news ... e06.html#1

Regards
Alan
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Postby Guest » Tue Feb 27, 2007 8:12 am

Thanks Alan!

Unfortunately I still don't get it.. :?

I did read the info in the newsletter but I still don't understand how the resolution can be increased to 16bit from a 12bit analog to digital converter.

I realize that noise can be supressed by averaging several blocks of samples of a static or sine like signal. However I thought that only noise injected from the outside world and the powesupplys could be surpressed.

After all the last bit of the ADC should set the limit on how low a voltage can be sensed on the input.

I would really appreciate some enlighting info on the subject, as the newsletter seems not to answer my questions really.

Thanks and best regards!

/Peter
Guest
 

Postby alan » Tue Feb 27, 2007 8:39 am

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Postby Audioguy » Sat Mar 03, 2007 9:51 am

Thanks for the pointers Alan.

Still haven't found what I'm looking for.. but I'll keep on searching!

:)

/Peter
Audioguy
 


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