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Jonathan Harris

Interleaving Spurs: Offset Mismatches

Jonathan Harris
jonharris0
jonharris0
7/15/2013 9:10:59 AM
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Blogger
Re: Calibration / DC components
@DaeJ, thanks for the question.  The figure is intended just to show that the offset mismatch exists.  It is not necessarily a calibration circuit, sorry for the confusion on that.

@B_Albing, thanks for the comment as well...that is something good to keep in mind.  I'm hoping to dive into a few more of the mismatches in upcoming blogs, but perhaps a good direction afterward may be to discuss some calibration methods...

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B_Albing
B_Albing
7/15/2013 12:17:57 AM
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Editor
Re: Calibration / DC components
@JH - more details on auto-cal methods to remove (or match) DC offset in a future blog, perhaps....

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DaeJ
DaeJ
7/14/2013 5:35:02 PM
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Master
Two ADADC71 chips
I think that in most case, A/D converter chip is used to get A/D from VIN in the circuit. For example, let us say that two ADADC71 chips, 16 bit A/D converter, are used in parallel similar to "Offset mismatch" figure above. I am wondering how this circuit overcomes offset mismatch in this case.

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jonharris0
jonharris0
7/12/2013 3:50:07 PM
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Blogger
Re: Calibration / DC components
Hi Dirceu, yes, a calibration procedure would definitely help.  When doing the calibration you'd need to make sure not to remove the DC content as many applications use content around DC.  As I mentioned, one approach would be to just make the offset of each ADC equal so you don't affect the incoming DC content of the input signal.

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DirceuRodriguesJr
DirceuRodriguesJr
7/12/2013 12:58:45 PM
User Rank
Artist
Calibration / DC components
Jonathan,

  With ADC offset mismatches, a calibration procedures could help? Perhaps some kind of DC restore circuit (op. amp. or software based). I think in measuring devices, for example in the medical field: Unlike the ECG, an oximeter need the DC components of the signal.

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