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Entry  Fri May 17 18:58:58 2013, Jamie, Koji, Summary, CDS, Weird DAC bit flipping at half integer output values const.pdfsweep.pdf
    Reply  Fri May 17 19:56:52 2013, Koji, Summary, CDS, Weird DAC bit flipping at half integer output values 
    Reply  Wed May 22 11:09:33 2013, Jamie, Summary, CDS, Weird DAC bit flipping at half integer output values nopad.pdf
       Reply  Wed May 22 11:21:28 2013, Koji, Summary, CDS, Weird DAC bit flipping at half integer output values 
          Reply  Wed May 22 11:35:06 2013, Jamie, Summary, CDS, Weird DAC bit flipping at half integer output values 
             Reply  Wed May 22 15:08:37 2013, Koji, Summary, CDS, Weird DAC bit flipping at half integer output values Screenshot.png
Message ID: 8615     Entry time: Wed May 22 11:35:06 2013     In reply to: 8614     Reply to this: 8616
Author: Jamie 
Type: Summary 
Category: CDS 
Subject: Weird DAC bit flipping at half integer output values 

Quote:

Is this limit cycle caused by the residual of the digital AI filtering at the half sampling freq and that his the threshold?
Or is this some nonlinear effect? If this is a linear effect associated with the zero-padding, the absolute
value of the DC may affect the amplitude of the oscillation. (Or equivalently the range of the DC where we get this oscillation.)

This is a good question.  We may be able to test if it's a linear effect if we have enough DAC range to get the oscillation to be more than a single sample.

Quote:

You pointed out the ringdown of the digital AI filter in the sample-hold case (i.e. no-zero-padding case).
How does it look like in the conventional zero-padding case?

 In the zero-pad case the oscillation just continues indefinitely at the half-count value, so it never dies out (at least as far as I can tell).

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