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K22F DAC glitches when crossing midpoint

Question asked by SCOTT MILLER on Mar 5, 2018
Latest reply on Mar 6, 2018 by SCOTT MILLER

I'm using the MK22FN1M0AVLH12's 12-bit DAC for audio output and I'm seeing a consistent glitch in the DAC's output.  Every time the signal crosses the midpoint of the DAC's range I get a brief (~0.7 us) excursion of about +60 mV.

 

I've got it sending samples via DMA, and the DAC's buffer is enabled.  To rule out a problem in my reconstruction filter I've removed it completely; I'm just measuring straight from the DAC.  I set it up to do a slow ramp across the full range and the problem is consistent.

 

0.7 us is consistent with the code-to-code settling time given in the datasheet but I'm surprised by the amplitude of the glitch.  Is there a way to reduce this?

 

Thanks,

 

Scott

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