Filtering VDAC noise

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Anonymous
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I downloaded DMA DAC training code from the site. Direct output from the VDAC contains "switching" noise of the DAC. A simple low-pass filter is added to remove the noise.

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Anonymous
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Filtered DAC output

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Anonymous
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Panson thanks for sharing this with the rest of the community. 

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Anonymous
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Hi,

   

Thanks for sharing!

   

The noise you got was 80KHz?

   

I am getting ~ 50Hz according to the oscilloscope

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ETRO_SSN583
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If you are getting power line noise your grounds to scope not right. The principle

   

noise seen in the Vdacout is relatively high (to 50 Hz) switching noise coupled

   

on chip and external by stray C.

   

 

   

Depending on what you are doing you may have to float scope ground. See attached.

   

 

   

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CEgQFjAAahUKEwjeqMSShYDHAhUK04A...

   

 

   

Regards, Dana.

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ETRO_SSN583
Level 9
Level 9
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Take a look at this discussion on power line interference -

   

 

   

http://electronics.stackexchange.com/questions/78920/my-scope-detects-a-50hz-signal-when-the-probe-i...

   

 

   

Regards, Dana.

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