VDAC Output at Zero

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Anonymous
Not applicable

Can someone explain why the VDAC output is not zero volts when it is set to zero?

   

 

   

My test showed a voltage of 1.4mV when I set the VDAC to zero. Is this simply a voltage offset orginating from a buffer used in the component? I'm not sure of the exact design of the VDAC, but I do know that it is based on the IDAC.

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Anonymous
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 VDAC offset can be a maximum of 1LSb. This is 4mV in 1V mode and 16mV in 4V mode. In additon, if you are using an Op-Amp to buffer VDAC output, the Op-amp offset(max 1.5mV) will be an addition contribution

   

Regards,

   

Praveen

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ETRO_SSN583
Level 9
Level 9
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1.4 mV is equivalent to 1.4 mA thru 1 ohm. So other factors can be board

   

layout (trace resistance), split grounds, and where you took your ground

   

reference, a number of factors, in addition to VDAC specs.

   

 

   

Some additional info that may be of help, attached. AN280 in particular.

   

 

   

Regards, Dana.

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