digitally controlled potentiometer

[estradasphere]

hi,

is there a rough formula to calculate the accuracy of digitally controlled potentiometers? i want to estimate the accuracy of a DCP which compensates the dc-offset at the input of an op-amp. since the offset voltage in my circuit frequently changes, the dc-offset is cancelled by the DCP. does a DCP have a lower accuracy for low offset voltages? if yes, a certain dc-offset at the input of the op-amp still remains. all i want is to estimate the the error of the DCP for different input dc-offset voltages to calculate the remaining dc-offset.

thanks

 

[IanP]

I don't think there is a formula to calculate accuracy of a digital potentiometer ..
You will have to refer to a particular potentiometer's data sheet ..
Here is an example:
"APPLICATION NOTE 629
Digitally Adjustable Voltage References"
**broken link removed**

Regards,
IanP

 

[yousafzai]

It does not seem to be controlled through a formula. U can calculate the precision/ resolution of a Dig Pot by simply dividing the total resistance with the number of digital steps. U can find excellent Dig Pots from Xicor.

 

[surajit]

Hi All,

Can we have more discussion on DCP or any help to know more about DCP.

Thanks