Hi ,

I am working on the calculation of DC performance for the ADCs .

In analog devices sigma Delta ADC datasheets, Integral Non Linearity (INL) is given in the unit of

**ppm of FSR**whereas in SAR ADC datasheets INL is specified in the unit of**ppm**.How do i calculate the total error due to INL for a particular ADC and compare it for those ADCs?

Is the above calculation is correct ?

*For Example,*

*I have taken 5 volts as reference voltage of ADC for calculation.*

*If the INL is 3 ppm , I have taken total error due to INL as 15uV (=3uV*5)*

*If the INL is 3 ppm of FSR, I have taken total error due to INL as 3uV (as it is given in ppm of FSR)*

Thanks & Regards,

Rajesh K

Hi Rajesh K,

The ppm is sometimes used in ADC parameters like as you mentioned in INL. The ppm is usually referred to full scale or max input voltage. The ppm and ppm of FSR should be the same. When ppm is the unit, it assume that it is refer to the full scale voltage.

There are ADCs that have fixed voltage range, and there are also that have variable voltage range. the ppm of FSR can be applicable on this type of ADCs.

Regards,

Jonathan