Calculation of DNL and INL for a R/2R DAC

[Gopal Adhikari]

Hi teachers out there,

I have designed a 4-Bit DAC whose Output is as shown in the attached simulated.txt.
I need to calculate the INL and DNL of the DAC. It also has some gain error.
I tried calculating the dNL and INL. But I think something Fishy is going on with my calculations.
Please help me calculate INL and DNL of this DAC.
i consulted many books and i found some texts but could not verify my calculations.

the picture file contains the calculations done in excel. sorry this forum doesnot support excel file so, i have shown some calculations in the text file.

Please help. what am i doing wrong. how to calculate these parameters with gain and offset errors.

thanks in advance.
Gopal

 

[MikeMl]

Are your tests consistent with the definitions in this app note?

 

[Gopal Adhikari]

Are your tests consistent with the definitions in this app note?

Dear Mike,

I have gone through this app note already.The problem is that my DAC has some gain errors, I don't know how to nullify this error.
this note suggests that INL can be measured after the other errors are nullified

if you have some example workout, it would have been a lot help.

thanks for the reply.

gopal