In Ad8403A10 datasheet mentioned that wiper resistance is 50 typical and 100 max.While I'm checking 2 chips and in of them each DAC has 39 wiper resistance and other one has around 44 wiper resistance. I did this test in 0 step. The wiper resistance is so critical in my application.
The question is, is the datasheet mentioned this value for upper steps or average? Does my test method is wrong?
In addition, the step resistance value is changing from first steps and last steps. (for example it is 40 in first steps and it change to 35 in around step 120 and so on . . .). Is it usual? What is the solution?