AD5272BRMZ-50 tolerance 15%

Hi BCA ,
The 15% tolerance applies when you're not using the Performance (R-Perf) Mode.
Have you tried to swap one of the AD5272 units with expected output to the one with significantly larger output?
Since it is working as expected with 25.5k fixed resistor, it may be a code/SPI issue, but the other 2 units seems functioning within your intentions.
If swapping with another AD5272 works, then we can isolate the problem (assuming the other components across 3 units are the same)

we are using the (R-Perf) Mode.  We will try to swap the pot form the unit with significantly larger output to see.

If you could clarify the tolerance with specific example that would be helpful

is the whole resistance range 15% so for example on a 100k pot total resistance could be 115k?

If the count is set at midpoint, would you be getting 1/2 of 100k or 1/2 of 115k?

i.e what would be the resistance and tolerance of the 100k device set at midpoint assuming R-Pref mode.

is 50k +/-1% accurate assumption?

Hi BCA ,
The AD5272 guarantees 1% end-to-end tolerance.
It would be correct to assume the midpoint to be 50k +/-1% in your example.

thank you.  we got to the bottom of it. 

thank you.  we got to the bottom of it.