Hi,

We are using AD5272 digital potentiometer. From Table 2 of Datasheet, in R-perf mode, resistor tolerance is 1%, when code range is from 0x078 to 0x3FF. 2% R-Tolerance when code from 0x037 to 0x3FF. So, if we use from from 0x0 to 0x3FF, what would be the expected tolerance percentage?

One more question is, what is the maximum wiper resistance of AD5272. There are two conflicting values in datasheet. Wiper resistance typical is 35 and maximum is 70 ohm in page 3, with code=zero scale. And in page 23, it is written that "In the zero-scale condition, a finite total wiper resistance of 120 Ω is present." which one is correct?

regards,

Sneha

Hi Sneha,

Looking at table 3:

If you use any code between 0x078 and 0x3FF on the AD5272, you can assume a maximum of 1% end to end tolerance (worst-case).

If you use any code between 0x055 and 0x3FF on the AD5272, you must assume a maximum of 2% end to end tolerance (worst-case).

In your case, since you are using a code outside the table 2 codes, you must assume the 15% tolerance is the worst case tolerance.

I'll check what the writer meant with the 120Ohm comment but please use the specifications in table 1 as these have been agreed by the AD5272 team when the datasheet was published.

Kind Regards,

David