AD5252 I2C pins on VDD+0.3V

Question I'd like supplying the AD5252 with +/-3Vdc instead of +/-2.75V, and using 0/+3.3V for I2C digital signals. Could I encounter some problems? The absolute max ratings for supply is Vdd to Vss =7V, and Vdd+0.3V for digital I2C bus. Thankings a lot for in advice Answer If you supply VDD = 3V, then ideally, you should be OK supplying 3.3V to the digital pins as it's within the VDD + 0.3V limit advised by the datasheet. However, you need to be mindful of the tolerance of the power supply, if the supply drops & the digital exceeds VDD + 0.3V, this could damage the part.

AD5252: Channal matching

Question What is the channel matching on dual digipot devices Answer The matching between Ch1 and Ch2 in the dual digital potentiometers is typically 0.1-0.2% and we usually specify ±1% as a maximum. (These specs can be found in the datasheets). This is dependant solely of the fabrication process. I checked with the product line and there is no one digipot family or part that has better performance over the others in this regard as they are all built on the same process. The ABSOLUTE resistance values of digital potentiometers vary over quite a large range +/-20% is not uncommon. If the customer has any concerns with the absolute resistance, they should consider one of the non-volatile memory digipots such as AD5252: The AD5252 features patented RAB tolerances storage in the nonvolatile memory. The tolerance of each channel is stored in the memory during the factory production and can be read by users at any time. The knowledge of the stored tolerance, which is the average of RAB over all codes (see Figure 16), allows users to predict RAB accurately. This feature is valuable for precision, rheostat mode, and open-loop applications in which knowledge of absolute resistance is critical.