Intersil (or Renesas) has rendered the ISL23345 digital potentiometer obsolete. They suggest the ISL23325 as a replacement, but for those still needing 4 pots in one package, the X95840 is a more suitable choice.
Near the top of the company’s product page for the ISL23345 digital potentiometer, there is a message saying that this part is obsolete. Included is a suggested replacement, which I did NOT use:
Not recommended for new designs. Suggested replacement: ISL23325.
There is nothing inherently wrong with the suggested part; I am sure it works just as well as the original. However, it downgrades you from 4 (four) potentiometers per package to only 2 (two) potentiometers per package, hence the part numbers being identical save for the 4 being replaced by a 2.
For those still looking to reap the benefits of 4 pots in a single package, the X95840 is a great solution. It is especially convenient because both it and the obsolete part use the same 20TSSOP package, ableit they have different pin layouts.
To be sure, the 4-pot replacement I suggest only offers resistance options of 50kΩ and 10kΩ total resistance. Their suggestion offers total resistances of 10kΩ, 50kΩ or 100kΩ. The operating temperatures of mine are also not as superb, but that will not matter for most.
There are a few key feature differences and similarities between the old ISL23345 digital potentiometer and the new X95840 digital potentiometer. I did not include their suggested replacement (ISL23325) in this comparison list because most engineers who were already using the old pot want to know the differences between it and another 4-pot replacement.