dkonigsberg
commented
1 day ago After a little digging, this seems to be just a manufacturing change.
While not linked in the Email, Digi-Key does have a document talking about it: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/6448/BLAS-06WDEF500.pdf
Which then links to the following document on Microchip's website: https://www.microchip.com/product-change-notifications/Data/BLAS-06WDEF500/PCN_BLAS-06WDEF500_Recommended%20Replacements.pdf
This gist of this is that we simply need to update our BOM such that:
MCP4017T-104E/LT becomes MCP4017T-104E/LTY
This replacement part is not yet listed with vendors, but is effectively the same thing with a different finish on the leads.
Just received a part life notification from Digi-Key, indicating that the MCP4017T-104E/LT digital potentiometer is now end-of-life. Need to investigate whether this part is really being discontinued, or if its just a vendor database rule being triggered by some change in supplier part numbering specifics.
This part is used to control the LED drive current on the DensiStick.
Ultimately, either a drop-in replacement needs to be found, or an alternative solution. So this will be a BOM change or a circuit change.
In practice, the only drive current settings actually being used are "maximum current" (minimum resistance) and "minimum current" (maximum resistance). A digital pot is the easiest, cheapest, and most flexible way to accomplish this, but not the only way. So anything that makes it easy to switch between 2-3 resistance settings on the LED driver's RSET pin will work here.