PCN, PDN, EOL: what does each notice actually require me to do?
Reviewed · ICBOMS sourcing desk, Shenzhen
A product change notice (PCN) tells you a part you already use is changing — the same part number may keep shipping with different silicon, a different package finish, or a different fab — and the obligation is to assess whether the change affects your design, not to buy anything. A product discontinuance notice (PDN) is the announcement that production will stop, with a last order date; that date is the deadline that matters. An end-of-life notice means production has already stopped, and from that point the question is sourcing rather than ordering. Teams lose money by treating all three as notifications rather than as three different action items.
Product change notices: read for the parameters you depend on
A PCN often leaves the part number unchanged, which is why it is missed: the part still exists, so nothing appears to be wrong. What changes is one of the things your design might silently depend on — a die revision, a mould compound, a plating finish affecting solderability, a fabrication site affecting the electrical characteristics in a way that is within the datasheet envelope but outside your margin.
The work is a quick screening against what your design actually constrains, and a qualification decision if the change touches it. The useful habit is to route PCNs to whoever owns the design rather than to purchasing alone.
Discontinuance notices: the date is the whole point
A PDN carries a last order date and usually a last shipment date. Between those two, an ordinary purchase order still works — and after them, the same part becomes a search problem with a finite and thinning supply. This is the moment at which a lifetime consumption estimate converts into an order, and it is the last point at which the shortage can be solved by buying rather than by redesigning.
Two things commonly go wrong: the notice reaches a distribution partner rather than the OEM that actually consumes the part, and the deadline passes while the quantity estimate is being debated. Both are solved by routing: someone in the organisation has to own the date.
End-of-life: switch from ordering to searching
Once production has stopped, the parts that exist are the parts that exist. Availability is specific to the exact variant — package, temperature grade, revision — and it thins unevenly, so the base part number being findable proves nothing about the variant the board needs.
At this stage the useful questions are how much of the exact variant is available now, at what condition and with what documentation, and whether a cross-reference is acceptable to the design owner. Those three answers decide whether the board continues to be built as designed or needs a redesign.
Making notices land somewhere
- Get on the manufacturer's and distributor's notification lists for every part that matters — not just the expensive ones.
- Send PCNs to the design owner; send PDNs to whoever commits quantities.
- For PDNs, act on the date first and refine the quantity second; a rough order beats a late one.
- Track which parts are past end-of-life per product, so the search starts before a line stops.
Put this to work on your list
Send the part numbers or the whole BOM. Each line comes back with what can be sourced, its condition, and the cross-references where they exist — then the lines ship together.