About Silicon Revision.

[Rob_975]

Hi.

Somebody knows which is the difference between PIC suffix I/P and
I/PTSRL?

The datasheet of the 18F87K22 says that TSRL is silicon revision A3.
Now, since Digikey has both of them, is the A3 the newest or the oldest?
I any case, I would say that the newest rev should be bought.
Right?

Rob.

[ckielstra]

It is seldom that Microchip marks the silicon revision number outside on the chip package. I don't know why, probably to ensure they will not be left with old stock.

Indeed the Datasheet marks the RSL code as silicon revision A3.

Normally you can only check the silicon revision when reading the device ID with a programmer tool or ICD.
Then in the chip errata document you can look up the conversion from device ID to silicon revision.
Most recent silicon version seems to be C1. So whenever possible you want to get the newest revision and not the A3. However, it is unlikely your supplier will be able to guarantee the revision you will get.

[Ttelmah]

My guess would be that a specific large customer designed their code when the chip was first launched, and want to be able to guarantee that revision changes won't affect them. Hence Microchip are still manufacturing the original revision, with a separate part number for this.
I have seen this before on one of the RFID chips, where the later silicon required code changes, and because the units were being used in millions off, with a five year source contract from Microchip, they agreed to guarantee the supplied silicon revision remained the same for the duration of the production contract. The chips carried the company name as two initial characters in the part number, so I'd guess that 'RSL', might be similar. In that case the chips were directly from Microchip, but some were then put onto the market (surplus production), probably just to allow other customers with similar requirements to use them.

Best Wishes