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Website for alternate components?

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Advanced Member level 5
Jun 13, 2021
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Ever layed out a PCB, then found out that your chip(s) have gone obselete, and you need another one thats got the same footprint and characteristics?
Which is the website where you type in the component part number, and it gives you all the alternates?

Talking about obsolence or shortness of supplies? In most cases, obsolence doesn't happen unexpectedly, the parts use to be marked as "not recommended for new designs" or have low EOL numbers. Manufacturers often suggest a replacement.

Shortness of supplies is the problem of these days. You have 52 weeks or even more lead time for many standard parts like popular uC, FPGA or analog IC.

Generally speaking, there's rarely a 100 % equivalent replacement. You need to use application specific criteria when comparing characteristics. For me, distributor component search (e.g. from mouser and digikey) is a useable way to indentify replacement parts. There are also professional service providers like Some major instrument manufacturers have integrated SiliconExpert with their internal component database. They offer e.g. cross reference search for parts, but still need to compare parameters manually.
i do agree with you that parts do go obsolete and that is why in the design process, you need to be very careful such that you ensure that all the parts that you want to use in the schematic are all active parts. This can only be achieved by ensuring that you choose parts that are available with your favorite PCB manufacturer and her partners.
Thank you!


The problem with compatibility is:
* in which regard compatible?
* and who is responsible if they are not 100% compatible? (I think of a recall program of cars that maybe costs many million dollars)

Is pin compatibility, functional compatibility....

From my experience:
We once replaced a microcontroller with a microcontroller of a new production generation.
The manufacturer said it is 100% compatible.
But our production test failed because of the reduced supply current.
I don't complain about a reduced supply current. The manufacturer knew about the reduced current and told this in the datasheet.
But is it 100% compatible when a specified value changes?


In the end it should be always the original designer´s decision whether a "compatible" part can be used or not. Only he knows what parameters to look for.
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