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I do hope this post is still within the boundaries or spirit of this forum and perhaps this question is best suited for the chat instead.

I'm sure we all are experiencing (in one form or another) the industry-wide part shortages for discrete MLCC (caps) and resistors, in like the 0402/0603/0805 packages. This part shortage has forced us into sourcing alternate parts (sometimes less than ideal) in a effort to continue design work and shipping product.

Here are my two questions. Even though the only research I put forth is Google/web searches for work-arounds; but do any of you designers have any creative methods or ideas in terms of part sourcing or design considerations for providing (mostly) by-passing/de-coupling using 0.1/0.01uF 25V-100V X7R/X5R 0603s in both current product as well as new designs? Should I continue to design in hard-to-find MLCCs and hope this storm blows over sometime soon?

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  • \$\begingroup\$ There are no alternatives. Some warehouses still have plenty though, just not the brand you'd like. \$\endgroup\$ – Jeroen3 Apr 25 '18 at 18:40
  • \$\begingroup\$ Where did you get the info about MLCC shortages? In "Fake news"? Why there should be any shortages if there is a demand? \$\endgroup\$ – Ale..chenski Apr 25 '18 at 18:41
  • \$\begingroup\$ A 0.1uF cap in 0603 size holding 100V is a real stretch. Use 0805 or 1206 size instead. \$\endgroup\$ – Ale..chenski Apr 25 '18 at 18:49
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    \$\begingroup\$ On my most recent respin I only found stock issues with caps that pushed the envelope for their package, i.e. 22uF @ 0603, 470nF @ 0201, etc. Your search for 100V 0603s is another example. I just relaxed values where I could and found plentiful stock that way. I'm sure others don't have that luxury though. \$\endgroup\$ – jalalipop Apr 25 '18 at 19:06
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    \$\begingroup\$ @AliChen The MLCC shortage is very real. You'd encounter it almost immediately trying to buy parts for any volume board with small package caps. Digi-key even puts a note about market demand on all of the MLCC pages. A quick Google search will confirm this for you. \$\endgroup\$ – jalalipop Apr 25 '18 at 19:09
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If you can respin your board, there are few things you can do:

  • As stated in the comments, use larger package. 0.1uF/100V might be easier to find in 1206 than 0603.

  • Use 2 (or more) lower value capacitors instead of one higher value capacitor. Advantage: lower ESR/ESL, Disadvantage: Lower ESR/ESL, depends on your design.

  • If allowed and properly evaluated, use different dielectric. Y5V might be easier to source than X7R.
  • If you need the higher voltage, use 2 capacitors in series.You will need balancing resistors, which will consume power.
  • If cost is not an issue, use Tantalum or other exotic types. Again, this opens up some major reliability concerns, so tread carefully.
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  • \$\begingroup\$ Good stuff, I will take note;-) \$\endgroup\$ – Steve Apr 25 '18 at 19:34
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    \$\begingroup\$ So I relaxed my V-rating, bumped up to 0805s, kept the X7R dielectric (I was using 50V/100V 0603s to keep my library count as low as possible and maximize buying leverage) and can now find more options. Thanks. \$\endgroup\$ – Steve Apr 25 '18 at 20:40
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Use polymer type caps. They outperform MLCCs in a lot of parameters. See https://eu.industrial.panasonic.com/sites/default/pidseu/files/pan_18072_whitepaper_mlccvspolymer_web.pdf

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  • \$\begingroup\$ Boy, after reading this white-paper it appears that poly caps may be the silver bullet. When comparing nominal capacitance variance vs DC bias (an artifact that I am still trying to fully understand) those poly caps are superior. This is a big deal in motion-control and stepper drive circuit design. \$\endgroup\$ – Steve Jun 20 '18 at 13:31
  • \$\begingroup\$ A drawback of poly caps is the relatively large leakage current. So they are not a good fit for battery powered applications. But other than that, they are just great (and available!) \$\endgroup\$ – Stefan Wyss Jun 20 '18 at 13:56

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