Custom T3.5 - MK64FX512VMD12 or MK64FX512VDC12?

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J

jensa

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Hi all,
I'm looking into making a custom Teensy 3.5 board, but the MK64FX512VMD12 listed on https://www.pjrc.com/teensy/techspecs.html is out of stock and Mouser estimates deliver to 9/21/2021. Does anyone here know if MK64FX512VDC12 is a possible replacement? Paul lists the MK64FX512VLQ12 (LQFP) as a replacement but I'm a little hesitant given the low volumes of this version currently available.

Also - 52 weeks lead time from NXP is a bit of a turn-off?

J
 
I think you misunderstood @defragster. That's not many and in that listing, the same 465 ic's show up multiple times. (I used Octopart for my search) For the Teensy 3.2 chip, there are several vendors with many thousand available. For the T3.5 ic, it's in the hundreds and that's worldwide. My customer currently do batches of 250 or 500 pcs for their existing product. I'm now designing a new product for them with a design based on Teensy. Seeing that less than a thousand ic's are available & most vendors not getting stock until after summer can certainly be a problem.

So thus, I'm curious if the MK64FX512VDC12 could be an alternative?
 
Seems all but the p#1 unindicated large quantity desired was understood.

Certainly a question for Paul about adding an alternate chip to support ...

Wow even the T_3.6's MK66FX1M0VMD18 is in similarly short supply.
 
The "VDC" package part hasn't been tested. It might work, or might not. The only way to really know would be to design & build a PCB and test it. Odds seem pretty good it should work. But if it doesn't actually work you'd be stuck and have to scrap it and just start over with the "VMD" or "VLQ" parts which are known to work.

That is, if you can even make a layout for that VDC part. The 0.65 mm pitch BGA is really difficult to route using a normal PCB process! It is possible to route a subset of the pins using a PCB process at the upper end of "normal" fabrication, using 4 mil traces and 8 mil drill and 4 mil annular ring (so vias inside the BGA are 16 mil diameter). Using only 4 layers tends to impose a lot of routing issues that usually result in a larger PCB. But if you need to "escape" too many of the BGA pins or even just subsets too densely packed, this sort of BGA usually means going to a much more expensive "HDI" type PCB, because even with those upper end PCB specs, you need to find a strategy to stagger the via pattern so wires can route between then on the inner layers! As a general rule, 0.8 mm pitch BGA is considered the "sweet spot" where you get the smallest chip with routing still possible using normal PCB specs. BGAs with tighter than 0.8 mm pitch are usually soldered to HDI boards with features like laser drilled vias and filled/plated though vias, and much tighter tolerances on traces & spacing.

And yeah, lead times and availability on almost all parts right now are tough. The whole semiconductor industry is really messed up for 2021. :(

If you'll only need a moderate quantity (less than a few hundred) of MK64FX512VMD12 chips, PJRC might be able to help. We plan far ahead and have a good number in our inventory. I'm pretty sure we could match Mouser / Digikey pricing. Email Robin directly if you are sure you'll need MK64FX512VMD12 chips, with a rough idea of how many and when.
 
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