2021-08-10 06:14 PM
I am finding it difficult to source an external crystal for the Nucleo-64 board (The F103RB). The footprint for the X3 crystal calls for a lead pitch of 5.08mm however this seems to be very uncommon. Most of the crystals out there specifiy a lead pitch of 4.88.
Now, looking at the user guide for the Nucleo-64 boards, it mentions a part from HongKong crystal, 9SL8000016AFXHF0, which is:
Perhaps there an updated PCB design that has not made its way into the CAD resources section of the Nucleo-64 product page for the Nucleo F103RB?
Solved! Go to Solution.
2021-08-12 09:08 AM
Hello,
As an HC-49 crystal can easily be inserted by hand on the Nucleo board, even with this 5.08mm spacing, I guess nobody really encountered a problem before.
I entered a ticket, but, the design is "old", and I don't think there will be an update.
2021-08-10 06:33 PM
The HC49 package has 4.88mm nominal lead distance with a ± 0.2mm or so tolerance. I doubt you will find nominal 5.08mm crystals, but the standard package should fit in the footprint, even if it is slightly off.
2021-08-10 07:21 PM
Thank you for such a quick reply. My search also yielded nothing, except for a single oscillator with a lead pitch of 5.08mm.
As a former PCB designer, this would have been an absolute no-no for a PCB design to specify a foot print of 5.08mm and having a "she'll be right" approach.
Anyway, I would hope the ST guys out there might find some time to update the PCB footprints
2021-08-12 09:08 AM
Hello,
As an HC-49 crystal can easily be inserted by hand on the Nucleo board, even with this 5.08mm spacing, I guess nobody really encountered a problem before.
I entered a ticket, but, the design is "old", and I don't think there will be an update.
2021-08-12 10:14 AM
Very old board, no one is going to revisit, and some of the newer NUCLEO-64's have entirely different footprint for the crystals, moving to surface mount
2021-08-13 03:04 PM
Thanks Mike for entering that ticket however, like you said it probably won't be looked into.
It's just a pet peeve of mine that something like this would have gone through a PCB review and overlooked.
Anyway I have bought up some HC-49 crystals so we'll see how it goes.
Cheers for the all the help