Xtal Selection.

[mbmail4]

Posted on January 25, 2016 at 02:07

Hi.

I have been looking over some of ST's EVAL board, and the one thing I notice is that all of the ones I've looked at ie STM3210x_EVAL,STM32100x_EVAL, and the Nucleo evals, all use a quarts xtal in a through hole can design (some don't populate the board, but its a can footprint on the PCB). I have always used a surface mounted TXD quartz crystal of about a 12pF load on almost everything I've put together using a micro, but I've never done this for a ST micro. Is there a reason for this? Isn't it cheaper to use a surface mount footprint design? or is there an electrical reason to use a can type? Thanks.

[Tesla DeLorean]

Posted on January 25, 2016 at 03:06

No I think it is purely a cost/availability thing. We have used SMT parts exclusively here.

If you look at the 469I-DISCO and 746G-DISCO both the F103 (ST-LINK) and target STM32 parts all use SMT crystals. These look to be significantly more expensive PCB designs than the F0-DISCO

[mbmail4]

Posted on January 25, 2016 at 05:30

Thank you Clive. I though perhaps that might be the case. In any case the Nucleo's have plenty of board space.

Regards