Crystal vs oscillator?

[sb_st]

Hi! I’m starting design of a new board, on which I’d like to use an stm32h7 device. My board will also include an audio codec and usb hs phy.

Historically I’ve used crystals to drive HSE of the mcu, but some reference designs I’ve been studying show the use of cmos oscillators to drive the clock. I am curious about the trade offs of this, or how/when I should prefer a crystal over an oscillator?

thank you!

[EThom.3]

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@Andrew Neil wrote:

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I guess the thing to bear in mind here is that only the problems get posted to the forum - the thousands of people whose crystals just work fine don't keep posting to say, "my crystal is working fine!"

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Maybe we should begin posting positive and happy stuff like "I just made this protoype, doing this and that, and it works great!" :D

I agree with @RobK1 . We don't have to permanently choose one or the other. Use whatever works best for the design at hand. (Or if it is like in the early 2020's: Choose whatever is still in stock...)

[sb_st]

Wow, thank you all so much! This is all awesome information.

I had indeed found that SiTime article, but to echo @Andrew Neil’s thoughts, it feels to me more like marketing masking as education, and in any case I worry it over-indexes on cost, which surely is not the only basis on which to weigh crystals against oscillators? @EThom.3 touched on the issue of EMC concerns, and that seems relevant to a project like mine, which is lightly mixed-signal. I don’t have any prior experience with most of this, so this is a learning project for me.

In any case, thanks for the resource links; I will do some more exploring to try to get some better insights…

[EThom.3]

I you end up using a crystal, and want a second pair of eyes on your design / component choices, please feel free to send me a private message. Happy to help.

[sb_st]

Incredible offer of you, thanks so very much!