EEVblog #1089 - XTAL Oscillator Teardown

[EEVblog]

What's inside a DIP crystal oscillator module?
A 2 minute teardown turns into 17 minutes, because, well, it's Dave. Includes a revisit of the bypass capacitor video.

[kcozens]

Hm... I get first post?   I have used these devices for years but never stopped to think of what is inside one of these devices so this video was very interesting to watch. I did some digging around and I found a datasheet for the IC used in the small square oscillator package. The part number is SM5613N1. You can see the datasheet for it at http://www.digchip.com/datasheets/download_datasheet.php?id=877041&part-number=SM5613N1

[SNGLinks]

The reason they use a 8 MHz xtal and divide down is that a 1 MHz xtal would be too large to fit in the package.

[EEVblog]

Why then is the thumbnail Dave shows of a 32K crystal oscillator that seems to be of the same size? And why are watch crystals so tiny?

It's not a 32KHz crystal, it's in the MHz range.
32KHz watch crystal use a tuning fork style.

Why would you choose a crystal over an oscillator? Or vice-versa?

Oscillators will generally have a higher frequency divided down, so EMC issues, and potentially consume more power.
Oscillators are easier to implement in a system.

[mikerj]

I'd have thought the springs were to reduce stress on the crystal e.g. due to differential expansion over temperature.   The crystal looks a bit too light for those springs to absorb much of a shock.

[coldfiremc]

If this is a kind of colpitts oscillator, I really miss the other capacitor. Is inside that IC? is this another circuit?

[Fungus]

32KHz watch crystal use a tuning fork style.

Teardown!

Also: Accelerometer!

[@rt]

A vintage radio crystal I recently pulled apart used a very heavy spring
to push each electrode very tightly against the crystal wafer.
Only the disassembly releases the tension of the spring.
I can’t really tell if that’s what’s happening there.

[RoGeorge]

I remember on the youtube page of this video two very, very long comments from somebody who worked in the Xtal manufacturing industry. He was talking about interesting techniques, with lots of hands on experience and historic details. It was the first comment, with a few hundreds thumbs up.

I still get notification from Youtube about replies to those long comments, but if I open the youtube page, I can not find that comment any more. Tryed another browser, no cookies , logout from youtube but with no luck finding those comments again.

Is it something wrong with the youtube site, or those comment were deleted? Can anybody else see those two long comment, please?

[glarsson]

This film about xtal manufacturing is old but the advantage is that you can actually see the steps needed.

https://youtu.be/b--FKHCFjOM

[thm_w]

I remember on the youtube page of this video two very, very long comments from somebody who worked in the Xtal manufacturing industry. He was talking about interesting techniques, with lots of hands on experience and historic details. It was the first comment, with a few hundreds thumbs up.

I still get notification from Youtube about replies to those long comments, but if I open the youtube page, I can not find that comment any more. Tryed another browser, no cookies , logout from youtube but with no luck finding those comments again.

Is it something wrong with the youtube site, or those comment were deleted? Can anybody else see those two long comment, please?

http://ytcomments.klostermann.ca/scrape
I don't see it with this tool, could be deleted or could be youtubes comment system being terrible as usual.

[TheNewLab]

Has anyone tried to run the XTAL after opening it up?? or desolder that IC and use it on another circuit?  humm,  Should I try that? or remove the crystal and see it anyone can get it to work? That last one may being heading into impossible...

[modernstyle]

I remember on the youtube page of this video two very, very long comments from somebody who worked in the Xtal manufacturing industry. He was talking about interesting techniques, with lots of hands on experience and historic details. It was the first comment, with a few hundreds thumbs up.

I still get notification from Youtube about replies to those long comments, but if I open the youtube page, I can not find that comment any more. Tryed another browser, no cookies , logout from youtube but with no luck finding those comments again.

Is it something wrong with the youtube site, or those comment were deleted? Can anybody else see those two long comment, please?

http://ytcomments.klostermann.ca/scrape
I don't see it with this tool, could be deleted or could be youtubes comment system being terrible as usual.

This tool doesn't seem to work anymore and the dev says there's no future support coming.
Here's an alternative: https://seobots.io/bots/youtube-comment-scraper