ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

RE: ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

jc2048 — Sat, 10 Jun 2023 16:04:20 GMT

Interesting blog. You've already sold me on the idea of owning an ADALM2000, though it will have to wait until I've finished playing with the ADALM1000 that I've just bought.

Your traces nicely show the pair of resonances at the fundamental, the lower frequency series resonance and the slightly higher frequency parallel one. For the higher parallel one (the high impedance one), it looks from the trace like you might be scrabbling around right at the bottom of the ADC's resolution.

"Another very interesting thing I notice here is that the point of Peak Amplitude (resonance) corresponds to a 90 deg phase shift between output and input. Somehow I thought that there would be a 0 degree phase between the stimulus and response at point of highest resonance."

I think that will be down to the measuring instrument having capacitance at the input. Away from the frequencies where the crystal resonances are having an effect, you have a capacitive divider composed of the intra-electrode capacitance of the crystal and the input capacitance of the 'oscilloscope'. (Think of it as being like the way the frequency compensation for the potential divider of a x10 scope probe works.) So below the series resonance, the overall network response (including the measurement input) looks resistive rather than capacitive. You'd see much the same kind of thing with an LC network if you measured it in the same way.

RE: ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

DAB — Thu, 08 Jun 2023 18:38:21 GMT

Good test report.

I like the look of the software interface.

I may have to take a closer look at this device.

RE: ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

michaelkellett — Wed, 07 Jun 2023 17:12:06 GMT

Interesting, thanks for posting - I can see the pictures now.

There has been a recent thread on the HP groups.io group:

https://groups.io/g/HP-Agilent-Keysight-equipment/topic/99348298#135318

about measuring crystals - there were some very interesting comments with a lot of description of how crystals behave before it drifted off topic.

RE: ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

saadtiwana_int — Wed, 07 Jun 2023 17:02:22 GMT

Hi [mention:a5312e9762dd4699ba5d3876da34ffe5:e9ed411860ed4f2ba0265705b8793d05] , [mention:89905ffecc134446a07e462576154a4a:e9ed411860ed4f2ba0265705b8793d05] , [mention:193ac2434c814a24b46635a2210baec1:e9ed411860ed4f2ba0265705b8793d05]

Thank you for pointing out. This issue has happened to be in the past as well. At that time I was told it may be because I had dragged-dropped the images into the editor and had recommended that I use the INSERT --> Image feature instead. This is what I used this time, but seems to be happening again.

Anyway, I just finished removing and re-uploading ALL the images again. Please let me know if it's still happening or if you can see all images now.

-Saad

RE: ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

dougw — Wed, 07 Jun 2023 16:43:38 GMT

As mentioned by others, 10 of the images are not visible - we "do not have permission to access" that directory.

RE: ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

javagoza — Wed, 07 Jun 2023 16:38:48 GMT

There are a lot of images that don't display well, at least in my Microsoft Edge Windows 11 browser.

RE: ADI ADALM2000 - Exploring the mysteries of a Crystal Oscillator

michaelkellett — Wed, 07 Jun 2023 16:38:41 GMT

Most of the earlier pictures in your blog just shows as "image" like this:

but later ones are fine.

I'm hoping you can fix this because its a bit hard to follow without [emoticon:c4563cd7d5574777a71c318021cbbcc8]