Contents
Which is more elastic rubber or quartz?
A substance is said to be more elastic if it does not deform easily. In other words, if a substance does not lose its shape easily, it is more elastic compared to other substances. Quartz is more elastic because when stretched, it does not deform and returns to its “original shape” and size very quickly.
What is the formula of density of a cubic crystal is?
Hence, the density of a body-centered cubic unit cell is equal to 2 x M / A3 x Na. Face-Centered Cubic Unit Cell: The total number of atoms present in a face-centered cubic unit cell are four. Hence, the density of a face-centered cubic unit cell is 4 x M / A3 x Na.
What are the capacitors on a PCB Crystal?
C1 and C2 are the two capacitors that you see attached to the crystal, but you might be wondering what Cstray is. Unfortunately, every trace, every lead on your component, just about everything on your PCB has some stray capacitance. The total of these values is represented by Cstray.
What should be the ratio of capacitors to crystals?
A commonly tossed around rule of thumb is to start with a pair of capacitors two times the CL of the crystal, which will get you to CL. In this case, that would be 2*8 pF = 16pF for the capacitors.
How to choose the right capacitor for your cstray?
If you think the stray capacitance is a bit lower, say 3pF, you might try a 10pF capacitor: There’s an obvious tradeoff between choosing a standard capacitor value, and having a good idea of what your Cstray is, but the above formula should at least explain HOW to determine what value those capacitors should be relative to your crystal.
How can I tell if my capacitors match my Crystal?
We know CL since it’s stated in the crystal datasheet (8 pF), and we know Cstray (say ~5 pF), so all we need to do is test our value for C1 and C2 to make sure that it will match CL taking into account Cstray. A commonly tossed around rule of thumb is to start with a pair of capacitors two times the CL of the crystal, which will get you to CL.