ceramic capacitor types

[johnsmith1261]

Hi!

I've run across two types of ceramic capacitors:
**broken link removed**
**broken link removed**

Are these two kinds functionally the same?
I've found no definite answer to this, although I've searched quite a bit...

Thanks,
j

 

[Miles Prower]

Ceramic capacitors are specced for capacitance, voltage, and temp-co. The first one you showed looks like it might be an NP0 type. These are useful as tuning capacitors, or determining the frequency response of active filters, or anything where you either don't desire, nor can tolerate, a great deal of frequency drift.

The second disc ceramic could be anything. These types are usually best for bypassing DC rails. or general purpose coupling capacitors where drift won't matter so much.

 

[johnsmith1261]

Thank you for your reply!
I realize that my original question wasn't clear enough, though.
The pictures I've linked show two different package types (the second one is usually referenced as "disc" type, if I'm not mistaken).
So my question is: when does the package type make any difference? If there's no difference, why do two variants exist?

Thanks,
j

 

[k7elp60]

The first picture looks like a mutilayer ceramic to me. That is the construction has several layers of ceramic with the capacitor plates on either side of the ceramic. In this construction a higher value can be achieved in a smaller package. The second picture is a disk with only one layer of ceramic. Most ceramic capacitors the value is listed with 3 digits and are usually in pf(picofarads). The 3rd digit being the number of 0's. For example 474 would be 470,000pf or 0.47uf

 

[Miles Prower]

Thank you for your reply!
I realize that my original question wasn't clear enough, though.
The pictures I've linked show two different package types (the second one is usually referenced as "disc" type, if I'm not mistaken).
So my question is: when does the package type make any difference? If there's no difference, why do two variants exist?

The package type doesn't make any difference. It's other properties that matter more. About the only possible advantage to the disc ceramic type is lower inductance, but that doesn't figure at frequencies below VHF.

 

[Sceadwian]

The package type does make a difference as it indicates the type of construction of the cap itself. There's a high degree of likleyhood that the internal construction of those two capacitors is different.

 

[Speakerguy]

The first looks like a multilayer ceramic. It is a high-K (or type II dielectric), definitely not C0G/NPO. 0.47uF is the value, and it's very rare to find an NPO ceramic that large. It would also be much larger (physically).

The second is a disc ceramic. It is also not C0G/NPO. Disc ceramics that are NPO have a black marking across the top of the disc. Also the value is too large again at 0.15uF. C0G/NPO ceramics are usually 0.01uF and smaller. You can get bigger but they get physically larger and more expensive.

 

[johnsmith1261]

Thank you for all replies!

To sum up, if I understood everything correctly, it seems that the only practical difference we can mention between disc and multilayer type through-hole ceramic capacitors is a bit lower inductance on the side of the disc style caps, but apart from these, they are identical...

Thanks, this question gave me some thinking from time to time, wasn't ever sure about this

j