ceramic vs tantalum caps

[coolhand21]

ceramic vs tantalum as a filter caps

I need to remove noise above 10mhz, which type would be perfered?

thanks cool

 

[ckshivaram]

for high frequencies it is always preferred to use tantalum capacitors.............

 

[coolhand21]

is that because of the series inductance

 

[ckshivaram]

check this .. it has the explanation

**broken link removed**

Tantalum and aluminum electrolytic capacitors intrinsically high ESR and ESL dramatically reduce their usable capacitance at high frequency.

 

[dick_freebird]

You can find tantalums with really good ESR/ESL, and you can
find ceramics with lousy. You need to pay attention to the
details and try to use the manufacturer SPICE models to
assess, not go by some weak rule of thumb.

 

[FvM]

You can find tantalums with really good ESR/ESL, and you can find ceramics with lousy.

I think, the latter will be much more difficult, with parts recently available on the market. Most differences between ceramic cap types are related to voltage dependancy, TC and loss factor. Referring to the original question, for rejecting 10 MHz, ceramic caps are usually cheaper, more efficient and typically smaller.

 

[SherpaDoug]

1) I assume you are talking about 10MHz (megahertz), not 10mHz (millihertz). I have worked in oceanography where millihertz (1/17 minutes) is actually used to describe ocean waves.

2) Physically smaller caps let you reduce the inductance of the connecting traces. At really high frequencies (>100MHz) the trace inductance can easily be higher than the cap ESL.

 

[coolhand21]

I did not expect a different between the two types (the tan was 2.2uf and the ceramic was 4.7uf).
The tantalum in this case was clearly better.

cool

 

[FvM]

The tantalum in this case was clearly better.

Better in which regard?