Capacitors ... HELP

[adrianbodor]

What capacitors are the best type for use on bypass (i.e. IC between + and - )

I was thinking at metallized polyester (MKT)

Please help ...

[Zombie]

good ceramics aren't bad either

[adrianbodor]

I was thinking also at the ceramic type but i thinck the best option is MKT

What do you think ?

[roibm]

Uhhmmmm... Silver mica?

[00940]

bypassing what exactly ?

good MKT are decent

[Mr Evil]

Multilayer ceramic are generally considered the best for decoupling because they have low self inductance, thus maintaining low impedance at very high frequencies, which is exactly what you want for decoupling crap on the supply rails.

[AX816]

As it was said before multilayer ceramics are better at 'very high frequency'!...indeed but on power supply aplications regarding the fact that on common power lines (US or EU) the frequencies involved are much smaller i reccomend MKT ...very reliable,good tolerance ,the only drawback is the overall cost and i must admit that in this case the multilayers win.The multilayers are better suited for radio app or for freq rated beyond 1khz.But on audio low tolerance and low loses are to be regarded as remarcabe qualities.Moreover the extra low inductance is not really an asset in decoupling since the crap freq do not exceed in most cases of course the 1.5khz range...so a more mild capacitor is required.I've already used MKT and the results were more than satisfactory.But a good job can also be achieved using biased choke coils ...

[adrianbodor]

I want to mention that the circuit i intend to build is a stereo VU Meter with 40 Leds per channel (-40db to 0db) with LM339 comparators.

I decided to use MKT caps for bypass every IC between DC power lines ...

Here is the info about the VU Meter ...

http://www.tekniikka.oamk.fi/~archy/vu-meter/

Waiting answers and suggestions for those bypass caps ...

[Mr Evil]

For use in the PSU itself where the expected frequencies to be filtered are not that high (although of course there can be unexpected higher frequencies!), then I would be perfectly happy to use MKT, or any other type of capacitor, but for bypassing next to ICs the impedance at very high frequencies is more important to prevent oscillations. Thus I always use ceramic for that purpose. Of course other types may well work fine, but I would rather not risk building an unstable circuit merely for the choice of capacitor.

Tolerance, losses etc are not so important here since there is no signal passing through them.