Best decoupling Capacitor?

[livenicely]

which type of capacitor is best for decoupling?
Ceramic
Polyester
Metalfilm

[Joachim Gerhard]

I decouple opamps with 0.1uF Röderstein 1837 MKP and 1nF NPO-COG ceramic.
Sometimes is use aditional 100uF to 330uF elcaps from Nichcon KZ, Elna Simic2 or Pannasonnic FM. I do also a 0.1uf from the plus to the minus supply locally. Sometimes this single cap is all that´s needed.

[Atilla]

Decoupling what though. Some things need more attention, some things less.

At any rate a 10-100uF el. cap + a 0.1uF polyester/polyprop is appropriate. For some opamps a low-value NP0 ceramic directly at the pins is needed, but the datasheets tell you what's necessary anyway.

[frank1]

Originally Posted by livenicely

which type of capacitor is best for decoupling?
Ceramic
Polyester
Metalfilm

All of them (including electrolytic) when used in the right circumstances.
Pointless excercise.

[AndrewT]

I tend to not use ultra low ESR.
Ceramic and MKT are fit for this duty
Some specifically say that MKP and C0G are not suitable for decoupling, that the ESR is too low and increase the risk of ringing.

[Joachim Gerhard]

You could then put a small resistor in series. Well, this is shot in the eye through the head as we say here but then you can enyoy the quality of the better parts.

[random007]

Multilayer ceramic (aka monolithic) are often used in digital circuits due to tiny size and excellent high frequency characteristics.

Audio seems to favour 100nF MKTs, sometimes coupled with larger electrolytics as space allows.

'Metal film' and 'polyester' are two different aspects of a capacitor construction (conductor and dielectric) rather than capacitor kinds in their own right. MKT type capacitors are made from metalis(z)ed (aka metal film) polyester.