Bypass capacitors, are either ceramic or poly film OK?

[Chris Wilson]

Is there a reason to choose either poly film or ceramic for bypass caps? I acquired a good stash of poly film caps at a rally, so could I use them, for example, for the bypass caps of 220nF in this circuit. Or should I get ceramics? Thanks. Note some bypass caps are shown with an asterisk to save schematic real estate.

[tggzzz]

The key characteristics required for decoupling capacitors are low inductance and low series resistance at the frequencies of interest. How low and what frequency are application dependent.

In general ceramics are likely to be better, but that's not absolute.

[wraper]

Depends on how particular film capacitors are made. Some may not be suitable for decoupling.

[katzohki]

I would tend to lean towards ceramics, but poly film "should do". Depending on the frequency and signal level of your circuit of course. For "general purpose" applications I wouldn't see a problem.

[c4757p]

Use ceramic for digital. Digital devices take sharp current spikes and require low-inductance decoupling. Stacked film capacitors will work in a pinch, but rolled ones will not.

Well, they'll "work" in the sense that that circuit would probably "work" without any local decoupling at all. They'd hardly help though.

[T3sl4co1l]

Won't make a lick of difference.