[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Discussion About Filter Capacitors

I may be trying to over simply this. Each circuit will have different requirements
with load playing a part in that. I'm ready to get schooled on the topic.

I see most of our S100 circuits using .1uf and .33uf for filtering the VI and VO
on 78xx regulators. I believe this originates from the LM78xx data sheets.

These capacitors are typically electrolytic because of there ability
to filter out low frequency ripple and respond to fast load changes.
Electrolytic are not good at filtering higher frequency due to their higher ESR.

Tantalum's are used because they have lower ESR. Multilayer ceramic
also have low ESR and are suppose to be good because they have
excellent high frequency response and noise filtering.

I've seen comments that modern day 1uf can be used instead of .1uf.
The modern day ceramic 1uf's have much better noise performance and
low inductance than used to be the case.

So my question is, can I feel confident using ceramic disc capacitors
in this application instead of Tantalum? Tantalum tend to be a bit pricey.

Thanks in advance for your comments/suggestions/recommendations.

Don Caprio