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I think a lot of that was from old data sheets... look at the MAX 232. The old data sheets show 1uF tantalums, now they use 0.1uf (non-tantalumn)
> From: lcy...@bellsouth.net > To: n8vem...@googlegroups.com > Subject: RE: [N8VEM-S100:6383] Discussion About Filter Capacitors > Date: Sat, 21 Feb 2015 03:41:35 -0500 > > Ceramic disc caps (I have read) are not the best for bypass use nowadays, > though they used to be in common use. > Monolithic caps are usually much better for this and take less real estate > on the PCB. > Also, I believe the older 78xx and 79xx data sheets specified tantalums? > Faster transient response, presumably- which helped stabilize the regulator IC. > > Leonard > > -----Original Message----- > From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Don Caprio > Sent: Friday, February 20, 2015 2:46 PM > To: n8vem...@googlegroups.com > Subject: [N8VEM-S100:6375] 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 > ilv...@gmail.com > > -- > You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. > To unsubscribe from this group and stop receiving emails from it, send an email to n8vem-s100+...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. |