Capacitor with low ESR

Ok clearly you are not interested in helping. So please just clear the stage for whoever IS!

Not interested in helping lazy people!

I’m not lazy! I can’t find a filter on the site! There is no filter on the site for ESR! Like I already said the very first post! Either you can find it (and if you share your method I will be thankful too) or you can’t!

For a start, this question is unrelated to KiCad.

Secondly, ESR is seldom offered as a searchable/filterable parameter as it is frequency dependent. Select a capacitor and read it’s datasheet (Hint: look for a graph.)

Thirdly, learn a little about electronics before you layout your next board.

And what you are asking for:

isn’t what you need.

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I suppose it would be difficult to find ceramic 1uF capacitor with ESR as_high as 500mOhms.
I suppose typical woułd be less then 100mOhm.
Typical problem with ceramic is that they have to low ESR and some LovDrops are not stable and to get them stable I add R in series with C.

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First of all. There is a reason this is labeled as manufacturing. I am aware this has nothing to do with KiCad but thanks for the information.

Second of all: ESR is seldom offered… is exactly my point!

Third of all: I tried looking in the datasheets of the capacitor I had in my BOM previously but there were so many capacitors that I couldnt ever realize what graph represented my specific one!

4: I learned alot about electronics. More than you think. I am doing my final project in electrical engineering with an average score above 90 (doesn’t matter how much exactly) in the courses I took. However, there is no course for PCB layout in my degree and my instructor won’t help. Jeez! I thought I would be able to just ask a question on a forum but look at this! I have to admit I am disappointed.

If I said that’s what I need obviously I know already?!

Fourthly, learn how to search for components :slight_smile:

I had a vague memory that “polymer capacitors” were good in the ESR department.
So I went to mouser, typed in “polymer capacitors”, added some other filters (1uF, 50V) and among other things also a column with ESR popped up. ESR seems to start @ 200mOhm.

https://eu.mouser.com/Passive-Components/Capacitors/Polymer-Capacitors/_/N-bjuf7?P=1z0wrj5&Keyword=Passive+Components+Capacitors+Polymer+Capacitors&FS=True&Ns=ESR|0

Thanx Piotr:

Are you saying that almost any cap will be ok at this size?

Thanx but those are not 1206. Furthermore: 1206 is not available just 1210.

When searching at digikey, for polymer capacitors also a list for ESR pops up.
ESR starts in the low mOhm.
https://www.digikey.com/products/en/capacitors/aluminum-polymer-capacitors/69?k=polymer%20capacitor

And as this seems to be a one off (school?) project, don’t worry too much about the size of the thing.
Those radiall through hole caps also fit SMD pads with a bit of bending.

And next time:
Get your components in order before you design the PCB.

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I am using SMD only. Thanx. After filtering for 1206 the closest cap size to 1uF available was 4.7uF. Will I be ok using 4.7uF?

I think so.
It is sometimes not easy to find exact information in datasheet, and it is frequency dependent so I don’t expect Digi will search it for me.
Long time ago I was using tantals. Then earthquake (2002?) made them anaccessible so I switched to ceramic and found the problems with them - too low ESR.
Small SMD tantals (not sure 22uH) as I remember have ESR about 700m. When you order LovESR tantal you can get 200…350m. With ceramic it is possible that you get 10…20m. You have to check specially LovDrop linear stabilisers if they are stable with so low ESR.

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I’m trying to be as fast as I can and then read once more. 22uF of course.

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Ceramic capacitors tend to have a very low ESR, but are often < 1uF.
However, you can easily stack a few on top of each other, It will be hard to see more then one is stacked.

Sometimes they are even sold this way. Same footprint as 1206, but a lot higher then normal, and even with some “springyness” built into the metal bracket to overcome the mechanical brittleness of ceramics.

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Do you think that is the reason there is no ESR filter for ceramic caps? Because the ESR is anyways very low on ceramic?

  1. just FYI: never produce a PCB before checking your BOM full availability… this is a very basic rule!
    and you can notice that you have already warned on that…
  1. never drop help from very helping people (many who replied here are from the most helpful people at the forum)

just my 2c

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Don’t understand - you don’t see 1uF.
When I filtered 1206 1uF 50V I got 299 results at Digikey.

Ok that explains it. I am at mouser. But are you at tantalum or at ceramic?

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Tantal typically has a higher ESR. So if you want high ESR you might want to look into them. (Only works if you can tolerate polarized caps in your design. This is a decision we can not make as we are missing information.)

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I need lower than 500mOhms ESR. So no. I need low ESR not high.