SMD-electrolytic capacitors

[Boncuk]

In order to minitaturize an already working circuit based on discretes I need some information about SMD-electrolytic caps concerning shape, dimensions and the solder pattern to be used with different value caps.

So far I couldn't find any useful information. Just the outline dimensions are not satisfactory to "build" a device for further use in Eagle layout editor. Also looking at different offers of electronic distributors there seems to be a stop at a maximum of 100uF, limited to 16V. Is there such thing as 100uF/25V?

The circuit is used in cars and requires at least 100uF at the input of the voltage regulator. A 16V type would just be very close to its limits and thorough filtering of spikes from the alternator would take more room than the circuit itself.

Does somebody here know a link where to get all the required information. A link towards SMD-tantalum-caps would also be appreciated.

Thank you and regards

Hans

P.S. I already checked at WIMA Germany, but their offer ends at 6.8uF.

 

[dknguyen]

Search Digikey and look at the datasheets that come up? They're everywhere.

I don't know where you're looking, but I easily found a 100uF, 250V capacitor (on Digikey).

 

[justDIY]

if you're referring to aluminum electrolytic caps, there's no real benefit to smt, other than you save a few holes from poking through your layers. they aren't any smaller than their leaded ancestors, and they're feeble too. their large size and relatively small mechanical connection make them easy targets to get nocked off a board.

you should be able to find tantalum caps from any good distributor, but the high capacitance and high voltage ones are darned expensive.

 

[jpanhalt]

With Eagle, you can go to the edit lbr dialog and look at the packages. I have found that to be slow and cumbersome when I am looking for a part to fit a particular space. And, there is no assurance the parts available to you are in the Eagle libraries.

Therefore, I do as dknguyen suggests and use the Digikey catalog to find the size, then Eagle to do the rest. John

 

[Funny NYPD]

Or you can get a catalog book from Digikey or mouser. It is convinent to find in a book sometime.

 

[kchriste]

You could also look into multilayer ceramics like the 47uF 25V TMK432C476MM-T (1812 size) capacitor.

 

[Boncuk]

Search Digikey and look at the datasheets that come up? They're everywhere.

I don't know where you're looking, but I easily found a 100uF, 250V capacitor (on Digikey).

Hi dknguyen,

sometimes it becomes a real problem connecting properly to Google or any other search engine. All the pages are displayed using Thai writing which I don't know and don't want to learn either.

Thanks for your help.

Regards

Hans

 

[justDIY]

sometimes it becomes a real problem connecting properly to Google or any other search engine. All the pages are displayed using Thai writing which I don't know and don't want to learn either.

set your google preferences to return results in english.

another supplier to check is farnell-newark, they seem to have a lot of different international offices

**broken link removed**

 

[Boncuk]

set your google preferences to return results in english.

... before or after having learned to read Thai letters?

 

[jpanhalt]

Do you mean you can't make google come up in English?
You might try another search engine, such as dogpile:
https://www.dogpile.com/
John

 

[justDIY]

Boncuk,

How can I get back to the Google homepage in English?

You can access the standard Google homepage by clicking on the "Google in English" link from any of our foreign language homepages. If this does not work, your browser is probably not configured to accept cookies.

once you're at the english page, you can set your pref to always return results in english

more tips here:
https://www.google.com/help/faq.html