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Good low leakage electrolytic caps?

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cvanc:
Hi all-

So I use and like the Nichicon UKL series of low leakage electrolytics.  These have served me well but I am curious to know of other brands/series that I should also consider.  Anyone got other types they like?  Thanks.

http://www.nichicon.co.jp/english/products/pdfs/e-ukl.pdf

cvanc:
Answering myself here...

I found the Vishay/Sprague TVA 'Atom' electros are low leakage, although they are available only in axial form factor
https://www.mouser.com/datasheet/2/427/tvatom-266625.pdf

Vishay/Sprague also has large beer can computer grade caps that are low leakage.  This isn't what I'm looking for but here's the datasheet
https://www.mouser.com/datasheet/2/427/36ddedx-239977.pdf

I haven't found any other vendors playing in this space, which kind of surprises me.

Kleinstein:
With electrolytic caps leakage is hard to separate from dielectric absorption. At least it is a very lengthy procedure. This a good argument to avoid specs that are too tight in this area.

Not many applications need really low leakage electrolytic caps (maybe buffering small batteries) so not that much demand.

MagicSmoker:
Low leakage and electrolytic capacitor don't really go together, but given that leakage goes up with temperature, capacitance and percent of rated voltage applied, you can obviously arrange circuit conditions - if not environmental - in your favor: use the smallest capacitance with the highest voltage rating possible. Also possibly relevant is that the aluminum oxide dielectric tends to degrade after some time (undefined) without a bias voltage applied, so leakage tends to be highest in the first few seconds to minutes after voltage is reapplied.

Other than that, consider a different dielectric is minimizing leakage is really important.

Obsolete units:
If you need really low leakage, at 1uA or less, wet tantalum takes a lot of beating. But you need deep pockets - the Vishay SuperTan series are hundreds of dollars *each*. Carefully selected aluminium electrolytics will reach that sort of leakage if left with a stable voltage for a day or two, and orders of magnitude less cost.

Jim Williams Linear Tech Apps note 124 describes a low noise low frequency technique that uses a 1300uF 30V wet tant that costs over $400 - but he needs nA leakage current. And even that cap takes 24 hours to charge

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