Solid Aluminium vs. Tantalum Caps

[Costas Vlachos]

I've always known and admired the superior properties of Tantalum caps.
BUT... I've been reading posts in sci.electronics.* and elsewhere about how
they can turn into nice fireworks/explosives, or can fail easily under harsh
conditions. I've been looking at the so called "solid aluminium" caps (not
the aluminium electrolytic ones), which are supposed to have a very long
life, and ESR comparable to Tantalums.

How do the two compare? Would you use solid alu caps in place of Tantalums,
and if not, what makes Tantalums better?

Thanks for any comments.

Costas

 

[Jim Adney]

On Wed, 23 Jul 2003 17:25:52 +0000 (UTC) "Costas Vlachos"
<c-X-vlachos@hot-X-mail.com> wrote:

I've always known and admired the superior properties of Tantalum caps.
BUT... I've been reading posts in sci.electronics.* and elsewhere about how
they can turn into nice fireworks/explosives, or can fail easily under harsh
conditions. I've been looking at the so called "solid aluminium" caps (not
the aluminium electrolytic ones), which are supposed to have a very long
life, and ESR comparable to Tantalums.

I've heard of solid tantalums but not solid aluminums. Are you sure?
Do you have a URL?

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------

 

[Costas Vlachos]

"Jim Adney" <jadney@vwtype3.org> wrote in message
news:0kkuhvkaihhps92tkah78m6dle3op6qivg@4ax.com...

On Wed, 23 Jul 2003 17:25:52 +0000 (UTC) "Costas Vlachos"
c-X-vlachos@hot-X-mail.com> wrote:

I've always known and admired the superior properties of Tantalum caps.
BUT... I've been reading posts in sci.electronics.* and elsewhere about
how they can turn into nice fireworks/explosives, or can fail easily
under harsh conditions. I've been looking at the so called "solid
aluminium" caps (not the aluminium electrolytic ones), which are
supposed to have a very long life, and ESR comparable to Tantalums.

I've heard of solid tantalums but not solid aluminums. Are you sure?
Do you have a URL?

Yes, they do exist. Strictly speaking they are still aluminium electrolytic,
but with solid electrolyte (not liquid like the usual ones). Go to:

http://www.bccomponents.com/

Select electrolytic caps and you'll see them as "solid aluminium". There are
PDFs there too. Check http://www.farnell.com/datasheets/361.pdf for one of
them. They're supposed to have very low ESR (comparable to tantalums), but
are more tolerant to abuse (they can even tolerate reverse polarity up to
0.3*rated voltage, and don't need low-ohmic resistors to protect them from
abrupt charges/discharges).

I've ordered a few 10uF solid alu ones for testing. They are made by Sanyo
and the specs are: 10uF @ 10V, ESR of 150 mOhms @ 100kHz to 300kHz, -55*C to
105*C, 5mm diameter, 6.8mm height, Ł0.40 each (UK/Farnell).

cheers,
Costas