> For applications that DEMAND the Tantalum's capabilities consider
> using a SOLID aluminium capacitor instead.

Just to be picky.
A Tantalum cap _is_ a Solid Aluminium electrolytic cap. Tantalum
is one type of the family 'Solid Al'. Another type is Manganese
Oxide (I think) which Philips market as Solid Al, preventing other
solid Al cap makers from using the term. Ain't trademarks et al
wonderful.

Since both are are solid Al, the performance is about the same and
they age about the same. The difference is that tantalum's
breakdown characteristics get worse with heat. So both ambient
heat and internal heat (especially due to ripple currents) effectively
reduce the operating voltage.
This characteristic is also a problem when they do fail. The Philips
parts will short with a bit of resistance and get really hot and stay
that way (pending any protection) and maybe blow the top off.
When a tant gets really hot, there is more breakdown which
generates more heat which causes more breakdown and so on,
leading to flames.

By the time you size them with some voltage overhead, temp
overhead and made allowances for ripple, you are probably just as
well off with a couple of wet electros and a decent sized ceramic.

Steve
======================================================
Steve Baldwin                Electronic Product Design
TLA Microsystems Ltd         Microcontroller Specialists
PO Box 15-680, New Lynn      http://www.tla.co.nz
Auckland, New Zealand        ph  +64 9 820-2221
email: steveb@tla.co.nz      fax +64 9 820-1929
======================================================

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