>>  FWIW I've used the 1117 for many designs and love it. It 
>> just works, and
>>  seems to be able to take quite a beating.

> Did you need tantalum caps on both the input and output?

*NO* regulator 'needs' tantalum caps on the input :-)
Tantalums turn spikes into smell, smoke, noise, flames and 
explosion, followed by a hard short across the terminals  - 
I've encountered all of these in a single event - in 
approximately that order.  Even a low energy spike that 
exceeds their voltage rating can punch through the oxide 
layer that forms the "electrolyte" and then the main power 
takes over and enlarges the 'hole'.

If you can GUARANTEE that there will NEVER be voltages 
present that EVER exceed the rated voltage then they are 
very compact compared to most alternatives.

However, solid Alumin(i)um caps, not to be confused with wet 
electrolyte ones, have a similar capacitance density and do 
not suffer from the same problems.

Tantalum MAY be OK as an output cap on a regulator. but a 
solid Al does as well.


        Russell


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