> Sorry input would be the 13.8V-14.4V car system.
>
> > +12V @ 2.5A and +5V @ 1A, what is the best solution can have +/-10% on
> them.
> >

Richard,
    The 12 Vdc will be a small problem for you.  The output voltage is very
close to the input voltage. I doubt that a switcher is very practical for
this low of an input. I recommend an LDO like the LMS1585CSX-ADJ. A simple
switcher for the 13.8 Vdc to 5 Vdc will be reasonable and fairly small.
There will be very little heat less than 5W in the 13.8 Vdc to 12 Vdc. Also
consider how important it is to stay regulated at 12 Vdc. The battery of the
vehicle can drop below 12 Vdc at start up and in case of lights left on, the
battery may drop to 10 or 11 Vdc or lower. If you require 12 Vdc regulated
under these conditions consider a buck-boost regulator.

Gordon Varney

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