> Take VS+:  To charge an capacitor from 0 to 10v or more potential takes
> more power than charging it to 5v wich would be 10v thanks to the 5v
> offset if connected as manufacturer reccommends.  Result is longer
> startup time, but yes it may work.

This is just plain wrong.  In either case, the capacitor starts at 5V with
respect to ground and ends up at 10V.  The incremental charge to get it
there is the same regardless of where the other end is tied.  The only
difference is the voltage rating required of the capacitor.  As long as
the other side of the capacitor is tied to a voltage with no AC component
(constant with respect to ground), the charge pump will operate
identically.  dQ still equals C * dV either way.

The real issue is where you want to dump the ripple current.  I prefer to
keep the supply rail as clean as possible, so I bypass the MAX232A at the
chip and tie the other end of the +10V capacitor to ground.


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