Jamil,


>I've built some switchers and I think your best bet it to use the switcher
>as a preregulator then a linear at the output of the switcher.  Switchers
>have worked very well for me when you are careful to follow the design
>instructions and curves etc. on the datasheets.  Just make sure you are
>using the right caps, inductors etc. (they even give you part numbers from
>different manufacturers on the national datasheets).


I am now seriously considering running the switcher to output 12 V (I need
12 V at 500 mA or so anyway), and then to use a linear regulator to 5 V.
That should work fine when I take the power dissipated into consideration.

Thanks for the help
 Roland