bcjames wrote:
I want to build a 5 Volt power suppply to run my PDA in my
glider from the 12 volt battery. Sometimes I use a 14 volt
battery too, so it needs some input voltage range. I'm
looking for suggestions and a DigiKey part number for a
suitable 1 amp DC/DC integrated power supply chip.

I'd like:
at least 80% efficient
no radio noise
Vin of 10.5 to 16.5 volts
Vout 5 volts
1 amp
low cost

I've looked at the LM2825 and the LTC1174-5, but I'd like to
hear from anyone who's done this.

Thanks



Check out Maxim, they tend to be very helpful
with samples. They also have parts with ring
damping circuitry which would help with the
radiated noise.

Another option is to download LTSpice
( http://www.linear.com/software/ ).
That software has a switcher designer
wizzard, you enter your parameters and
it spits out a circuit you can simulate.

Depending on your experience and amount of
effort you want to spend, it may be worthwile
to look into DC-DC converter modules.

Kind regards,

Iwo