voltage regulator help - ot

[NavMicroSystems]

...to break it down, I need [email protected], [email protected], and [email protected]. Each controlled via hpwm from the pic.

Brian,
Let's assume the average supply voltage is around 13V
that gives a total loss of about 60W!

Earlier you were talking about a "low power solution"

You should think about a different and more economical approach (switching rather than linear).

Don't focus on those expensive "fully integrated" switching regulators,
there are several "low cost" SMPS-controllers available that give good results and high efficiency if you use the right external components.
Take special care on the inductors, capacitors, mosfets and diodes
and last but not least the PCB layout.

With one of my current designs I get close to an efficiency of 90% at competitive costs.
(SEPIC Converter 120W - Input 8-18V Output 12V@10A)