> I know there are dc to dc converter and voltager doubler IC's
> available from companies like Maxim, but I would still like to hear
> the opinions of other list members about the usage of these types of
> voltage doubler IC's.  Since there will also be a 5V, 12 bit A/D on
> the circuit, I need something that is not very noisy and still quite
> efficient.   I have never had to make such a battery operated
> product before.  What would you recommend or not recommend?  Is it
> feasible to run a 5V based circuit from a 20 - 2.4V  supply with dc
> to dc conversion, or is it not recommended?

We manufacter a handheld temprature indicator. 68HC711,24 bit A/D,4 7seg
LED display all run
off a MAX777 and 2 Ni-Cads.