>I'm using an oldy but goody in one of my current projects: National
>Semiconductor LM2623. Starts at 1.1V, runs from 0.8V through 14V,
>internal switch is good for better than 2A, tiny 4.7uH inductor. I'm
>powering it with 2x 1650 mAH NiMh prismatic cells (in series) with
>excellent results.
Linear Technology also have a range of switcher chips designed for low
voltage input. Many are designed for use in cell phones and similar consumer
equipment, so come in horribly small packages, but there are also a number
that come in more manageable packages like SOT-23 and SO-8. They also are
happy to supply a couple of chips as samples for free, if you go through
their web page.
Another trick with Linear Technology is their Spice program which is
designed as a sales tool for their chips, so it has much of the range as
standard items that you can select. The program is totally free and you just
need to follow the download links from the home page.
For the required inductor, there are several companies can supply these.
Coilcraft is one I have used, and they also have a sampling program, but
there are others listed in the LT datasheets. It also pays to use the
capacitors recommended in the datasheet, as well as a PCB layout that is
very close to examples they give.
http://www.linear.com/index.jsphttp://www.coilcraft.com/--
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
