Oli Glaser wrote:
> Yes, I seem to remember Olin mentioning doing this, be good to have a
> look at his circuit.

There are many variations.  I did a Masters course on this concept five
years ago.  Several examples are in the USBProg design,
http://www.embedinc.com/products/usbprog/eusb2.pdf, although none of them
use a trick I came up with more recently to use a PNP with a LDO to keep th=
e
switcher output one junction drop above the LDO output.  The absolute
voltage reference in the 10F204 is rather sloppy.  I just checked, and I di=
d
use that trick on the ReadyBoard-02,
http://www.embedinc.com/products/ready02/qprot6.pdf.


********************************************************************
Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products
(978) 742-9014.  Gold level PIC consultants since 2000.
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.