Excellent design article from IR.
Extensive design information.
And an IC from IR :-)
    http://www.planetanalog.com/printableArticle.jhtml;jsessionid=VPKW4LFEPS0HAQSNDBCSKH0CJUMEKJVN?articleID=177105232

Ref: Ken Mardle

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist