I've used the LT1944-1 (http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1042,C1035,P1704) dual boost converter in a couple products. It works down to 1.2V. Harold -- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available! -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist