On Jun 18, 2011, at 8:29 PM, V G wrote: >> What is this minimum impedance and why is it there? > I wasn't really understanding the question, but: Vcesat ? BillW --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .