At 06:22 PM 2/20/02 -0500, Sean H. Breheny wrote: >I haven't followed this from the beginning, so perhaps I am missing >something, but you have to remember that you won't be able to turn the >MOSFET off if the drain is more negative (or positive for PMOSFET) than the >body (usually connected to the source). In other words, it is true that it >conducts in both directions when fully on, but it will still conduct in one >direction when off. This is due to the inherent diode (body diode) created >by the PN junction between drain and body (substrate), and the fact that >the source is usually connected to the body. What you are missing is that there are 2 series-connected MOSFETs wired in series with the load such that the Source leads are tied together, as are the gate leads. The switch terminals are the 2 Drain leads. 1 FET handles 1 half-cycle, the other FET handles the remaining half-cycle. So, yes, one FET does not turn off on a given half-cycle. But the other one does. dwayne Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 18 years of Engineering Innovation (1984 - 2002) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu