Probably need more info to give a better answer. How fast does it have to operate? In other words, how much current does the gate driver have to supply and how fast? How much drive current do you have available from your gate signal? Are there any start-up requirements? IOW - does it matter how the gate drive behaves during start-up? How much current can suck from the 10V to 20V rail? Is a passive pull-up on the gate to your 10..20V rail fast enough? Where am I going with this? If all that you are doing is turning some load (lights or motors) ON or OFF, the first thing that comes to mind is a simple common-base (cascode style) single transistor level shifter. Hold the base somewhere near your logic HI level, with a 1K resistor in series with the base. Emitter goes to your gate drive signal. Collector goes to the FET gate, with whatever pull-up resistor you choose to the high voltage rail. Add a zener between G&S if the high-voltage rail is too high. If you don't really have a logic-HI rail to drive the base from, use a LED as a simple shunt regulator and feed the base of the transistor from that. Logic LOW on the gate drive signal holds the FET gate LOW. Logic HI on the gate drive signal turns the transistor OFF and allows the pull-up resistor on the FET gate to turn the FET ON. Disadvantages: high quiescent current, slow. Advantages: cheap. dwayne At 08:29 AM 3/5/2008, Apptech wrote: >Wanted: FET gate driver circuit that allows operation on a >supply voltage down to 3 volts with drive signals of say 2V >nominal but FET gate drive in the 4V - 10 V range. Cost and >component count to approach zero in large volumes :-). >Should be reasonably compact. In this case I also have >available a voltage of either 10V nominal or 20V nominal >(changes semi-arbitrarily to one of those two values) which >could be used for gate drive powering. An IC solution is >unlikely to be satisfactory (size, cost). -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist